Immobilizer Glitch

[betyouaint]

*** THIS IS NOT AN IMMOBILIZER ISSUE - IT IS ALMOST CERTAINLY AN AIR FUEL TRIM ISSUE CAUSED BY A FAULTY MAF SENSOR***

I went to start the car this morning and it died almost immediately after starting up. I tried a couple more times with the same result - runs for a second and then dies. I know this to be a symptom of the immobilizer not recognizing the key, as one of my valet keys is mismatched and behaves in this same way. So I then tried my second key and also the "good" valet key but these too wouldn't allow the car to run for more than a second or two.

I did some reading around and heard much talk of an immobilizer light on the cluster. Unfortunately, I don't seem to have one, certainly not one that ever lights up. Should my year/model have this light?

The other thing I read about was a bad pickup for the RFID in the key. It was referred to as the "dreaded pickup" like it was something common but then judging by the scarcity of useful posts, maybe it's not that common.

I was just about to go into full fault diagnosis mode, breaking out the VAGCOM, disconnecting the battery, when I read something about possible pickup connection/wiring issues. So I gave the ignition barrel a little "percussion adjustment" and moved the steering wheel adjustment up and down a couple of times. And what do you know, it fired up and stayed up...!!!

Not sure how long this fix will keep things going so I just wanted to check if anyone out there had experienced similar issues and managed to permanently fix what I suspect to be a wiring problem with the immobilizer pickup?

[allstock]

There might be a code. Wouldn't hurt to check. Good that you got her running.

[betyouaint]

CORRECTION...!!!

001299 - Incorrect Immobilizer Key
P0513 - 008 - Implausible Signal - Intermittent

She still runs a little rough for a while after starting.

Does the RFID need to be in proximity all the time the engine is running or only for the first "X" seconds after starting...?

[betyouaint]

http://wiki.ross-tech.com/wiki/index...7/P0513/001299

I did find a TSB for this problem on the VW Passat but nothing on the Audi

[betyouaint]

Can anyone confirm that this B6 DIY will get me to the ignition barrel on my B7 so that I can check out the wiring to the RFID pickup coil?

http://www.audizine.com/forum/showth...ch-Replacement

[betyouaint]

The car wouldn't stay running again when I tried it this morning. Even after a few thumps and wiggles around the ignition barrel it didn't fire up. I also noticed that the Trip meter was displaying the word "SAFE".

Next, I tried something I read here...

http://www.myturbodiesel.com/wiki/im...lacement-tips/

...regarding leaving the ignition on for 10 minutes and trying again. This seemed to do the trick and the car started and ran for a few minutes before I shut it off and took my van to work instead.

When I arrived home tonight, it wouldn't start (stay running) again so I tried the 10 minute trick and it worked. Feeling confident I went for a drive around the neighborhood. Unfortunately, about a mile from home the engine started to misfire and I barely made it back. I re-ran VCDS but the immobilzer code wasn't there, just a bunch of misfire codes. However, I then ran a full scan of all modules and turned up some interesting codes from the HVAC system and steering wheel that mentioned the immobilizer...!!!


Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043 BM
Component: A4 Klimaautomat 2832
Coding: 00000
Shop #: WSC 00000
VCID: 6DDACBEA4BCBE874

1 Fault Found
00474 - Control Module for Immobilizer
49-10 - No Communications - Intermittent

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 8E0-953-549.lbl
Part No: 8E0 953 549 Q
Component: Lenksáulenmodul 0601
Coding: 02021
Shop #: WSC 06335
VCID: 4182475A27D3DC14

1 Fault Found
00474 - Control Module for Immobilizer
49-10 - No Communications - Intermittent

-------------------------------------------------------------------------------

The full scan is given below:


Monday,21,March,2016,18:01:13:46862

Chassis Type: 8E - Audi A4 B6/B7
Scan: 01 02 03 08 09 0F 11 15 16 17 18 36 37 45 46 55 56 57 65 67
69 75 76 77

VIN: WAUDF78E......... Mileage: 238130km/147967miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 06F-907-115-AXX.lbl
Part No SW: 8E0 910 115 M HW: 8E0 907 115 D
Component: 2.0l R4/4V TFSI 0070
Revision: --H13--- Serial number:
Coding: 0104010A190F0120
Shop #: WSC 08144 444 84095
VCID: 2B5E05F2B55F2644

