2007 A4 Never ending check engine light and limp mode

[stylesx]

This is driving me crazy, my car seems to have an intermittent issue which results in blips in the throttle causing check engine lights and not all the time but at times I get ESP and EPC lights on which causes the car to go into limp mode or safe mode. This limp mode basically allows the vehicle to be driven but with weak gas response so if I was to slam the gas pedal down the car will just gradually pick up speed. Below I have kept a CEL log and what work was done. After the gas pedal replacement now they want to do a FULL engine harness replacement at $4k for parts only which is ridiculous. Any assistance would be greatly appreciate or else I would have to take my bicycle out of storage :) its hard to put baby seats on it...



Jan 5,2016
00769
07172
00768
00773

Feb 24, 2016
00592

March 11, 2016
00769
04641
P0301
P0121

** - MAP sensor (cleaned 4/28/2016)

May 2, 2016
P0221
P0121

May 30, 2016
P0221

July 4, 2016
P0121

** Throttle position sensor (gas pedal) was change on July 21

Aug 29, 2016
P0068 x 2 f

Sep 11, 2016
P0121
P0068

[Charles.waite]

P0221, P0121, P0068 all point toward the throttle body being bad or the wiring to the throttle body being bad. You don't need a new engine harness just a few new wires. Also it seems their MAP sensor cleaning caused more problems (hence the P0068 appearing after they "cleaned" it). I would replace it with a new one.

Also I wouldn't take the car to the shop any longer. It sounds like they don't care and don't want to deal with a pesky electrical problem that they can't, or are unwilling to, diagnose.

I'm sure someone can help out a bit more, I've never dealt with engine bay electrical issues before so I'm a bit of a noob in that department. Also, do you mind specifying what engine? when in doubt we all assume 2.0t but you could be a 3.2 I guess.

[Theiceman]

also is the car stock ? or has it been "tuned" this is valuable info.

[stylesx]

P0221, P0121, P0068 all point toward the throttle body being bad or the wiring to the throttle body being bad. You don't need a new engine harness just a few new wires. Also it seems their MAP sensor cleaning caused more problems (hence the P0068 appearing after they "cleaned" it). I would replace it with a new one.

Also I wouldn't take the car to the shop any longer. It sounds like they don't care and don't want to deal with a pesky electrical problem that they can't, or are unwilling to, diagnose.

I'm sure someone can help out a bit more, I've never dealt with engine bay electrical issues before so I'm a bit of a noob in that department. Also, do you mind specifying what engine? when in doubt we all assume 2.0t but you could be a 3.2 I guess.

Thanks for taking the time to reply, yes forgot to mention that its a 3.2

[stylesx]

also is the car stock ? or has it been "tuned" this is valuable info.

Completely stock besides one sticker on the back window and two baby seats :), but all joking aside the car is completely stock

[reno808]

Do you have a vag com? if you do not i would suggest in investing in one. I would start with what Charles said. Cleaning the MAP senor will not do anything at all, so just replace that its not expensive and easy to do. Check the wiring on the TB and wiggle it to see if the epc and traction control light does on. If it does not go on then then i would buy a TB make sure its Audi and not the other brand. I have had many issues with the other brands, i know many other ppl have had luck with the others, but in your case i would just go with the Audi dealer parts as you have many issues. Do not replace the harness and do not go to that shop anymore

[stylesx]

Do you have a vag com? if you do not i would suggest in investing in one. I would start with what Charles said. Cleaning the MAP senor will not do anything at all, so just replace that its not expensive and easy to do. Check the wiring on the TB and wiggle it to see if the epc and traction control light does on. If it does not go on then then i would buy a TB make sure its Audi and not the other brand. I have had many issues with the other brands, i know many other ppl have had luck with the others, but in your case i would just go with the Audi dealer parts as you have many issues. Do not replace the harness and do not go to that shop anymore

I think I will try the replacement of the MAP and they called me back since my car is still there and now suggesting a smaller overlay which connects to the throttle body for $130 which seems more doable so I told them to go ahead with that one, hopefully it does something.

