ABS Diagnostic Codes Help

[JamesArup]

Hi all, My ABS warning light is permanently on right now, and I'm trying to diagnose what the problem might be. The brakes all seem to work fine, but it's hard to identify if the ABS is actually kicking in. I've recently installed a Syvecs S7i too, so I am not sure what sort of affect this might have on the ABS lights. I have done the ABS diagnostics test by bridging the TC and E1 pins on the diagnostic port in the engine bay. I am getting the following error codes via the flashing ABS warning light: [B]Code 31 - On/Off/On[/B]: Malfunction of right front wheel speed sensor signal. Check speed sensor, sensor rotor, wiring harness and connector. [B]Code 32 - On/Off/On[/B]: Malfunction of left front wheel speed sensor signal. Check speed sensor, sensor rotor, wiring harness and connector. [B]Code 34 - On/Off/On[/B]: Malfunction of speed sensor signal for left rear wheel. Check speed sensor, sensor rotor, wiring harness and connector. [B]Code 36 - On/Off/On[/B]: Open in right front wheel or left rear speed sensor circuit. Check speed sensor, sensor rotor, wiring harness and connector. I'm am dubious as to whether these are actually correct, or whether there is just some electrical gremlin causing the ABS light to stay on (i.e. an MOT fail). The front and rear left ABS sensors should be fine, as they are both connected to the Syvecs, and they would show up as a fault on that. The standard Traction ECU has been removed as the Syvecs deals with all of that too, so I don't seem to have the TRAC On/Off light either to refer to. Has anyone else had this issue and know what it could be? If I can't fix it before the MOT, the bulb is coming out, but obviously I'd rather fix it :). I've also checked the fuses in the engine bay, the [B]ABS 1[/B] fuse is fine, but the [B]ABS 2[/B] fuse doesn't seem to be there! Is that normal? Thanks very much for any help, Cheers, J

[rider]

You can check the ABS sensors are OK by measuring the resistance from their loom plug connectors. The spec for this is in the workshop manual, I think it is something like 1.2k ohms plus or minus a little from my fading memory. Since you have all the codes logged you might want to do a battery disconnect hard reset and do a short drive to see which if all codes resurface.

[JamesArup]

Great, thanks for the suggestion! I'll have a look in the manual and see what those values are supposed to be, just to be sure. Also need to figure out where the loom plug connectors are :rolleyes: Will see if I can do it this afternoon. Thanks again, Cheers

[rider]

[quote name='JamesArup']Also need to figure out where the loom plug connectors are Cheers[/QUOTE] To access the rear sensor clips you need to remove the curved boot panels by the speakers. You do need to tease and slide those off more than pull otherwise some plastic positioning clips just snap off. The covers are held in place by a few screws so losing a clip or two isn't then end of life as we know it but obviously if you can avoid that its best to keep them intact. Once they are off you can follow the lead to the plug that sits just under the seat belt housing. Easy enough to disconnect with one hand in the small space using thumb and middle finger to tug whilst pushing down the plug clip with a free finger. The front sensor plugs are on a much shorter path from the sensor so easy to follow running along and from the upper control arm. If you do find there is no circuit then your sensor is dead (or wire cut) and it'll need to be replaced with a working sensor. Obtaining those is a bit of a task these days as there was only one front sensor still available as a new item last time I checked. You can fit any sensor 1993 - 2002 even though the codes changed with the facelift years.

[JamesArup]

Thanks Rider, very useful. Didn't have much of a chance yesterday, but took the car for a drive today, and now it's only showing Error Codes 34 and 36, the common denominator between those 2 codes is the Rear Left sensor, so I'm going to dig around now to see what I can find. That sensor should be plugged up to the Syvecs though, so I would have thought that would have thrown up an error if it wasn't working, but I'll check anyway. I think I know the panel you mean. Not the main big panel that actually houses the speakers, but the smaller one that sort of attaches to that and wraps around into the boot? I think I broke most of the clips on that many years ago when I was upgrading speaker wires, so that should be easy enough to get into! :D. I'll check now and see how it goes, thanks again! Cheers, J

[JamesArup]

Is this the fella here? .... [ATTACH]525687[/ATTACH]

[rider]

You've taken your pic from the other side to the picture I took so its hard to tell. This is the pic I took looking into the space. [URL="https://old.mkivsupra.net/vbb/attachment.php?attachmentid=222627&d=1506779705"]https://old.mkivsupra.net/vbb/attachment.php?attachmentid=222627&d=1506779705[/URL]

[JamesArup]

Great, thanks! I "think" that's the one that I highlighted in my photo. It's the only grey one in there as far as I can tell. I'm out of the country now, but will give it a check once I'm back again ... if I'm allowed in!