6 Faults Found
004243 - Bank 1; Fuel Measuring System 2: Malfunction
P1093 - 008 - Implausible Signal - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 1
Mileage: 238131 km
Time Indication: 0

Freeze Frame:
RPM: 1909 /min
Load: 37.2 %
Speed: 64.0 km/h
Temperature: 72.0°C
Temperature: 6.0°C
Absolute Pres.: 980.0 mbar
Voltage: 14.224 V

000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 - Upper Limit Exceeded
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Mileage: 238132 km
Time Indication: 0

Freeze Frame:
RPM: 2405 /min
Load: 36.8 %
Speed: 32.0 km/h
Temperature: 75.0°C
Temperature: 6.0°C
Absolute Pres.: 980.0 mbar
Voltage: 14.097 V

000769 - Cylinder 1: Misfire Detected
P0301 - 001 - Upper Limit Exceeded
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Mileage: 238132 km
Time Indication: 0

Freeze Frame:
RPM: 2405 /min
Load: 36.8 %
Speed: 32.0 km/h
Temperature: 75.0°C
Temperature: 6.0°C
Absolute Pres.: 980.0 mbar
Voltage: 14.097 V

000771 - Cylinder 3: Misfire Detected
P0303 - 001 - Upper Limit Exceeded
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Mileage: 238132 km
Time Indication: 0

Freeze Frame:
RPM: 2731 /min
Load: 32.1 %
Speed: 20.0 km/h
Temperature: 78.0°C
Temperature: 8.0°C
Absolute Pres.: 980.0 mbar
Voltage: 14.097 V

000770 - Cylinder 2: Misfire Detected
P0302 - 001 - Upper Limit Exceeded
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Mileage: 238132 km
Time Indication: 0

Freeze Frame:
RPM: 2731 /min
Load: 32.1 %
Speed: 20.0 km/h
Temperature: 78.0°C
Temperature: 8.0°C
Absolute Pres.: 980.0 mbar
Voltage: 14.097 V

000772 - Cylinder 4: Misfire Detected
P0304 - 002 - Lower Limit Exceeded
Freeze Frame:
Fault Status: 01100010
Fault Priority: 0
Fault Frequency: 1
Mileage: 238132 km
Time Indication: 0

Freeze Frame:
RPM: 1945 /min
Load: 33.3 %
Speed: 48.0 km/h
Temperature: 80.0°C
Temperature: 10.0°C
Absolute Pres.: 980.0 mbar
Voltage: 14.097 V

Readiness: 0010 0101

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 09L-927-760.lbl
Part No SW: 8E1 910 156 C HW: 09L 927 156 B
Component: AG6 09L 2.0TFSI USA 0040
Revision: --H01--- Serial number: 4152649
Coding: 0000002
Shop #: WSC 06335 000 00000
VCID: 2756F9C2A9B70224

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 8E0-910-517.lbl
Part No SW: 8E0 910 517 E HW: 8E0 614 517 AL
Component: ESP8 quattro H06 0120
Revision: 00000000 Serial number: 00000000000000
Coding: 0004528
Shop #: WSC 06335 000 00000
VCID: 2952FFFABFA33454

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043 BM
Component: A4 Klimaautomat 2832
Coding: 00000
Shop #: WSC 00000
VCID: 6DDACBEA4BCBE874

1 Fault Found
00474 - Control Module for Immobilizer
49-10 - No Communications - Intermittent

-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 8E0-907-279-8EC.lbl
Part No: 8E0 907 279 L
Component: int. Lastmodul ECE 0704
Coding: 01001
Shop #: WSC 65536
VCID: 3B7E35B2453FB6C4

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8E0-959-655-94.lbl
Part No SW: 8E0 959 655 H HW: 8E0 959 655 H
Component: Airbag 9.41 H12 3840
Revision: 91H12384 Serial number: 0036N001NFUF
Coding: 0032607
Shop #: WSC 06335 000 00000
VCID: 3C7C36AE4031B1FC

Part No: 8E0 910 339 B
Component: BF-Gewichtsens. 002 0070

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 8E0-953-549.lbl
Part No: 8E0 953 549 Q
Component: Lenksáulenmodul 0601
Coding: 02021
Shop #: WSC 06335
VCID: 4182475A27D3DC14

1 Fault Found
00474 - Control Module for Immobilizer
49-10 - No Communications - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8E0-920-9xx-8EC.lbl
Part No SW: 8E0 920 951 G HW: 8E0 920 951 G
Component: KOMBI+WFS 4 H14 0110
Revision: 0110 Serial number: 00000000000000
Coding: 0023259
Shop #: WSC 01308 444 70096
VCID: 2E580CE6864D536C

