a4 idle problem

[lucianus]

when i start it, it idles at around 1100 rpms for about 5 mins then it drops at 800-900 rpms like its supposed to. sometimes like once a week it doesn't start on the first try. i have scanned it with vag-com and i get those errors:

17972 - Throttle Actuator (J338): Under-Voltage during Basic Setting
P1564 - 35-10 - - - Intermittent
17967 - Throttle Valve Control part (J338): Fault in basic settings
P1559 - 35-10 - - - Intermittent
00561 - Mixture Adaptation
15-10 - Adaptation Limit (Add) Not Reached - Intermittent
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - - Intermittent
16502 - Engine Coolant Temp. Sensor (G62): Signal too High
P0118 - 35-10 - - - Intermittent

thanx alot :beerchug:

[bearthebruce]

How old is the battery? Is it possible that the battery is not holding charge on the cooler nights?

I could suggest action for all but the Immobilizer - but that one bothers me and leads me to think this is voltage related. Did you scan any other modules? Did they complain of voltage issues?

[lucianus]

i don't know about the battery. i think it's old. it could be the battery. i can't scan other modules because i have a crap vag-com cable. but i can't think of the battery messing up with the throttle... and also when the rpms drop below 500-600 the air con turns itself off... i suppose that is normal due to lack of power at low rpms?
thanx alot for your help