andrew burnett
New Member
- Joined
- Jun 14, 2015
- Messages
- 2
- Car
- e220 cabriolet. CLS 350cdi.
Help
I have a W124 E220 Cabriolet with a permanent ABS warning light on the dashboard.
I've read all the associated threads I can find and done a lot of checking/testing.
The basic facts are as follows:-
The ABS warning light comes on when the ignition is swiched on and doesn't go off at all.
I've tested both the control relays in the hydraulic unit, including the diode and they are fine.
The over voltage protection relay and associated fuse test ok, (although tick over is fine so I didn't suspect a fault here anyway).
The battery is good and charging well, (12.5v normal and 14v ish under charge).
I have disconnected the alternator to make sure an unusual waveform/spikes were not upsetting the ABS ECU
I have checked both front wheel sensors and the rear sensor at the ecu plug for resistance and insulation, all of which are in spec.
I've checked the electrical continuity of the solenoid valves at the ecu plug which appears ok.
I have changes the ABS ECU, (albeit for a used one off ebay).
Finally if I manually operate the solenoid valve relay the ABS LIght goes out which should rule out a faulty dahboard.
I'm not sure if a specialist or dealer could identify the problem using a code reader. Any ideas or suggestions would be much appreciated thanks.
I have a W124 E220 Cabriolet with a permanent ABS warning light on the dashboard.
I've read all the associated threads I can find and done a lot of checking/testing.
The basic facts are as follows:-
The ABS warning light comes on when the ignition is swiched on and doesn't go off at all.
I've tested both the control relays in the hydraulic unit, including the diode and they are fine.
The over voltage protection relay and associated fuse test ok, (although tick over is fine so I didn't suspect a fault here anyway).
The battery is good and charging well, (12.5v normal and 14v ish under charge).
I have disconnected the alternator to make sure an unusual waveform/spikes were not upsetting the ABS ECU
I have checked both front wheel sensors and the rear sensor at the ecu plug for resistance and insulation, all of which are in spec.
I've checked the electrical continuity of the solenoid valves at the ecu plug which appears ok.
I have changes the ABS ECU, (albeit for a used one off ebay).
Finally if I manually operate the solenoid valve relay the ABS LIght goes out which should rule out a faulty dahboard.
I'm not sure if a specialist or dealer could identify the problem using a code reader. Any ideas or suggestions would be much appreciated thanks.