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 8E0-959-433-MAX.lbl
Part No: 8E0 959 433 CG
Component: Komfortgerát T7B 4035
Coding: 11896
Shop #: WSC 06335
VCID: 78F4EABE34895DDC

Part No: 8E1959801G
Component: Tõrsteuer.FS BRM 0706

Part No: 8E1959802G
Component: Tõrsteuer.BF BRM 0706

Part No: 8E0959801E
Component: Tõrsteuer.HL BRM 0606

Part No: 8E0959802E
Component: Tõrsteuer.HR BRM 0606

4 Faults Found
01371 - Alarm triggered by Door Contact Switch; Driver's Side
35-00 - -
00957 - Key 3
35-10 - - - Intermittent
01559 - Drivers Door
57-10 - Electric Circuit Failure - Intermittent
01340 - Mirror Adjustment Switch
27-10 - Implausible Signal - Intermittent

-------------------------------------------------------------------------------
Address 56: Radio Labels: 8J0-035-1xx-56.clb
Part No SW: 8E0 035 195 AC HW: 8E0 035 195 AC
Component: R Symphony2+ H02 0070
Revision: 00H02000 Serial number: AUZ1Z4F1831804
Coding: 0310112
Shop #: WSC 01126 444 66585
VCID: 68D4BAFE6429CD5C

1 Fault Found
00821 - Antenna 2 for Radio (R93)
011 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00101011
Fault Priority: 5
Fault Frequency: 2
Reset counter: 113


End ---------------------------------------------------------------------

[betyouaint]

So, by way of an update...

I pulled the steering wheel and cowling and I can't see any wiring issues. It's hard to do a continuity check when you don't know where the other end of the wires go. I left the lower cowling off and put the steering wheel and airbag back on so that I could manipulate the wiring with everything powered up. Again, the car wouldn't run for more than a few seconds before conking out. Oddly, no immobilizer codes anymore though, nor any SAFE message in the ODO

I've found that if I leave the ignition on for just a couple of minutes, the car will fire up and stay up and even drive quite well for about 5 minutes before it starts to lose power and stutter. I took it for another risky drive round the neighborhood tonight and even under reasonable acceleration things seem normal for the first few minutes. When I got back, I ran the diagnostic (no check engine light) and pulled the fuel measurement code again...

004243 - Bank 1; Fuel Measuring System 2: Malfunction
P1093 - 008 - Implausible Signal - Intermittent

Does the immobilizer cut the fuel...? Is that why I'm seeing this code for what seems like an immobilizer problem?

No misfires this time but I did check the HVAC and Steering Wheel modules and they both had this code again...

00474 - Control Module for Immobilizer
49-10 - No Communications - Intermittent

I'm assuming they must be new as I left the battery off overnight and discharged the leads by shorting. I'm not deliberately resetting codes right now in case I have to go to the dealership. They're pretty clueless even with the codes. Without them (even if I give them a VCDS printout of the codes I pull) they just stand around scratching their balls.

Below are some photos of my ignition barrel for anyone who's interested...

[mtroxel]

Does the immobilizer cut the fuel...? Is that why I'm seeing this code for what seems like an immobilizer problem?

I don't believe so. I'm not an expert on the immobilizer system, but here's what happened to me a couple weeks ago:

Start the car, starter turns slowly but motor starts, runs 2 seconds, turns off and SAFE in the odometer. VCDS and found battery voltage was only 11.3 V, and a couple errors about "Immobilizer coil signal" from the inst cluster and somewhere else, can't remember. But, there were no misfires like you are seeing and no fuel "measuring system implausible" stuff like you see. In my case I charged up the battery (I had been messing around with the ignition on along with the heated seats, HVAC, etc.) and all was forgiven.

But based on my little drama a couple weeks ago, I'm going to guess that your fuel signal error is related to the misfires, but I didn't see those errors when my immobilizer cut me down a couple weeks ago.

[betyouaint]

The second time out, there were no misfires, just the fuel measurement issue. It definitely felt like a fueling issue and no misfires were registered, nor did it feel like it was misfiring. No jerking and bucking like the first outing - the power loss was smoother though I may have been driving smoother too...

My battery is at 100% with a standing voltage in excess of 12.5V. That's not to say that there isn't a power rail issue somewhere in the system. Is there somewhere else I can check the electrical power levels using VCDS?

