Hello Hugh,
Possibly electrical fault. However it could also be crud on the stop pin (at rest/zero position) - that's happened to my (old W202's) gauges. If crud then you'd obviously need to take out the cluster and remove the front plastic "glass" to be able to degrease the pin and end of the pointer with alcohol.
Richard
Possibly electrical fault. However it could also be crud on the stop pin (at rest/zero position) - that's happened to my (old W202's) gauges. If crud then you'd obviously need to take out the cluster and remove the front plastic "glass" to be able to degrease the pin and end of the pointer with alcohol.
Richard
Duff rev counter + ABS light stays on
Thanks - where does the rev counter pick up its' supply ?
What is the input voltage.
Just a few more questions............
ABS light is staying on irrespective of vehicle speed, I have a spare pair of sensors for the front - are there any on the back ?
Assuming the sensors are not at fault - what might the other fault(s) be ?
Thanks - where does the rev counter pick up its' supply ?
What is the input voltage.
Just a few more questions............
ABS light is staying on irrespective of vehicle speed, I have a spare pair of sensors for the front - are there any on the back ?
Assuming the sensors are not at fault - what might the other fault(s) be ?
Hugh,
I don't know much about the W124, but its probably similar in principle to my car. I'll go check the reference info on that and chat with brother who does have a 124 and post some info tomorrow. Perhaps (hopefully) some true expert on this model may respond in the mean time!
For now I would guess that:
1) ABS on the 124 senses the front wheels and probably the gearbox output shaft to the rear wheels, so could be a sensor attached to the gearbox. If it's not the sensors or either shorted or broken wires to sensors then of course the ABS black box unit could be u/s; but more likely and hopefully (as cheaper) to be broken wires or sensor, and not the ABS box itself.
2) Rev counter probably driven off an output from the engine management unit. Not sure if its a variable voltage or just a series of pulses, will check mine.
R.
I don't know much about the W124, but its probably similar in principle to my car. I'll go check the reference info on that and chat with brother who does have a 124 and post some info tomorrow. Perhaps (hopefully) some true expert on this model may respond in the mean time!
For now I would guess that:
1) ABS on the 124 senses the front wheels and probably the gearbox output shaft to the rear wheels, so could be a sensor attached to the gearbox. If it's not the sensors or either shorted or broken wires to sensors then of course the ABS black box unit could be u/s; but more likely and hopefully (as cheaper) to be broken wires or sensor, and not the ABS box itself.
2) Rev counter probably driven off an output from the engine management unit. Not sure if its a variable voltage or just a series of pulses, will check mine.
R.
MB_mark
New Member
Check (preferably by substituting with a known good one) the OVP relay. It's the tall relay with a fuse(s) in the top and located near the ECU behind the battery. This is usually the cause of the ABS light staying on, and it may (stress may) help the rev-counter, as bad OVP's can cause all sorts of weird electrical problems.
If you've jump started the car recently, this can sometimes blow the fuse in the top or even damage the relay. That's what it's designed to do after all, to protect the ECU from voltage surges (OVP = Over Voltage Protection)
Hope this help.
Best regards,
Mark.
Last edited:
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Hi,
If the ABS set-up is the same as my early C class 202 the rear ABS sensor is in the differential, secured there by a 6mm bolt.
If the ABS set-up is the same as my early C class 202 the rear ABS sensor is in the differential, secured there by a 6mm bolt.
