AndyP
Member
I have a very intermittent starting problem on my TDi75, oddly this seems only from cold, but that could be coincidence as it happens so infrequently. Totally randomly and days/weeks/months apart it fails to start, engine turns over well, fires immediately and stops after a second - probably one firing stroke per cylinder. Excactly the same symptoms as if the imobiliser is preventing the engine from starting - I can prove this with my spare uncoded key. The difference then is that the EML light is on and the glow plug light flashes. With my coded key all lights are normal, but it doesn't continue running. It will turn over for 10 seconds, no difference. Remove key, lock/unlock car, try again, walk away, come back, same etc., then randomly, could be 1 minute later or 1 hour later absolutely fine, starts immediately. Initially, I thought this was a fueling problem but now I think it's immobiliser related.
I checked for ECU codes with Torque and found none. I dug out the laptop with VAGcom and there is Camshaft Position Sensor (19464) - (shame it doesn't display how many or the time of the fault). However, this symptom is different and I think occasional Camshaft sensor faults are "normal", plus I replaced it last year anyway.
There is also a 17978 which my shareware version doesn't decode but I just had to Google and I get:
17978 - Engine Start Blocked by Immobilizer
In case of Engine Starting Issues please make sure that you are really experience an Immobilizer related Problem! ... May be stored in Combination with 01176 - Key: Signal too Low in Immobilizer Control Module.
Eureka ! So this probably coincides with me testing the theory with the uncoded key. Now I have to wait for it to do it again to see if I get a fault from the normal key. I'm considering having the imobiliser disabled, presumably that needs the fully featured VAGcom? @timmus @2work - any thoughts?
I checked for ECU codes with Torque and found none. I dug out the laptop with VAGcom and there is Camshaft Position Sensor (19464) - (shame it doesn't display how many or the time of the fault). However, this symptom is different and I think occasional Camshaft sensor faults are "normal", plus I replaced it last year anyway.
There is also a 17978 which my shareware version doesn't decode but I just had to Google and I get:
17978 - Engine Start Blocked by Immobilizer
In case of Engine Starting Issues please make sure that you are really experience an Immobilizer related Problem! ... May be stored in Combination with 01176 - Key: Signal too Low in Immobilizer Control Module.
Eureka ! So this probably coincides with me testing the theory with the uncoded key. Now I have to wait for it to do it again to see if I get a fault from the normal key. I'm considering having the imobiliser disabled, presumably that needs the fully featured VAGcom? @timmus @2work - any thoughts?