I've only seen the 'SAFE' indication on a single occasion. The whole thing seems very marginal (I hesitate to say intermittent, which suggests more on and off) with the whole system balancing on the edge of serviceable/unserviceable.

Right now, I'm trying to understand the reasons why:
1. If the car doesn't stay running when starting in the first couple of minutes, why if I just leave the ignition on for a couple of minutes before turning starting, the engine stays running?
2. After getting the engine to start, why does it drive fine for the next 5 minutes before I then start to experience the power loss (fueling and misfires)?

There's this sweet spot when everything seems fine.

[mtroxel]

My battery is at 100% with a standing voltage in excess of 12.5V. That's not to say that there isn't a power rail issue somewhere in the system. Is there somewhere else I can check the electrical power levels using VCDS?

I wasn't saying you might have a voltage problem just because I did. Sounds like you can start your car over and over and it never runs long enough to re-charge. That alone makes me think your battery is happy.

There's this sweet spot when everything seems fine.

Your whole story makes me think fuel pressure. One of the pumps, fuel pressure regulator, something along that line. It's as if you turn on the ignition for a while before you start it to build pressure, then as you drive for a while the pressure drops again till you're starving.

The SAFE error you had probably was the immobilizer. But two problems at the same time are not always related.

[p0isin]

This is a tough one. Part of me is thinking you may have a loose wire or poor ground connection somewhere which is leading to random electrical faults. Good luck with the diagnosis.

[betyouaint]

I checked the codes again tonight after another short static run last night - No fuel codes but the misfire codes were back.

Tonight, I cleared everything including the 2 immobilizer codes on the HVAC and steering wheel and went out for another run. As the ignition had been on for a while to run VCDS, the car fired right up and stayed up. Again, the first few minutes were fine and I was watching the temp gauge to note when things started to deteriorate. Literally, as the needle hit its "normal" mid point on the gauge, the car started to lose power.

I limped home and ran the codes with the car still running. Same fuel measurement code was there but no misfires. I left the car running and tried to clear the code but it would immediately pop up again, over and over. Eventually I shut the engine down and cleared it. I started her up again and it did not return.

As everything was warmed up, I decided to run "Readiness". I ran it 3 times and everything passed except the oxygen sensor. I'm now wondering if this could be part of the issue, especially given that some of the major symptoms occur literally as the car reaches temperature.

Is this when the O2 control loop goes fully closed loop?

Maybe things are fine while the O2 monitoring is open loop using defaults?

Could the fueling/misfire symptoms be caused by a failing O2 sensor?

Is it possible that the failing immobilizer symptoms (stalling out within 1-2 seconds) may be caused by a failing O2 sensor?

Odd that there are no O2 codes given that readiness fails on the sensor. What other diagnosis can I do to narrow down to or eliminate the sensor and which of the 2 O2 sensors may be at fault?

[betyouaint]

I wasn't saying you might have a voltage problem just because I did.

No, I understand but I've learned not to count anything out.

Your whole story makes me think fuel pressure. One of the pumps, fuel pressure regulator, something along that line. It's as if you turn on the ignition for a while before you start it to build pressure, then as you drive for a while the pressure drops again till you're starving.

I kinda wondered about the build up of pressure too but the low pressure fuel pump primes the system when the door is opened, not when the ignition is turned on (like many of my previous cars). I had the full HPFP/camshaft/follower work done around 2 years ago and then spent almost a year chasing additional apparent fueling issues that caused loss of power and countless fuel codes. I changed almost everything else in the fuel system, LPFP, HP sensor, LP sensor, return/bypass valve, you name it. In the end it was a camshaft sensor that had been contaminated by metal shavings from the cam follower failure. As a result, the ECU was seeing something funky and was deliberately cutting the fuel but then throwing codes for low fuel pressure. Schizophrenic ECU with 2 personalities that don't talk to each other...!!!

This is a tough one. Part of me is thinking you may have a loose wire or poor ground connection somewhere which is leading to random electrical faults. Good luck with the diagnosis.

Yeah... nothing is as it seems with this one. I have to wonder if some chipmunk has been keeping warm under the hood and eating through the wiring...

I'm willing to put the whole thing down to poltergeist activity and bring in a exorcist...

