Asr "limp Pedal" On A W 124 E 300 Twin Turbo

[Bryan Hawkins]

I would really welcome members opinions on the likely cause of intermittant ASR "limp pedal" on my 1990 E 300 W 124 twin turbo. The local MB dealers "definitely" identified the throttle switch as being at fault and replaced it for a mere £ 1200. The problem immediately re-ocurred. Next they said the wiring loom was definitely at fault - but couldnt actually provide any evidence. Finally, having given up on the wiring loom angle they have condemned the ECU (at £ 1500) again without being able to substantiate their opinion.
I am going to have the ECU removed and checked independently before I go any further.
ASR was a very rare extra in 1990, but I am hoping that someone out there can provide a lead. It is probably some stupid signal or impulse that is causing the problem.

Switching off the ignition and restarting the car resets the ASR until the next limp pedal failure

Help!

 

[television]

Could well be the over voltage relay, you do need a voltmeter to test, pin 30 is the input and will have 12 volts. the output on 87 should have 12volt but can drop if unit faulty. it is basics to start with a simple meter and be sure that every ECU is getting the correct voltage.

How far and how often does the fault happen, does it accure on a corner or bump

malcolm

 

[kth286]

Bryan

I am puzzled because as I undertsand, ASR was not a feature until the all electronic HFM 24 valve 320 engine (type 104). It's a drive-by-wire throttle control system.

Your year model is a late 12 valve 103 engine, or maybe an early 24 valve 3 litre without the all electronic control (it's just an electrically controlled mechanical fuel injection - no electrical fuel injectors).

It maybe you have ASD anti slip diff controlled by fluid ?

Am I making sense ?

Unless of course your car is special in some way because of the twin turbos ?

Your comments would be welcome.

Regards