sensor coolant code

**tommy782** · 08-03-2008 08:16 PM

my fans on my a4 1.8t 2003 doesn't work (2) and I have a coolant sensor code (G83) and I just want to know if this is the upper or the lower sensor.

thx

**dougyfresh** · 08-04-2008 07:18 AM

what is the five digit fault code? G83 doesn't help me.

For example: "16496/P0112 - Intake Air Temperature (IAT) Sensor 1 Circuit (G42): Low Input"

**tommy782** · 08-04-2008 05:25 PM

the code is

17698 - Coolant Temp Sensor at Radiator Outlet (G83): Signal too Small
P1290 - 002 - Lower Limit Exceeded

thx!

**HIERLEVELZ** · 08-04-2008 08:38 PM

Funny ive been getting the same code and i swapped out the sensor on the lower radiator hose(grey 2-pin) only today. Im assuming thats the outlet. The green 4pin i swapped out when I first got the car so i cant imagine thats the cluprit. Ill have to scan the car again and see if the code comes back.

**tommy782** · 08-05-2008 10:21 AM

ok give me somes news because I don't like this when I see the temp gage at 130!!!

**dougyfresh** · 08-07-2008 05:38 AM

Originally Posted by tommy782

the code is

17698 - Coolant Temp Sensor at Radiator Outlet (G83): Signal too Small
P1290 - 002 - Lower Limit Exceeded

thx!

Have you checked the sensor at the lower radiator hose? I believe that is where this signal is coming from. If you are going to replace it also pick up a new sensor for the rear coolant flange in the back of that head. That one typically takes a shit. When it does, the car runs super rich. Both replacements should be green in color.

proper sensor: http://www.purems.com/products/product.php/II=1472

sensor clip (in case it breaks on you): http://www.purems.com/products/product.php/II=1491

o-ring seal: http://www.purems.com/products/product.php/II=2192

(You don't need the clip and seal if your original stuff is okay)

**Affinitive** · 08-07-2008 10:23 AM

The radialtor fan switch should be a two pin grey sensor. Have never had to replace one yet. Replaced countless green sensors though. Them sensors are a dealer only type of part to avoid problems later.

Though, based on what you're saying and my experience with AMB 1.8T's, I would suspect the Thermostat to be faulty. Very commonly see those T-stats causing the coolant to circulate mainly through the heater core and hardly any through the radiator. Unfortunately, the t-stats in AMB 1.8T's are the biggest joke ever.
C

**dougyfresh** · 08-07-2008 10:54 AM

Originally Posted by Affinitive

The radialtor fan switch should be a two pin grey sensor. Have never had to replace one yet. Replaced countless green sensors though. Them sensors are a dealer only type of part to avoid problems later.

Though, based on what you're saying and my experience with AMB 1.8T's, I would suspect the Thermostat to be faulty. Very commonly see those T-stats causing the coolant to circulate mainly through the heater core and hardly any through the radiator. Unfortunately, the t-stats in AMB 1.8T's are the biggest joke ever.
C

Have you had any luck with retrofitting an older (2001-ish) style thermostat onto an AMB? My only concern is the ECU freaking out when it doesn't have a signal from that heating element on the AMB thermostat. I've been thinking of installing the older style system on my engine.

**Affinitive** · 08-07-2008 11:44 AM

Never tried or thought of trying. The little heater element in the stat can be unplugged and not set faults. Like BMW, the idea is that the ecm can force the stat all the way open when extra cooling is required by applying current to stat. As for converting.......I would think it to be quite a project as it would require new lower rad hose for the regular stat housing, different coolant pipe on top of intake and coolant flange and different heater core plumbing. I think the best bet would be to convert all the cooling system stuff to that of an AWM engine. I'm sure it could be done as long as the stat housing fits. The concern with the stat housing being that the AMB has a totally different alternator and bracket mounting to the engine than all the other 1.8's. So I'm not sure if a regular housing would clear the Alternator/bracket assembly. HHHMMM, now I'm curious.
The AMB is great and all but it kinda sucks in the fact that it's the most unique 1.8 out of all of them.

C

**tommy782** · 08-17-2008 08:48 AM

I finally found my problem. first I change my coolant sensor on the radiator hose. the code doesn't appear on my computer but the fans don't start!!!.I search and I found a wire on the module. the wire was cut and the contact doesn't pass. I weld this wire and the fans work great!!!. I save 250$$!

ThX AuDiZiNe!!

**AudiOso** · 08-17-2008 10:24 AM

I would check with your dealer about the rear sensor if it is bad. Audi covered mine under an extended warranty program due to problems with the original sensors that were installed at the time of manufacture. It's worth looking into.

**dougyfresh** · 08-17-2008 11:10 AM

Originally Posted by Affinitive

Never tried or thought of trying. The little heater element in the stat can be unplugged and not set faults. Like BMW, the idea is that the ecm can force the stat all the way open when extra cooling is required by applying current to stat. As for converting.......I would think it to be quite a project as it would require new lower rad hose for the regular stat housing, different coolant pipe on top of intake and coolant flange and different heater core plumbing. I think the best bet would be to convert all the cooling system stuff to that of an AWM engine. I'm sure it could be done as long as the stat housing fits. The concern with the stat housing being that the AMB has a totally different alternator and bracket mounting to the engine than all the other 1.8's. So I'm not sure if a regular housing would clear the Alternator/bracket assembly. HHHMMM, now I'm curious.
The AMB is great and all but it kinda sucks in the fact that it's the most unique 1.8 out of all of them.

C

What I highlighted in bold is exactly what I've been trying to figure out. Then again, I guess I could have unplugged mine and checked with VAG-Com.

I'll have to look over my friend's AWM engine a bit more closely. I didn't realize the upper hard line was different. I knew I'd need a new lower radiator hose and have to get that hard line that comes out the back of the water pump region on the block... And retrofit the heater core lines. etc.

Before doing all of this I am going to see if we can tweak the map within the ECU... All in an attempt to get the engine to run a bit cooler, to make more power safely. It'll come down to whether or not my tuner wants to do this. Its all theories in my head right now.