[betyouaint]

I did some more fiddling around this morning. After seeing the fueling issues and describing my previous history in a reply to mtroxel above, I wondered if there was any chance that the camshaft sensor was once again causing issue with the fueling. So, first job was to remove and inspect and sure enough, there was some metallic contaminant build up. For dramatic effect, I decided to video the removal of the particles with a magnet as shown in the video below:



Although there wasn't nearly as much gunk on it (as there was last time I was having fueling issues) and the symptoms aren't exactly the same I was seriously hoping that this could once again be a simple fix. I cleaned it and reinstalled.

Unfortunately, when I tried to start the car, it would again cut out within a few seconds. Didn't seem like I'd found the miracle cure.

However, I decided to wait the obligatory few minutes with the ignition on that then allows the car to be started and then run a VCDS log while driving so that I could catch the point deterioration and maybe tie it in with some specific parameters... coolant temp, various lambda values, HP and LP fuel pressures, rpm and a few others. What I found was that as I drove and logged the data, I couldn't recreate the power/fueling issue - no symptoms and no codes at all...!!! So I drove further... and further (actually round in circles so I wasn't too far from home) and couldn't get it to fail. It seems like the post warm-up issue has disappeared, for now at least. I'm feeling brave enough to drive to town to pick up Chinese food... fingers crossed

As yet, I haven't had chance to start from cold so I don't yet know the state of the starting issue. Watch this space if you're interested.

[mtroxel]

It's a good one. Since you've got VCDS, check the duty cycle on the lpfp. Anything in the 60%-70% range means it on the way out. Have you ever changed the fuel filter back there?

[betyouaint]

Unfortunately, the miracle cure was short lived. The car behaved flawlessly for 15 of the 16 mile round trip to the Chinese takeaway but about a mile from home it started to lose power again. On the way out I ran logs but I didn't bother on the way back home when the problem returned. I did pull to the side of the road to restart the log but when I set off again, all seemed fine again. I'd done a few WOT runs on the outbound leg and not a hint of a problem.

I changed the LPFP and filter about 18 months ago as part of my previous issues. I got the Siemens VDO pump from Europaparts. I think I put a DIY up on here but here's the identical DIY on AW:

http://www.audiworld.com/forums/a4-b...attro-2869550/

I'll review the logs and see what the LPFP is doing. I did include it in the parameter set and I'm pretty sure I saw it at 60+ % at one point when I was revving up in the garage. The fuel code was back and this time it was accompanied by an air leak code too, one I'd not seen before.

I'd hate to think it's the LPFP, especially after I literally just filled up the night before this problem started. Maybe I got some dodgy gas...!!! Would be a pain to drain it to get the pump out. Luckily, I did keep the old one, which I'd changed on spec due to my prior fueling issues. The new one didn't fix the problem, which as I said earlier, was down to the camshaft sensor.

The only other thing I touched today was the wiring harness against the bulkhead, which includes the O2 sensors and the air meter. When the Audi dealership did the HPFP/cam/follower job, they never put the harness supports back in place so it's just sitting against the back of the engine. I've tried locating the mount points to push the plastic studs in but haven't located them. I'm wondering if my temporary fix was due to me disturbing the harness...?

[mtroxel]

Yea it would suck to pull that pump with the tank full. I had to pull the fuel level sender on my B5 with a full tank at 10˚ F. Up to my elbow in smelly 10˚ fluid.

I saw you speculate once that it has to do with reaching operating temperature. Maybe you go get more Chinese: when it starts running badly pull over and sit with the ignition on while you eat some kung pao. Start it up again and if it runs fine, maybe you move temperature down the list.

You don’t even have to log the duty cycle on the lpfp. In fact it should be higher when the motor is under load. The 50% standard is at idle. I’d wonder what group 106 reads when you idle after your 10 second ignition pause, then again when it’s running crappy.

Was the immobilizer SAFE thing just a one time symptom?

[betyouaint]

The Chinese was excellent and would have made up for being stranded at the side of the road...

Did some runs this morning and managed to capture some useful data. Judging by the logs, it doesn't seem like fueling is the issue here.

http://www.legoheads.com/Log1.xls

http://www.legoheads.com/Log2.xls

The first log is taken from before just before starting the engine through to when the power issues first manifested, shortly after marker 1 (column A). Unfortunately, it's difficult to see when the problem occurs. It's possible to see some up-down-up-down fluctuation in the rpm, which shows the demand for acceleration and the almost immediate failure to meet that demand.

