I've had an issue since purchasing the car with the abs I'm going to try and work though this winter. I'm looking for procedures I can do without having the J35890 tester (which I have yet to find at a reasonable price). Local shops have not been successful in finding one still having that tool.

Anyone know of a good set of diagnostic procedures for the 86 (early) ABS that doesn't require the J35890 tester?

Here's what's happening: ABS light comes on as soon as the key is turned on and stays on continuously. Occasionally if stop the engine and restart the car the light goes out and ABS seems to work, but only that way otherwise the lights on solid.

I've read the FSM and I've checked the brake and gauge fuses listed in 5E-4, both are good and the connectors are tight. Stop/Hazard lights work. All the gauges and their fuse look good. Checked the fusible links, all good. Relays on the pump and cables are tight. Fluid level is good. Pretty much done the quick stuff listed in the FSM and so far have not found the issue.

Being it occasionally works, I'm leaning towards it being one of the 2 relays on the pump failing most of the time operating correctly. I assume you can simply remove them and rig up a quick power test to insure they're cycling and that should be enough.

I haven't found anything on the abs sensors themselves. If they just ohm out the ABS sensors at the wheels using a DVM at the connector near the wheel, is that sufficient if there is continuity or is there a particular resistance value that must be present for them to be good?

Does this make sense or does someone have a better way of diagnosing the abs system, again without that tool unless I luck into one.

Thanks.

 

Have you tried pulling the sensors and cleaning them? Look for grease, dirt and magnetically attracted particles from the semi-met pads. Also on the reluctor wheel on the hub can get rusty and dirty also... I would check all 4 to make sure all the basics are covered. The ABS lite on mine was on and the cure was simply a good cleaning of the sensors.

 

I did the rears but not the fronts. I'll add that to the list. Thanks.

 

Did you find problems yet? i just cleaned my rears today, still need to do the front, a relay clicks when I turn the key on but the pump dont circulate. I know someone with a tester just havent had it done yet. trying to get all the small stuff tested first.

 

Sorry, the fix was in a different thread. I found that there was a bad relay on the unit. There are 2 mounted on the ABS pump that I rapped with the plastic handle of a screwdriver. After that the ABS pump worked a few cycles of the key then quit again. IIRC it was the silver one that proved defective in my case.

The relays are available if you look, found mine on EBay. Thing is, look for them by the Bosch numbers, not by the car. The same relays were used in a lot of different cars: VW, MB, Porsche, Volvo to name a few.

Here's what I found in my research:
ABS Relays

Update: Went back and started looking up some of the models
Module Relay 0332002171: BMW E30 ABS Anti Lock Brake Pump Relay 318is 318ic 325i 325is 325ic 325ix
Mercedes W126 W123 W107 W124 W201 relay 0332002171
0 332 002 171 | PORSCHE / AUDI / VW OEM ABS PUMP RELAY
Solenoid Relay 0332205003; BMW E30 Mercedes Corvette ABS Pump Breaking System Relay Bosch 0332205003
NEW Bosch Relay (ABS) 0332205003 BMW 34511154919
ABS SYSTEM RELAIS VOLVO 740 - 760 - 780 - 940 - 960 / BOSCH 0332205003

Possible alternative for 0332512006: 0332512007. That one has a skirt that would have to be trimmed, but first look appears it may be the same relay in a different housing.

I was just going against the Bosch numbers on them I wrote down from mine:
Module Relay: 0332512006 - Looks like there's another possible but would have to do a little trimming on it.
Pump Motor Relay: 0332002171
Solenoid Relay: 0332205003

 

Thx.
I got the front sensors cleaned today. they looked fairly new, just had some oil on them, the rears were caked with black material. Took the car for a drive, still have the light.
On to further testing, going to see if I can meter test them to see if they check out that way.
Will give on the relays a try.
I know the module one that clips inside the compartment is good, cause I can hear it click when I hit the key.
It sucks that Bosch and Chevy think these cars arent worth saving and ditched keeping parts around.