Big Issue, Need Help, Codes included

**passatkid** · 01-17-2009 02:25 PM

I have the following codes. Basically went to lunch car drove fine, came back car acts like it has no boost. Car starts, idles and drive fine it just has no boost, I don't have a boost gauge, it just is very sluggish. If I unplug the MAF it does not change at all, tried unplugging the N75 also no difference. Any thoughts, did my Ecu take a Crap. All other functions work, Cruise, ESP ABS. Really need some help.

VCDS Version: Release 805.1
Data version: 20081223

Saturday,17,January,2009,15:20:30:06561

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: WAULC68E22A225246 Mileage: 171390km/106496miles
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Address 01: Engine Labels: 06B-909-518-AMB.lbl
Part No SW: 8E0 909 518 F HW: 8E0 909 018
Component: 1.8L R4/5VT G 0001
Coding: 0016701
Shop #: WSC 63351 000 00000

8 Faults Found:

17978 - Engine Start Blocked by Immobilizer
P1570 - 008 - Implausible Signal - Intermittent
18062 - Please check DTC Memory of Instrument Cluster
P1654 - 004 - No Signal/Communication - Intermittent
17511 - Oxygen (Lambda) Sensor Heating; B1 S1: Performance too Low
P1103 - 008 - Implausible Signal - Intermittent
16523 - Oxygen (Lambda) Sensor B1 S2: Response too Slow
P0139 - 004 - No Signal/Communication - Intermittent
16712 - Knock Sensor 1 (G61): Signal too High
P0328 - 001 - Upper Limit Exceeded - Intermittent
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 002 - Lower Limit Exceeded - Intermittent
17956 - Boost Pressure Regulation Valve (N75): Open Circuit
P1548 - 004 - No Signal/Communication - Intermittent
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent
Readiness: 0000 0100

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Address 03: ABS Brakes Labels: 8E0-614-517.lbl
Part No: 8E0 614 517 A
Component: ABS/ESP allrad 1726
Coding: 04275
Shop #: WSC 06435

2 Faults Found:
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent
01826 - Sensor for Steering Angle (G85); Supply Voltage Terminal 30
35-10 - - - Intermittent

**old guy** · 01-17-2009 05:04 PM

The first thing I would suggest is to reset all codes and see what happens. Some of those codes were self inflicted. The Immobilizer and DTC memory codes should reset with no problems. The two oxygen sensor codes (one front, one rear) are a result of the heaters not working as fast as the ECU expected. Could be because of the colder air temperatures. If they were a serious issue you would have gotten a CEL. The knock sensor code should reset with no issues. the MAF and N75 codes were probably self inflicted from when you unplugged them and drove the car. The low voltage code should also reset without any issues. The 18265 error message code is simply stating that there was an issue recorded. I don't know what caused the G85 code, but it would have no effect on engine performance.

If you reset the codes and the problem persists with every thing else functioning properly I would suspect the N75. There are two things you can do to check this out. Depending upon which N75 you have you can check the impedance against these values:

058-906-283-C 20-30 ohm
058-906-283-F 25-35 ohm
034-906-283-H 25-45 ohm
034-906-283-J 20-40 ohm
034-906-283-K 20-40 ohm

When you electrically disconnected the N75 you eliminated the ECU's ability to dump boost pressure to the wastegate and consequently the full boost pressure was presented to the waste gate and limiting your manifold boost. You can disconnect the pressure line running from the N75 to the waste gate and see if the turbo is capable of building boost. Do this VERY carefully since you will be running unregulated boost. Just push the car enough to determine if the turbo can build boost and then back off. If you can build boost with the N75 pressure line disconnected I would suspect a defective N75.

Good luck!