For the second log (technically just an extension of the first run), I added in the throttle pedal demand and the throttle drive response. This way, at least you can see when I was asking the car to go and the failure of the car to respond to that request. Below are 2 snippets taken from the second log, the first showing a healthy response to throttle pedal input and the second, a failure to respond.

From around frame 1018, the pedal angle is between 80-100%, with the throttle drive responding at almost 100%. I'm not sure what Lambda regulator represents in real terms but the values show a stark contrast with those in the "unhealthy" snippet. At this point the car seemed fine.




A similar throttle demand at frames 1112 and again at 1162 show the throttle drive failing to respond to the throttle pedal input. What is notable is the Lambda regulator value is in the 20s or at zero throughout much of the time when the power loss is present whether I'm on or off the throttle. Of course, this could itself be a symptom of something else but it's interesting non-the-less.




If I now go back to the first log, which also contains the Lambda - Regulator values, it's easy to see where the problem was occuring during that time too. All the time during warm up, the Lambda Reg. was mostly negative moving up towards single figure +ve and -ve values. I need to look back to yesterday's "Chinese Run" to see how this correlates there too.

[betyouaint]

And BTW... I still need to leave the ignition on for 2-3 minutes before the car will start cleanly. As previously stated...

1. when cold or ignition not on recently, the engine will die within 1-2 seconds of starting
2. if the ignition is left on for around 1 -2 minutes from cold, the engine may start but it will run lumpy for the next couple of minutes until things warm up
3. if the ignition is left on for 2-3 minutes the engine starts and runs fine
4. if the car has been run recently and is still "warm", it will start okay. This may be up to an hour or so after the last run?

I'm assuming that while the ignition is on, the O2 sensor heater is running?

[Okedokey]

Does your radio still work? Thinking the fuse behind it. Does your K line show good on the VCDS?

I would look into a PCV as well, as if this is leaking it can cause misfires etc.

[mtroxel]

Yea your lambda is way FUBAR in that 2nd log. I believe 25 is as high as VCDS will go. You're running way lean. I've watched that in my logs too. I might see 16-17 for one time stamp, but never 25.

Lean could be:

1. an air leak, but you should throw a code. And you would expect it to show more at idle than at half throttle like you were in log 2.
2. Not enough fuel. I don't know what those fuel rail pressures should be, but they are the same in the first log when the lambda is fine as it is in the second when the lambda is screwed.
3. O2 sensor that's lying. I think you're right about the heater being on with the ignition, but that's only used at cold temps, so it doesn't explain why your lambda goes FUBAR when you've driven for a while.
4. MAF problem, but it's showing 161 g/s at WOT like it should.

I'm out of my depth here. But I think the clue is in the 10 second pre-ignition thing that makes it run right....for a while. I keep coming back to my fuel starvation theory, but from what I know those fuel rail numbers are proving that wrong.

[betyouaint]

I'm kind of favoring 3. right now and here's my reasoning...

On 3 out of the 4 runs I've done from cold through warm up, the power loss has started manifesting just as the engine reached normal operating temperature. I'm making an assumption that this is the same point at which the ECU starts trusting the lambda instead of forcing a richer mixture for the cold engine. Also, the wait time (much longer than 10 seconds) that I need to leave the ignition on could suggest that the car won't stay running at all if the O2 sensor hasn't reached temperature. I'm not sure how this ties in from a technical reasoning standpoint but both the major symptoms may be tied in to some behavior of the O2 sensor, assumed or otherwise. The Chinese run was done after I had been "playing around" with the wiring and connectors for the O2 sensors.

One thing I want to try is to warm the sensor up using an external source and see if the engine will stay running like it does if the ignition is left on for a few minutes. This would then suggest that the non-starting issue is related to the O2 sensor warm-up. If not, then I may be dissuaded from this line of diagnosis.

In regards to fueling, from experience those pressures are fine. But then again, could it be the HP fuel sensor that's lying? In this case I do have a couple of spares including a brand new sensor I could try.

Funny that you mention an air leak as my post Chinese run threw a single code for an air leak along with a bunch of misfire codes. I didn't pay it much mind as it's the only time I've seen it throughout all my testing and assumed, like the misfires, it was a symptom rather than a cause.

