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1st RFM/FFR Legacy Winner
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Discussion Starter #1
Granted I've only tested the newly installed 1995 ABS on the FFR with hard stops from about 30 mph, I can't see that it's preventing wheel lock up. I can still slide both front wheels. The sytem is passing power up self-tests and generates no error codes while driving. I checked the wiring again and it's ok, with special attention given to the brake light stop switch input to the ABS module.

Could it be the ABS does not operate when stopping from speeds lower than some threshold? Maybe I need to try a panic stop from a higher speed?

Does anyone know for sure from what minumum speed the 94-96 ABS will operate on your FFR or your Mustang DD.

Thanks,
Greg
 

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Should be quite a bit lower than 30 mph, i would guess less than 5 mph based on production cars i have driven.
 

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The Greek
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Greg,
ABS should work ANY time the wheels lock up. Speed does not matter.
One possible issue that you might have is that the ABS pump itself was at one point drained from brake fluid. This causes the solenoids in the pump to close and stay closed, thus rendering the ABS useless. But, you still have regular brakes.
So your brakes might be functioning as if not having ABS.
In order to get the ABS solenoids to open again, the ABS diagnostic port needs to be hooked to an ABS tester/reseter which the Ford dealer has.
I have the EXACT same issue as you, and I had drained the pump dry. I thought it would be good so no old/dirty fluid was left in the system. All wiring is correct and my
ABS light functions correctly i.e. ignition on, light goes on and then turns off after a while.
HTH
 

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1st RFM/FFR Legacy Winner
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Discussion Starter #4 (Edited)
Just to be clear, you have the 3-channel 1994-1995 including some 1996 models. I read these years don't have a means to reset the controller. That started in 1996 and later. Do you by chance have a photo of yours?

Did you have yours reset and now it's working?

Thanks,
Greg
 

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The Greek
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Yes mine are out of a '94 so they are 3 channel. From what I have read, these also can and need to be reset. I might be wrong, but on line searches lead me to believe the above. It also makes sense since all electronics work, but the actual ABS function does not.
No, I have not reset it as of yet. I will though....sometime soonish.

Here is a photo

 

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I have the same one on my 95 mustang and you can feel it work if get on some wet surface well below 30 mph..
 

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1st RFM/FFR Legacy Winner
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Discussion Starter #7
Yes mine are out of a '94 so they are 3 channel. From what I have read, these also can and need to be reset. I might be wrong, but on line searches lead me to believe the above. It also makes sense since all electronics work, but the actual ABS function does not.
No, I have not reset it as of yet. I will though....sometime soonish.

Here is a photo

That's the same one I have. I found this info on bleeding after controller replacement:

For the 2002 and earlier Mustangs without Traction Control, the ABS valve block or pump and motor assembly does not require any special bleeding procedure. For the 1998 and earlier Mustang ABS systems, there are NO Special Procedures or Considerations in bleeding the system.

Directly from the 1998 Ford Service CD section for the Mustang.
Anti-Lock Brake System Bleeding
Service or replacement to the ABS valve block or pump and motor assembly does not require any special bleeding procedure.
Follow manual or pressure bleeding procedures.

For 1999+ Mustangs, with Traction Control, you SHOULD use a bidirectional controller when the ABS controller, MC, or any line between the two the Master Cylinder is replaced or opened.

Four Wheel Anti-Lock Brake System (4WABS) Hydraulic Control Unit (HCU)

NOTE: The following procedure only needs to be performed if the 4-wheel anti-lock brake (4WABS) hydraulic control unit (HCU) has been installed new or if the HCU lines have been opened.

Special Tools:
Worldwide Diagnostic System (WDS)
418-F224,

New Generation STAR (NGS) Tester
418-F052, or equivalent scan tool
NGS Flash Cable
418-F120 (007-00531) or Equivalent

Connect the scan tool DCL cable adapter into the vehicle data link connector (DLC) under the dash, and follow the scan tool instructions.
Repeat the system bleed procedure as outlined in Steps 1 through 5.

http://www.veryuseful.com/mustang/tech/brakes/bleeding.html

I need to speak to a Mustang mechanic to be sure.

Thanks,
Greg
 

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The Greek
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Greg,
thank you for that info!!! Now I am confused!!!
In my car, I can not really get the tires to brake lose upon stopping due to the size, but I will get some chirping (from the tires when stopping hard). Not sure if that gives the ABS enough time to do what they are supposed to. I am pretty sure the wiring is correct.
PLEASE let me/us know what you find out from a Mustang/Ford mechanic as I have no one to ask but the forum members.

Hope we get this figured out!!!
 

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1st RFM/FFR Legacy Winner
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Discussion Starter #9
On the 94-95 ABS controller there are only two wires in the diag connector and only one of those wires is considered diagnostic. When that wire gets grounded at power-up it places the unit into a mode that indicates the codes with a series of ABS lamp blinks. The other wire is an extension of the ABS lamp to under the hood that will flash the codes locally so you don't have to run around to the dash to view them.

I see no way our ABS units could accept a code reader or programmer.

See wiring here : http://www.worldisround.com/articles/123897/photo549.html

Greg
 

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1st RFM/FFR Legacy Winner
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Discussion Starter #10
Just confirmed the 94/95 controller is a Bosch 2U. The 94/95 Bosch ABS units in the Stangs have a "uni-directional" diag connector. You can only "read" the ABS codes. You can not flash (on any Bosch "2U/3U" series ABS unit).

I also read if the controller doesn't sense ANY pulses from ANY wheel sensors while driving, it can't tell the car is moving and won't operate ABS when pin 9 of the controller connector goes to 12V i.e., BOO (brake on/off) swich is pressed on the brake pedal. It also won't produce any error codes.

I verified all sensors are producing an AC voltage meaured at the point where the plug fits the controller. I question the phasing of the sensors now since I'm running out of ideas. I will swap the phase (reverse the +/- sensor wiring at the terminal strip (easy to do) and see if that changes anything (when the rains stop)

Greg
 
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