Hello everyone, I own a 2003 Audi A6 3.0 with 131,000 miles on it. The gears displayed in the dashboard are blinking, and the car is in limpmode.

The car, will sometimes not engage in Reverse.

When turning the car on, and engaging the transmission from Park to Drive, there is a struggle when accelerating, and is overcome when enough gas is applied ( probably owards 2800 RPM) BUT this ONLY happens sometimes when freshly starting the car, and does not happen till the car is started again.

Car was in Drive at approximately 60 mph, I put it in Neutral, and back into Drive, The car did not engage. However, when i came to a complete stop, i was able to accelerate again.

I took it to a local Aamco, and had them print me a sheet displaying all the codes, the car is throwing. I am literally writing what they have written word for word:

1) DTC 18032 Mil request signal active ( check tcm for errors ) P1624 not a plausible signal.
2) 18339 Coolant fan ecu (P1931 Upper limit reached intermittent)
3) 17090 Transmission Range sensor Implausible signal P0706

After doing some research, I know the TCM seems to be the culprit for the limp mode, but I am hoping you could provide me with more insight, as i have very little experience with audis.

I am fairly mechanically savvy, and can do replacement by myself. If it is possible please send DITYG link.

Thanks Much!

 

Wilkommen to the forums!


Sounds like your transmission range sensor switch is starting to go. before you buy a replacement check the connection and make sure it is seated properly.

here is a writeup on how to get at the sensor
CHECK THIS OUT

good luck. let us know how it works out

-not an expert just an enthusiast

 

Thank you! Is there another link? the pictures on that guide are dead.

 

here is a different article

not exactly the same but should be close enough for you to get the general idea

transmission range switch

 

Just out of curiosity how do I know that the cause of limp mode is the sensor? or the ECM? What problems would need to occur to distinguish between the 2?

 

I have seen the same problem occur in other versions of the A6 and have posted a writeup about it at: Audi Repair Blog (Audi Reparatur Blog): Audi A6 and A8 Transmission Problems

One of the quick fix tactics I have used in the past is unplugging the Transmission Range Sensor and cleaning the connection. These plugs are known for corrosion especially if you live in a more humid climate.

 

I went to the link you provided, but i didnt see the write up you mentioned.

 

So i decided to take the car to the mechanic, and after diagnosing the vehicle for 3 days, he said he opened the transmission, and the oil was dirty and black. He recommended i sell the car, however i was wondering if anyone had any other suggestions? Is the transmission the cause of fail safe mode?

 

It is your range sensor as stated above. Might need to be cleaned. But your code told you what it is. Might need your tranny flushed too

 

I thought the tranny fluid is never to be replaced??