008825 - Leak in Air Intake System
P2279 - 002 - Lower Limit Exceeded - Intermittent
Freeze Frame
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 1
Mileage: 238178 km
Time Indication: 0

Freeze Frame
RPM: 770 /min
Load: 16.5 %
Speed: 0.0 km/h
Temperature: 91.0°C
Temperature: 18.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 13.970 V


At this point, I think I'm going to throw a few parts at it and see if I can confirm or eliminate some causes. I just wish O2 sensors weren't so expensive. Don't really want to count on an ebay part to prove things out.

I'm now thinking the whole immobilizer thing may have been a red herring. The starting symptoms suggest immobilizer but it's possible the codes and "SAFE" came about from me trying all my keys, including at least one key that is known to have incorrect coding.

[betyouaint]

Does your radio still work? Thinking the fuse behind it. Does your K line show good on the VCDS?

I would look into a PCV as well, as if this is leaking it can cause misfires etc.

Radio is fine. Can you explain your train of thought?

PCV was changed a couple of years ago but that's not to say it's still good.

[Okedokey]

Simply thinking if your radio was out, the kline runs through the radio, meaning the immobliser will also be out. Secondly, a vacuum leak could result in incorrect air readings further confusing the o2 sensor. I had the same/similar issues and replaced the PCV and that is the second one in about 1 year.

[Biged243]

Earlier you stated that your car was running higher than 12.5 volts? What voltage are you actually seeing with the car running?

[betyouaint]

Earlier you stated that your car was running higher than 12.5 volts? What voltage are you actually seeing with the car running?

Around 14V...

Simply thinking if your radio was out, the kline runs through the radio, meaning the immobliser will also be out. Secondly, a vacuum leak could result in incorrect air readings further confusing the o2 sensor. I had the same/similar issues and replaced the PCV and that is the second one in about 1 year.

I did switch out the radio last year, upgraded to Symphony 2+. I know in doing this, I had to swap some wires and maybe one was the k-line? Still can't understand why the car acts like the immobiliser is on but only for the first few minutes and then it starts fine. Where does VCDS show the k-line? I don't see anything obvious.

One thing I tried when I got home tonight was to heat the O2 from the outside (as I discussed above) to see if the start delay was due to the ignition ON warming the O2 sensor. I applied a fair amount of heat with a blowtorch but the starting delay was till the same. That's one theory out of the window.

I also tried to recall the PCV test where you remove the oil cap but I'll have to look that one up. I recall that the cap is quite difficult to remove with the engine running due to vacuum but mine came off with very little effort. I also pulled the line from the PCV that connects to the intake plenum and the engine died immediately. Not sure if this proves anything.

[Okedokey]

When you test the usb connection, upon report, it will show you if the klines are good or not.

[betyouaint]

K-lines report fine.

Seems like the slight vacuum at idle is correct along with a rough idle with the cap removed. Not conclusive proof that the PCV is okay, but a good indication that it may well be.

Been trying to find other things that "warm up" in the first few minutes of ignition ON but no engine running...

[betyouaint]

What are these two plugs on in inlet to the air manifold?

I'm guessing one is the manifold air temp sensor... and the other is... the throttle actuator? The temp sensor measures around 3.6k at around 44F. I tried unplugging both of them and with the engine cold and no "ignition warm-up" time, the engine started up and ran, a little lumpy but it still ran and didn't die within 2 seconds as per my symptoms. I removed the temp sensor, cleaned it with some carb cleaner, refitted and reconnected. With just the other plug disconnected, the car stated and ran. With the temp sensor disconnected and the other plug connected, the engine died in a couple of seconds. To me, this suggests that my starting problem, and likely my post warm up running problems, may well have something to do with this actuator.

So, what is it...?

[mtroxel]

I believe that's intake air temp sensor.

[betyouaint]

I did a few more VCDS test runs tonight with different blocks.

The first log shows a healthy high throttle phase during engine warm-up, i.e throttle body responding to pedal input, mass air flow following suit, lambda is respectable range, etc.

The second shows the Lambda regulator figure in the mid-high 20s, even under light or minimal throttle input.

The third shows that even at idle, with lambda in normal range, very low airflow, etc. the Lambda regulator is still giving this very high figure.

What is the Lambda Regulator figure and how/ where is it generated? It seems that normal control operation dictates when lambda indicates lean, the Lambda Reg figure goes higher, probably to command enrichment of the mixture? So why at times, even idling slightly rich does this figure show so high?

[Okedokey]

The B1, S1 oxygen sensor. They tend to go out gradually rather than catastrophically.

[betyouaint]

The B1, S1 oxygen sensor. They tend to go out gradually rather than catastrophically.

