No Accelerator pedal response - engine sits at 1200rpm

[themuttons]

Hi Folks, looking for some help. I have started to have problem of no accelerator pedal response, you can push to the floor and no acceleration, the engine sits at 1200rpm and the coil light begins to flash.

If the car is switched off and left for a bit it can come good eventually.

I Have had the vag com on it and indicates throttle position sensor fault, and then MAF ground fault.

The throttle pedal / position sensor assembly was changed yesterday but while driving home fault came back, but then came good after coasting for a little bit at 1200 rpm!

The MAF has recently been changed.
While searching for answers I have read a few posts about ECU getting fried, and so I am a little concerned!!

Any help appreciated

Audi A4 B5, 2000, 1.9tdi 115 BHP, engine code AJM.

[themuttons]

Quick update, fault codes as follows;

18039 P1631 Accelera.Pedal Pos.Sensor 1 Signal too High
18040 P1632 Accelera.Pedal Pos.Sensor 1 Power Supply Malfunction

[kenney]

since the unit is new we can assume it is ok,have you adjusted it??you can also check its function in measured value blocks 08 and display group 002

[themuttons]

No adjustments as far as I know, (didn't put it in myself), will have a look at the values as suggested.

[themuttons]

Hi Folks problem still there, have had all wiring and grounds checked around ECU, Dash, bulkhead etc. Had found some water collecting in battery tray / bulkhead but nothing conclusive. Is good for a bit and then will fail to teh 1200 rpm.

Fault codes

18039 - Accel position sensor signal to high
17553 - Mass airflow sensor G70 short to B+

Any help please - is wrecking my head!

[Crasher]

I have had this when water gets into the plugs under the ECU.

[themuttons]

Thanks for that crasher, all plugs have been removed and checked relating to the two inputs from the MAF and Pedal, there was some water in the area, but maybe it was not all cleared. Did you just dry it all out?

Could there be damage to the ECU. I was also thinking of changing the MAF again, as this only started a week or so after changing that - it wasnot an OEM part that went in so thinking this may be related to that.

Thanks again.

[Crasher]

I see this problem quite a lot on A4, Passat and Superb, there is often damage to the pins which needs careful cleaning. If you look very closely at one of the pins in the orange plug you will see it is green and fury. You should only ever use an Air Mass Meter (MAF) bought from a VW dealer.

[themuttons]

Thanks for the info. I think the I've uncovered the route of the problem - only buy genuine Audi / VW parts!!
Wiring and plugs checked out.
With fault light on and engine sitting at 1200 RPM, disconnected MAF and light goes out, engine returns to normal idle, connected old MAF and engine still ok. Reconnected the 'New' MAF and fault returns.
Lesson learnt don't try and save 50 quid with non OEM parts! Still trying to figure how this affects the accelerator pedal, but happy problem seems to be solved, will be putting in Bosch MAF this evening.

Thanks for the help.