I have an 87 Bronco II.
A garage replaced the rear wheel cylinders and then bled brakes.
Now getting Rear ABS light.
My Haynes manual doesn't tell you ANYTHING about the rear ABS other than where the three components are.
I've replaced the rear sensor in the axle.
I bled the rear proportioning valve only (not wheel cylinders) as its valve showed no signs of being bled after they replaced the rear wheel cylinders.
When I start, the ABS light comes on and then goes out (as normal) IF I keep my foot on the brake... As soon as I lift my foot off the light comes on.
Here are the questions:
1. Where do I connect to read the codes for the ABS controller? There is no connector at the module in the side panel behind the driver's seat.

2. Can you give me a list of codes? (or if there are too many) where can I get the list? Haynes is useless (It says "take it to the dealer!")

3. What is the correct bleed procedure for this rear system? I've seen on a few of the forums about special toosl... If a special tool is required where do you attach it and what is it supposed to do?

I appreciate the help!

Dave

 

I don't have all of the answers for you but would start off by suggesting that you delete the codes (if you haven't already). You can do this by unhooking the negative battery cable for at least two minutes. I am not sure where the connector is but I doubt it is behind the drivers seat. They are normally under the dash on the driver's side. If you search this site for a list of codes I am sure you can find them, you can also find detailed instructions on how to pull them. I know I have read them somewhere here before and I believe you might be able to go to fordfuelinjection.com and get more information. I know its not too specific but I hope it gets you started.

 

1081,
Thanks I hadn't tried clearing the codes at this point. Good suggestion

Dave

 

Clearing the codes sounds like a good idea to me also. If you still get the ABS light heres what the shop manual sez for pulling the codes.
With engine running & only the yellow ABS light on (red brake warning light is off) ground the pigtail at the computer module for one second, then read the flashes on the ABS light. Remove the trim panel behind the drivers door post to get to the computer module. A long flash then 2 quick flashes equals code 3 etc.
What does the shop that did the brakes say about this?

 

87 XLT

The shop that performed the work is in the town where my son goes to college (read dad's broke)... As they performed some work and most of it was shoddy I swapped cars to repair this brake problem (and some other problems which I've cured).

I only have the RABS light (no brake light)...
I think you're on to something... Your insight as to grounding it at the module is the first I've heard to do it there. Everybody else has said use a single wire connector under the dash with a BL/OR wire...which I cannot find either... Do you know which wire of the 15 or so to "ground?" There are two power wires that I have from the manual so I'm down to 13 left... I don't see a BL/OR...
Which to choose???? Which to choose???? Zap!...Argh! What did I fry now?

Thanks,
Dave

 

More news on this deal... Thanks to XLT...I found an BK/OR (not BL/OR) single connector at the module as a separate connector...

With the ignition on RABS on too...(and/or engine running) when I ground this connector for one second the light does NOT flash or change state...I tried holding it for longer with no change and no flash codes...

If I hold the brake pedal so the RABS light is out when I switch to run then ground the connector the light comes on steady. As soon as I "unground" the connector the light immediately goes out and I get no flash codes....

Is this real bad news that the RABS module is shot?????

Thanks all for your help so far!

Dave

 

Somehow, i'm not finding the color code for that wire, but it should be a single wire with pig tail which is hanging loose from the computer module. BTW, i've got the list of codes & pin point tests. Good luck with it.

 

From the shop manual "Caution when the yellow anti lock warning lamp glows, this indicates that the anti lock system requires service. Do not shut the vehicle off. In certain conditions, shutting the vehicle off loses the ability to read the flashout code without reproducing the service condition code. To obtain the flashout code: if the vehicle has been shutoff & the code lost the vehicle must be started up and/or driven to reproduce the condition." So it might be a timing issue that is causing the no code.

 

Dave, depending on what the red brake light & ABS light do when you turn the key to run there are some different tests that you need to do.
So turn the key to run (test connector not grounded) & tell me what the warning lamps do.

 

Diag connector NOT grounded...
Key to run
Brake light out (never comes on at all)
RABS light on for about 5 seconds
then off for about 2 seconds then back on steady (if not applying brakes).

If applying brakes:
Key to run
Brake light out (never comes on at all)
RABS light on for about 5 seconds
then off and steadily off until the brake is released...
Then the RABS light comes back on steady.

The rear proportioning valve makes a "click" sound when the light goes off after the five seconds. Then the RABS light comes back on...

The brake light comes on when I apply the parking brake...So it seems to be working...

Thanks for the help...

Dave

 

I tried various combinations to get the code...
I started the engine (not applying the brakes)
I started the engine while I applied the brakes
(I must have looked like a contortionist...left foot on the brake, drivers seat folded on steering wheel, left hand on key at column to start, right foot on ground, right hand on RABS controller connector and head inside BII. phew!)

I haven't tried driving it to "log codes" again... I'll try that tonight...

 

Rereading the timing statement I have one more question...
Shouldn't I get the "All normal" DTC of 16 when I ground the connector?
I'm not getting ANY flashing whatsoever...

Thanks,
Dave

 

Not finding a match for RABS on then off then on steady. One thing that IS mentioned is that the red brake indicator should be on when emergency brake is applied. Do you have that? BTW, thanks for this reminder of why I never have & never will purchase a vehicle with ABS.

 

OOPS, just reread your last post & I see that your E-brake does turn on the red brake light. Closest thing I can find to your RABS light on/off/on is RABS light comes on & stays on. With ABS light on apply E-brake & red light should stay on. Release E-brake & ground the test connector if NO CODES are flashed "disconnect module" & check for 11 to 13 volts between pin one & ground with KOEO. No voltage, check the 20 amp RABS fuse. If voltage is good check connection of the master cylinder fluid level switch. Then remove the connector from the master cylinder switch & connect a jumper between the two purple & white wires of the connector. KOEO & both brake lights should be on.
I have a feeling that with the short wheelbase of the B-2 the RABS is a necessary evil to keep from swapping ends during hard braking, but it can obviously be a PITA to repair. With all the cars/trucks/motorcycles that i've owned i've never had a problem with simply hitting the non ABS brakes just short of lockup & steering around any obstacle. Enough with my little anti ABS rant, hope this helps.

 

I'll give these a whirl tonight or tomorrow morning and post another thread...

The ABS was intended for the less than cautious driver who really shouldn't be driving to begin with at speeds over 20mph... So when they panic and slam on and "hold" the brakes the car still has some steering...

I can also think of several times where the ABS has prevented me from stopping when I wanted to just LOCK-EM at slower speeds...


Thanks,
Dave