ukDIESELdriver

Hey guys,

I recently bought an A8 4.2 QS 40V and recently on long distances the car does not start up properly. My dad had a friend check it out with a vag com...he jotted down a few things: MAF sensor G70 p0102 and coolant temperature sensor p0116 and fuel relay pump.

Can anyone make head or tail out of this, thanks

PaulW

"does not start up properly"

Have no idea what that means.

Get the exact codes, save them in a word document, then clear them.

Operate the car again and see if it does not start up properly, and if so, pull codes and post what they are.

Always Overcharged

The other fault p0102 translates to 16486
see below [scroll down]
good luck

V.A.G 1551 print-out
Possible causes of fault
Possible effects
Fault remedy

16486
Air mass meter -G70





Signal too small
- Open circuit in wiring between air mass meter and engine control unit -J220
- Limp-home mode (substitute value from throttle angle and engine speed), therefore no noticeable effect on driveability
- Eliminate short circuit or open circuit in wiring
=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations binder

16487
Air mass meter -G70
- Air mass meter defective

- Check air mass meter => Page 24-93


Signal too large
- Short circuit to positive or earth in signal wire to engine control unit -J220





- Signal input in engine control unit defective (control unit defective)

- Renew engine control unit =>Page 24

ttuling

They fail -- sometimes intermittently -- with some regularity and are easy to change. The sensor is in the same housing but electrically independent of the used by the gauge. Use VAG-COM to see whether the engine computer reads a plausible coolant temperature when the starting difficulties occur.

But that's speculation. The codes you mention do not point to a problem so common as to allow normal troubleshooting, i.e. with the service manual and diagnostic tools, to be bypassed.

Tom