A8q D2 '98 - Transmission/ECU/TCM/Airflow Sensor related problem
#1
A8q D2 '98 - Transmission/ECU/TCM/Airflow Sensor related problem
Hi ! First Post.
3-4 months ago I've experienced this problem - when starting the car all the lights for the gears are on and the tranny is in limp mode ("limp mode" expression discovered in this forum). to solve the problem I shut the engine and start it back on and the problem was solved. after a while the problem became more frequent. i changed the tranny liquid and filter. the problem was solved for about 3-4 weeks.
now these days i have more complex related problem -> the switching off and back off works only for 10-30 sec (enough to achieve speed of 30-40 Km/h) and enters the limp mode again. it never entered that mode while driving before. to drive 5-6 km i need to switch off and on the engine about 10 times.
today i bought a VAG-COM cable and did some diagnostics.
I've received these error codes :
Engine:
00553 - Mass Air Flow Sensor (G70)
27-00 - Implausible Signal
00550 - Start of Injection Regulation
17-10 - Control Difference - Intermittent
Transmission:
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent
Everything else if fine.
As i read the forum about related problems i understood that it might be related to defective ECU, TCM, Relay for the ECU, etc.
I read also that the air flow sensor implausible might be related
also to the ECU. Also the indicator for the brakes shows from time to time on the dash but the brakes are OK.
I also cleaned the Air Flow sensor due to previous suggestion that the problem is from there (it was clean enough but I cleaned it anyway)
Thanks in advance for Your help !
How to determine the defective part or what action to perform ?
Thanks in advance for Your help !
3-4 months ago I've experienced this problem - when starting the car all the lights for the gears are on and the tranny is in limp mode ("limp mode" expression discovered in this forum). to solve the problem I shut the engine and start it back on and the problem was solved. after a while the problem became more frequent. i changed the tranny liquid and filter. the problem was solved for about 3-4 weeks.
now these days i have more complex related problem -> the switching off and back off works only for 10-30 sec (enough to achieve speed of 30-40 Km/h) and enters the limp mode again. it never entered that mode while driving before. to drive 5-6 km i need to switch off and on the engine about 10 times.
today i bought a VAG-COM cable and did some diagnostics.
I've received these error codes :
Engine:
00553 - Mass Air Flow Sensor (G70)
27-00 - Implausible Signal
00550 - Start of Injection Regulation
17-10 - Control Difference - Intermittent
Transmission:
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent
Everything else if fine.
As i read the forum about related problems i understood that it might be related to defective ECU, TCM, Relay for the ECU, etc.
I read also that the air flow sensor implausible might be related
also to the ECU. Also the indicator for the brakes shows from time to time on the dash but the brakes are OK.
I also cleaned the Air Flow sensor due to previous suggestion that the problem is from there (it was clean enough but I cleaned it anyway)
Thanks in advance for Your help !
How to determine the defective part or what action to perform ?
Thanks in advance for Your help !
#3
:)
Ok. No suggestions. At least can anyone tell me where to find the power relay for the ECU, I read somewhere that it may be the cause of the problem ant that's why the ECU sends error code to the TCU/TCM? Thanks !
#4
You might try some other forums, not much action here anymore. In the meantime I'd check the battery, battery cables, grounds, and see if there is water standing in the cowl due to plugged drains. That can affect the TCU.
#5
Recently had similar issues like your car. Narrowed it down to a dead ECU and moisture damaged harness. Also discovered the relay box in the passenger footwell was soaked - the power relay is located here also, by the way. Replaced the ECU & harness with used units from Shokan & cleaned/dried out the relay box & relays & other connections and now car is good to go. Be sure to let everything dry out THOROUGHLY before you put power back through them. Good luck!
#6
Old Audi Owner
Join Date: Mar 2009
Location: Minnesota
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
The limp mode portion of my trans issues was directly related to a dead MAF. It looked perfect bit the signal was intermittent. Replaced with aknown good unit and limp mode was gone.
#7
I've changed the MAF - no change .
i've had problem yesterday with IP - car wont start - now is ok (they changed something in the electronics of the pump), however now i've read some more forums and found out that 550 error comes from wrong regulation of the IP and from there the power problems - maybe also reflecting to the ECU and from there the Error Message from ECU(18265) to TCU/TCM - and from there the limp mode engagement.
Can anyone tell me about the 18265 error code - what may cause it ?
PS I've changed the 219 Relay - of the ECU, previously suggested as problematic, but no change from it.
ok ! Thanks in advance !
i've had problem yesterday with IP - car wont start - now is ok (they changed something in the electronics of the pump), however now i've read some more forums and found out that 550 error comes from wrong regulation of the IP and from there the power problems - maybe also reflecting to the ECU and from there the Error Message from ECU(18265) to TCU/TCM - and from there the limp mode engagement.
Can anyone tell me about the 18265 error code - what may cause it ?
PS I've changed the 219 Relay - of the ECU, previously suggested as problematic, but no change from it.
ok ! Thanks in advance !
Thread
Thread Starter
Forum
Replies
Last Post