My car is a 2000 A6 4.2l Quattro with 115,000 miles. Drove home fine at night, started up and backed out of driveway in morning fine, put in drive and nothing happened. Used Ross-Tech VAG scan tool and found VAG DTC 17114/P0730 - Transmission range/ratio monitoring wrong transmission ratio. No other codes up on car.

Potential causes: ATF level wrong or dirty, changed filter and ATF, brown in color, slightly burnt smell, level appeared OK. Other causes: Transmission input speed sensor G182 faulty or transmission output speed sensor G195 faulty. Performed electrical test on both as per repair manual, both within resistance spec.
Other cause: wrong or incorrectly coded TCM. This was not changed so assume this to be correct. And last potential cause, brake slippage/malfunction or solenoid vavle diry/malfunction. Tested solenoid valves electrically per manual and OK, but don't know how to check if dirty. Also don't know how to check brake slippage inside transmission without a complete teardown.

Cleared code, but no change on transmission. At 1400 rpm car goes back into limp mode.

Can the TCM (transmission control module) be bad, even though there are several codes to indicate if this is the cause, and none of those codes are present? It is active and I don't have any water damage in the area.

Tearing down the tranny for brake slippage would seem to be the last resort, and most expensive.

Thank you so much for troubleshooting this with me, I have spent several days on it and not see what is wrong.

EclipseJEM

 

Looks like the transmission life came to and end...
Make sure the oil level is correct!
Even on a limp mode the car should move forward - is this your case?
I have found a manual procedure to get off the limp mode - check audiforums.com for my posts.
GL