[V6-12v] Fwd: Codes

[Tom Christiansen]

Hi,

The EGR code (2411) is thrown if the ECU cannot detect a change in EGR passage temperature after it has ordered the EGR valve to open.

There are many things that may cause this:

1) Clogged, stuck, or defective EGR valve.
2) Clogged EGR passage in throttle body or exhaust header.
3) Malfunctioning EGR control solenoid valve (on the airbox under the MAF sensor).
4) Vacuum leak.
5) Faulty wiring.
6) Faulty EGR temp sensor.
7) Bad ECU.
8) Probably some other things I've forgotten.

The EGR valve can be checked by applying vacuum to is while the engine is running. You'll hear the RPM change when you open/close the EGR valve.

The EGR temp sensor can be tested using an ohmeter. Measure the resistance when the EGR valve is closed (engine running). Open the EGR valve as described above. Measure the resistance of the temp sensor. On my car (1994 90S), the resistance of the temp sensor changes by at least an order of magnitude (if not two). I forget the exact numbers, but seem to recall 250 kohm at cold, 20-ish kohm with the EGR valve open.

Bentley suggests measuring the coil resistance of the EGR solenoid valve. Even though mine was within specs, the solenoid was still defective.

I don't know about the 1111 code. Hopefully your ECU is OK...

Tom

On Thu, 11 Aug 2005, RGuzz wrote:

>
>
> Begin forwarded message:
>
>> From: RGuzz <rguzz at mindspring.com>
>> Date: Thu Aug 11, 2005  02:57:45 PM US/Eastern
>> To: v6-12v at audifans.com
>> Subject: Codes
>>
>> 95 A6 5 speed 137k miles...just did the EGR cleaning runs great but
>> codes still exist...check engine light came on and 2-4-1-1 was again
>> present (EGR system) then "cleared" that code and found
>> another...1-1-1-1. This was done by paper clip method as outlined
>> 12v.org. After cleaning EGR and manifold I disconnected the battery for
>> 30 minutes supposedly clearing old codes. Expecting, of course all to
>> be well. But the check engine light of course returned.
>> 1-1-1-1 indicates Control Module malfunction.
>> 2-4-1-1 indicates EGR system.
>> No, I didn't check the resistance to EGR temp sensor when the whole
>> thing was apart. Is that how one tests this temp sensor? It was a weird
>> looking thing. I did think about  just replacing it while I was there.
>> So, the questions are: why still the EGR and what do I do to look in to
>> the 1-1-1-1 code.
>> Lastly, is there a fuse to the ECU in this car? I believe the AAN
>> engine has a relay or fuse to the ECU that can be pulled thereby
>> "resetting" everything.
>> Thanks again.
>> Richard
>>
>
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