[reno808]

I think I will try the replacement of the MAP and they called me back since my car is still there and now suggesting a smaller overlay which connects to the throttle body for $130 which seems more doable so I told them to go ahead with that one, hopefully it does something.

what did they mean by overlay? seems like shop has no clue to what they are doing. Were you located?

[stylesx]

what did they mean by overlay? seems like shop has no clue to what they are doing. Were you located?

What they meant is that they will cut the portion of the wiring harness to the throttle body and connect a new one with a new connector at the end. I am located in the Toronto area, Canada.

Something along the lines on this, and yes i know that is a VW

http://forums.vwvortex.com/showthrea...harness-repair

[reno808]

What they meant is that they will cut the portion of the wiring harness to the throttle body and connect a new one with a new connector at the end. I am located in the Toronto area, Canada.

Something along the lines on this, and yes i know that is a VW

http://forums.vwvortex.com/showthrea...harness-repair

makes sense. Did they test the TB first? Perhaps a ziner on here can help you. i would if you were in the tri-state area.

[stylesx]

makes sense. Did they test the TB first? Perhaps a ziner on here can help you. i would if you were in the tri-state area.

Here are there notes from the Audi Tech. One thing I should have mentioned from the beginning is that I had another mechanic look at this issue a while back and they replaced the wiring that Audi is trying to replace again now, after myself reviewing their work seems like they may have used a part for the connector that is not from Audi. Audi is now suggesting to redo their work with the correct part on step 10, 11 and 12.



GUEST CONCERN VEFIFIED, ENGINE LIGHT IS ON. GFF SCAN FOUND |

| 2. INTERMITTANT CYL 3 MISFIRE. PERFORMED ROAD TEST WHILE |

| 3. READING VALUE BLOCKS, NO MISFIRES WERE RECORDED. |

| 4. OTHER FAULTS WERE FOUND P1564 (THROTTLE VALVE CONTROL UNIT, |

| 5. INSUFFICENT VOLTAGE, AND P1579 (THROTTLE VALVE ADAPTATION |

| 6. NOT INITIATED). CHECKED WIRING FROM THROTTLE BODY TO ECM, |

| 7. WIRING IS OKAT. CHECKED WIRING FROM ACCELERATOR PEDAL TO ECM |

| 8. , WIRING IS OKAT. CHECKED RESISTANCE OF THROTTLE BODY, |

| 9. WITHIN SPEC. CHECKED SUPPLY VOLTAGE TO THROTTLE BODY, WITHIN |

|10. SPEC. WIRING REPAIR HAS ALREADY BEEN ATEMPTED AT THE THROTTL |

|11. E BODY, THIS REPAIR WAS FOUND TO BE NOT TO AUDI OEM STANDARD |

|12. S. THIS MAY BE CUASE FOR CONCERN, TO CORRECT ISSUE THE |

|13. ENGINE HARNESS WIL NEED TO BE REPLACED. AN OVERLAY CAN BE |

|14. ATTEMPTED FROM THE THROTTLE BODY TO THE ECM TO CORRECT |

|15. FAULTY WIRE REPAIR, BUT THIS WILL NOT GARENTEE THIS WILL |

|16. CORRECT ISSUE COMPLETELY AS THERE WILL BE BUT CONNECTORS ON |

|17. ALL WIRES WHICH MAY BECOME FAULTY AT A LATER DATE.

[stylesx]

Is there anyone in Oakville Ontario that would be able to perform a throttle body adaptation with vagcom. The issue is still occurring even after I changed the wiring hardness and pedal and spent a crap load of mechanic hours. Yes it's 2017 Aug and still going on.


Thank you

[supple]

That's crazy. I've been seeing similar issues during crank, may sputter out or it will have a real bad idle. I just turn it off and recrank with a little bit of gas and it starts fine. I feel like if I wiggle the connectors and make sure they're on tight, to the throttle body it helps keep this from happening. Also seems to occur during periods when there's more moisture in the air....

Let me know if you even figure this out. I got a new throttle body last winter and the next things I wanted to look at are the wiring harness and maybe N75 as a guess.