Engine Check light

Tun · 11-07-20, 11:46 AM

Out for a little drive this morning and this light came on probably 3 times while accelerating but went off when I eased off. Anyone got any ideas what to check?

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BackintheFold · 13-07-20, 10:00 AM

An MB with less than 30K miles? Might be the lambda probe playing up!
Or engine knock sensor-how long has the fuel been in? was the most recent fill up low quality?

vagdream · 13-07-20, 02:45 PM

Quote:

Originally Posted by BackintheFold

Or engine knock sensor-how long has the fuel been in? was the most recent fill up low quality?

I seem to recall having to replace the knock sensor on my MB many years ago (at least 15) for a similar reason.

mikes2 · 13-07-20, 02:59 PM

You need to pull codes as the ecu will store it when that light flashes.

Fuse in the fuel pump relay to trigger the code sequence

Tun · 14-07-20, 06:53 AM

Thanks Mike, am I right in thinking the MB erasers the codes when you switch the ignition off or have I just imagined it?

Tun · 14-07-20, 07:43 AM

Quote:

Originally Posted by BackintheFold

An MB with less than 30K miles? Might be the lambda probe playing up!
Or engine knock sensor-how long has the fuel been in? was the most recent fill up low quality?

30K I wish, the milage is approximately 100,000 more than shown. The history and HPI reports suggest there was a problem with the dash. MOT in 1999 recorded 91644 next MOT in 2001 shows 3998.
The MB, or at least my MB, does not have a lambda sensor so I can rule that one out, and I always run super unleaded, it was last filled up about 6 weeks ago.

mikes2 · 14-07-20, 08:17 AM

Quote:

Originally Posted by Tun

Thanks Mike, am I right in thinking the MB erasers the codes when you switch the ignition off or have I just imagined it?

Think you might be right.

Best idea is to take it for a run and recreate the fault again. Pull the codes when you return without switching off.

Only time I had that when accelerating, it was the inlet air temp sender in the intercooler - wiring had come away

BackintheFold · 14-07-20, 09:15 AM

Phil Payne mentions the o2 sensor-in that when it dies (at around 30,000 miles) tape over or remove the warning light. I did find that odd but had no reason to question it.
EDIT This is for North American models only.

i can confirm that the codes are lost when you switch off.

Tun · 10-09-20, 06:48 AM

Update.
Finally managed to read the codes (remembered to do it before turning the engine off

), code 2142: engine knock sensor. New ones don't appear to be available so I replaced it with a Bosch 0 261 231 040 on advice from Pete Reeve. It is a bolt through one, fitting was as you would expect (PITA) due to it's cramped location. Only done a couple of short trips but no reoccurrance of the blinking light so hopefully all is well again.

vagdream · 10-09-20, 08:35 AM

Same solution ( ex P Reeve) 15 years ago as well!

13-07-20, 10:00 AM	#2
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	An MB with less than 30K miles? Might be the lambda probe playing up! Or engine knock sensor-how long has the fuel been in? was the most recent fill up low quality? Last edited by BackintheFold; 13-07-20 at 11:54 AM.

13-07-20, 02:59 PM	#4
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	You need to pull codes as the ecu will store it when that light flashes. Fuse in the fuel pump relay to trigger the code sequence __________________ 1991 90 quattro 20v sport 1991 90 quattro

14-07-20, 06:53 AM	#5
Tun Grown up member Classic Audi Club Member Join Date: May 2011 Location: Buxton Posts: 745	Thanks Mike, am I right in thinking the MB erasers the codes when you switch the ignition off or have I just imagined it? __________________ 1988 MB quattro 2012 S4 Avant

14-07-20, 09:15 AM	#8
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	Phil Payne mentions the o2 sensor-in that when it dies (at around 30,000 miles) tape over or remove the warning light. I did find that odd but had no reason to question it. EDIT This is for North American models only. i can confirm that the codes are lost when you switch off. Last edited by BackintheFold; 14-07-20 at 11:41 AM.

10-09-20, 06:48 AM	#9
Tun Grown up member Classic Audi Club Member Join Date: May 2011 Location: Buxton Posts: 745	Update. Finally managed to read the codes (remembered to do it before turning the engine off ), code 2142: engine knock sensor. New ones don't appear to be available so I replaced it with a Bosch 0 261 231 040 on advice from Pete Reeve. It is a bolt through one, fitting was as you would expect (PITA) due to it's cramped location. Only done a couple of short trips but no reoccurrance of the blinking light so hopefully all is well again. __________________ 1988 MB quattro 2012 S4 Avant Last edited by Tun; 10-09-20 at 10:19 AM.

10-09-20, 08:35 AM	#10
vagdream Grown up member Join Date: Jul 2015 Location: Llandudno Junction Posts: 165	Same solution ( ex P Reeve) 15 years ago as well!