Hi,

I am newly registered on the forum, I am from Scotland and I have recently bought a 1996 N plate audi A4 4 door saloon, the problem I am having is that when I start her from cold she bursts into life no problem at all but after she has either been running for a few minutes either stationery or on the move once you stop the engine and then restart her she will turn and start but then cuts out on me. I have had the car on a diagnostic and the report read the following:-

"FAULT CODE 17978 (P1570) ENGINE CONTROL MODULE DISABLED. MAY ALSO NEED COOLANT SENSOR CODE 16500 (P0116) CIRCUIT RANGE SPORADIC."

I have just changed the coolant sensor and unfortunately this hasn't fixed the problem, one mechanic told me it could be the immobiliser on the car, another said that the car wouldn't start if it were the immobiliser causing the problem. I have disconnected the battery lead to see if this will reset the coolant sensor fault code as I was also told that once you replace the coolant sensor the vag com would have to be reconnected to erase the fault code so that the car would know that the new part has been fitted. I am really frustrated and don't know if this can be resolved and if I will need to call it a day with the car and move on and resell the car. Is there anybody out there that can help me and has anyone else encountered a problem like this and if so could they assist me in hopefully resolving the problem I am currently having with my audi A4, thankyou very much.

[>:][>:]

 

Welcome to Audi forums. Unfortunately it is 3 am in the US and most people on this forum are from the US so I am not too sure that anyone will respond for several more hours. I am not a computer code genius, hopefully someone else can give you more insight.

But the bentley manual says
17978 Control Module locked
I think the control module is related to the programming of the keys right? Did you recently have new keys cut for the car and not have them programmed? Or have them programmed by someone who was not Audi or VW? Or maybe the computer went psycho... either way, computers are only about a thousand dollars (US) and new keys with a reprogram on the whole thing is probably 1-200 dollars so that can't be worth scrapping the car right?

 

17978 = immobiliser activated ignition key chip problem

16500 = thermostat sticking/ lose wiring or bad connection

 

I had the p0116 or whatever code... doesn't that stand for ECT? change it. cheap, easy fix.
search the forums, i've posted this many time, so have others.

 

Classic symptom of a bad ECTS.

 

not when it applies to the immobiliser

 

Thank you very much for your replies, the mechanic I use on a regular basis suggested that the key could be an issue as it was not talking to to the ecu. But a specialist suggested that if the immobilser and the key was the fault that the car wouldn't even start. One mechanic suggested I have the fault code erased after fitting the coolant sensor and though this may help but again another has said that this will have no effect. As I have no experience whatsoever with the audi a4 I am totally lost to be honest and don't know what to do, one mechanic tells me one thing and another one tells me another and the money keeps ringing up and up.

I reconnected the battery lead not long ago and unfortunately this still didn't help the problem. The car itself is in good condition with a service history since new March 1996 (10 service stamps in the book) I don't know if the previous owner had new keys cut or had the keys programmed by anyone, do you think that this could be the problem and if I had a new key programmed to the car do you think this would solve the problem? has anyone else had this problem and resolved it with a new key programmed to the car? and if the fault codes were erased would this also solve the problems.

Thank you for your help.