rph
11-25-2013, 07:35 PM
It looks like the front acceleration sensor on my 1995 E34 540iLE is bad. It is a component of the Electronic Damping Control (EDC) similar to that fitted on Series 2 M5s, US and Canada M540i Sport, E31 8 series, and some E32 and E38 7-series (EDC III) of that era.
I say "it looks like" because I checked the voltages going into my EDC module under the rear seat, and there was almost zero voltage coming from that source. The other two acceleration sensors read 2.56v or thereabouts, which is what I expected at rest in the range 0-5v. So it could be some other wiring issue between that sensor and the module.
The part number is 37 14 1 181 291 -- not made anymore. It has allegedly been replaced by part number 37 14 1 179 832, but the old connector does not fit the replacement sensor exactly. I think the ground and positive terminals are reversed.
Anyway, since folks replace their EDC systems with coilovers, someone may have a good sensor lying dormant in their car, or may know of a car being parted out having EDC III. I am not ready to give up on my EDC just yet. The three acceleration sensors are identical: the front one is under the left front wheel arch (and liner) in Right Hand drive cars, there is one under the rear seat right near the module (in my E34 at least, but possibly not in an E32/38), and there is one in the trunk.
The serial number on the sensor itself is 1181291.
It is a bit of a pain removing the front sensor (not getting any younger), so I am waiting to locate a good one before diving under there again. I know I know, I could swap out one of my own good sensors to do a comparison. I thought of that. However in the end I reckon there's a good chance I will need a replacement. The front sensor is known to fail the most often for whatever reason, from what I can gather.
Not sure these sensors can be repaired. I haven't heard so.
Thanks,
Robert
I say "it looks like" because I checked the voltages going into my EDC module under the rear seat, and there was almost zero voltage coming from that source. The other two acceleration sensors read 2.56v or thereabouts, which is what I expected at rest in the range 0-5v. So it could be some other wiring issue between that sensor and the module.
The part number is 37 14 1 181 291 -- not made anymore. It has allegedly been replaced by part number 37 14 1 179 832, but the old connector does not fit the replacement sensor exactly. I think the ground and positive terminals are reversed.
Anyway, since folks replace their EDC systems with coilovers, someone may have a good sensor lying dormant in their car, or may know of a car being parted out having EDC III. I am not ready to give up on my EDC just yet. The three acceleration sensors are identical: the front one is under the left front wheel arch (and liner) in Right Hand drive cars, there is one under the rear seat right near the module (in my E34 at least, but possibly not in an E32/38), and there is one in the trunk.
The serial number on the sensor itself is 1181291.
It is a bit of a pain removing the front sensor (not getting any younger), so I am waiting to locate a good one before diving under there again. I know I know, I could swap out one of my own good sensors to do a comparison. I thought of that. However in the end I reckon there's a good chance I will need a replacement. The front sensor is known to fail the most often for whatever reason, from what I can gather.
Not sure these sensors can be repaired. I haven't heard so.
Thanks,
Robert