But the lambda value looks fine; it's the lambda regulator value that's screwy. In my mind, this value must be a function of multiple readings and conditions (throttle demand, rpm, load, boost, engine temp, air temp, spec. lambda, actual lambda, etc.) that determined the correction to be applied to fuel/air to bring actual lambda closer to specified lambda.

As there are no codes for the lambda sensor, how can I test that the sensor is good/bad?

Also, is lambda assessed immediately after start? I didn't think it was as...
a) the lambda sensor hasn't reached temperature, and
b) the engine hasn't reached temperature
so the O2 is ignored...?

Also, what's the chance that this could be caused by bad fuel?

I filled up the night before I had issues and covered around 4-5 miles after the fill-up on the way home. Next morning, on start-up, is when the problem occurred.

[mtroxel]

Also, is lambda assessed immediately after start? I didn't think it was as...
a) the lambda sensor hasn't reached temperature, and
b) the engine hasn't reached temperature
so the O2 is ignored...?

Lambda is in "open loop" when the car is first started, as the O2 sensor is no where near the 600 degrees it needs to operate right. Once its heated, it's a closed loop, meaning the ECU trims the mixture, sees the change from the O2 sensor, then adjusts more. So, yea, it ignores the O2 at first. That might be the lambda 0's you see in some of your logs, but I'm not sure.

[Okedokey]

http://wiki.ross-tech.com/wiki/index.php/00537

[betyouaint]

Tonight's diagnosis effort is brought to you courtesy of the N80 evap purge valve...

This morning, I clamped the hose that feeds to the N80 (fuel tank inlet side) and drove to work in my trusty backup 2000 Toyota Sienna. When I got home I went to start the car. It fired up but then died within a couple of seconds, but not as convincingly as it has been dying. Unfortunately, the clamp I used isn't quite strong enough to completely seal the hose but I gave it an extra squeeze to see if it would seal a little better. Next attempt to start was more successful and it stayed up and running even if a little lumpy for the first few seconds.

I've not been for a drive yet but the fact that the car starts pretty well when I "plug" the evap line might suggest this could be a possible culprit?

I'm off to look for a description of operation for the N80 to see what it's supposed to do at start up, during warm-up and post warm-up. I'd also like to know if it's safe to plug the line and go on a longer run.

I do recall doing an N80 functional test with VCDS last week and it passed. Also, I don't have evap codes or leak codes. The only code I get in terms of AFR is the implausible fuel measurement.

[betyouaint]

Removed N80 and bench tested. No flow without power, flow on applying power. Sounds good to me.

Next up, I swapped out the LP fuel sensor with a spare I had lying around. I did the HP sensor a few days ago but it didn't help.

I then ran some O2 sensor tests according to...

http://audisrs.com/viewtopic.php?t=26914&start=0

All seemed fine although the pre-cat sensor was marginal on aging test - around 0.58 (new sensor = 2.0, out of spec <0.5)

After doing all this, the car was more than warmed up so I went for a quick test drive, which became a longer test drive and it ran flawlessly for around 25 miles, even under high boost and WOT runs...!!!

No idea what made the difference? Guess I'll wait to see how it starts in the morning after sitting overnight.

One observation was that the outside temp tonight was 65F. The last time it behaved okay, on the way to the Chinese, I recall it was a little warmer too. Mmmm...?

[mtroxel]

One observation was that the outside temp tonight was 65F. The last time it behaved okay, on the way to the Chinese, I recall it was a little warmer too. Mmmm...?

Didn't it also run better when you removed the intake air temp sensor? What if you VCDS that? Measuring block> group 4 shows it. Mine shows 31C right now when the ambient is 10C. Measure it now, then tomorrow AM when it's colder.

[betyouaint]

Didn't it also run better when you removed the intake air temp sensor? What if you VCDS that? Measuring block> group 4 shows it. Mine shows 31C right now when the ambient is 10C. Measure it now, then tomorrow AM when it's colder.

It ran (started and idled) better when I disconnected the throttle drive. Disconnecting just the temp sensor alone didn't make a difference.

I logged the intake temp sensor above at between 9-15C with the symptoms present. I certainly sounded reasonable given the low ambient.

[betyouaint]

Started and ran fine this morning. Looked like the problem was gone.

Arrived home tonight and back to square one. Starts and dies in 2 seconds. WTF?

Garage temp was 55C when I got home.

Does the ECU look at the O2 sensor at start-up or does it wait until after warm-up?