4WABS Indicator Problem

13948 Views 12 Replies 2 Participants Last post by miesk5, Apr 17, 2011

strange

Discussion Starter · Apr 13, 2011

Well here is everything I have tested, here comes info overload.

Key On the abs light comes on.
Abs is not working
When you try to go to test mode the light will not turn off, so you cant count any blinks if it never goes dark.

Test Light will not light up at the test plug under hood.(There is continuity between pins C and E) So there is no way a light is gonna light up with out any current

(I dont get how under hood test is suppose to make light come on with pin C and E, Pin E is a ground and pin C is also a ground when its triggered by the abs computer)

With ABS computer unplugged, light still lights up.

With all ABS relays and diode pulled, light still lights up

If you pull (inside fuse 17) to the cluster, light will not come on

Pulled abs computer plug and there is GROUND at the pin for the light.

Pulled main plug from firewall. Engine side of plug to abs computer there is continuity in the indicator light wire, and no short to ground, so that checks out.

But on firewall side of plug, the pin for the indicator light has continuity to ground (with and without fuse 17 installed)

Is there a common place on the inside wiring harness to cluster that might short to ground at some point?

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miesk5

· #2 · Apr 13, 2011

Yo

Here comes my shot @ info overload; but it is 1/10th of What Ford's testing would give you

I can't concentrate on some of the info you provided because we're ready to roll now; so let's look at the basice and what Ford has provided in general

I know we can look @ Chilton on line via local library for Ford's pin-point testing...
or if someone has the 95 EVTM/PCED/Serv Manual that would be good!

Key On the abs light comes on.
Abs is not working
that's according to specs

When you try to go to test mode the light will not turn off, so you cant count any blinks if it never goes dark.
that's not good at all; my 96 had same issue and it was a bad Module (also called 4wabs computer) .. under washer/coolant rec tank...

Test Light will not light up at the test plug under hood.(There is continuity between pins C and E) So there is no way a light is gonna light up with out any current

If you pull (inside fuse 17) to the cluster, light will not come on
that is the fude for that lamp

Is there a common place on the inside wiring harness to cluster that might short to ground at some point?

Some possible issues:

Fuse 13 Blown, Stop & Hazard Lamps, Stop Sensor for Anti-Lock Brakes (ABS), Speed Control & PCM Short Circuits, Common Locations TSB 95-02-11 for 94-95 Bronco & F Series; wire harness may be pinched/shorted behind the dash where the 14401 wire assy may come in contact w/a sharp edge on dash panel wall - had same short here too; caused E4OD's TCIL (OD switch-LED) to blink like friggin pia; wires pinched @ brake/tail lights - my 96's stop/turn/tail lights wires were almost cut in half on passenger side against 1/4 panel (inner); wires pinched @ high mount brake light & @ driver's left hand seat belt anchor bolt @ base of B Pillar. See the location diagram
Source: by Ford via Chilton

----------

In Power Distribution Box
[URL="http://broncozone.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=10312"]Diagram in a 95
Source: by Seabronc (Rosie, Fred W) at Ford Bronco Zone Forums ==============

Fuse E Blown, Short Circuits, Common Locations TSB 95-02-11 on 94-95 Bronco & Trucks; Miesk5 Note; also see TSB 95-5-21 for 92-95 Bronco & F Series
Source: by Ford via Chilton

--------------------

TSB 95-5-21 Fuse "E" Inoperative - ABS Light On - Back-Up Lamps Inoperative - DRLs Inoperative - MIL On - Speedometer Inoperative
Publication Date: MARCH 13, 1995

LIGHT TRUCK: 1992-1995 BRONCO, F-150-350 SERIES

ISSUE: On some vehicles the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions:
ABS light on
Speedometer inoperative
Back-up lamps inoperative
Daytime running lamps inoperative
Trailer battery charge relay inoperative
MIL on, displaying Codes: 172, 173 or 41 for HO2S failure
Inadvertent PCM Self-Test

ACTION: Replace the damaged wire harness and HO2S sensor. Refer to the following procedure for service details.

SERVICE PROCEDURE:
1. Disconnect negative battery cable.
2. Disconnect the solenoid terminal and positive battery cable from the starter.
3. Pull the cable downward to inspect the 12A690 harness for chafing, pinholes, etc. If necessary, remove the convolute and tape from the 12A690 harness located next to the lower RH side engine mount.
4. If the 12A690 harness is damaged, replace the 14B060 assembly (F5TZ-14300-EA) and the HO2S sensor (F4UZ-9F472-A).
5. Inspect Fuse "E" and replace if necessary (D9ZZ-14526-D).
6. Clear all codes stored in memory.
7. Retest and verify the concern has been resolved.

PART NUMBER - PART NAME
D9ZZ-14526-D Fuse - 15 Amp
F5TZ-14300-EA Harness Assembly
F4UZ-9F472-A HO2S Sensor

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION - DESCRIPTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TIME
950521A - - - - - Replace Harness Assembly, HO2S Sensor And Fuse "E" (If Overloaded) - 0.7 Hr.

by Ford via Steve83

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miesk5

· #3 · Apr 13, 2011

� Chafed wire insulation or pinched wire due to improper routing causing intermittent short.
Action(s) to take:
� INSPECT wiring harness from front brake anti-lock sensors on knuckle to the frame and from the rear axle to the frame for worn or chafed wire insulation.

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strange

Discussion Starter · #4 · Apr 13, 2011

Well I have added a clutch pedal right where one of the problems might be, and i have removed all the EFI and O2 stuff when i ditched the engine, all of which were done at the same time. (ABS worked pre engine swap and immediately didn't after swap)

So a couple very usefull things to check for, thanks ill give those a look

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miesk5

· #5 · Apr 13, 2011 (Edited)

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strange

Discussion Starter · #6 · Apr 13, 2011

I already checked all the fuses but i rechecked fuse E and it was good, removed it, light still on. put it back in and all the trailer relays energized, so that circuit it good. Ill run through some of the links later when I get back home

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strange

Discussion Starter · #7 · Apr 13, 2011

Ok, so did some more tinkering and found out that the 4wabs relay#1 was getting a B+ but was getting no ground signal which comes from the abs computer.

But there was continuity through the wire.

One of the pdfs said to force relay open by jumping terminals, so at the (unpluged) abs comp plug i jumped from ground to relay#1 coil(pin 19). and BAM instant fuse 15 blew.

Figured that was odd it only powers relay coils which take like no power.

So I took that relay over the the battery to see if the coil worked and POOOF cloud of smoke from relay and tried to melt my alligator clip almost instantly.

(My trailer relay box is full of the same off brand relays)
Took another relay from the trailer relay box (same off brand) and i have the same light on problem and cant get codes.

Took out the FORD brand Horn relay, plugged it in and then the self test worked perfectly, whoopie!

If im reading it right i got code 17 and 32
1 flash,pause followed by 7 slightly quicker flashes
longer pause
3 flashes followed by 2 flashes
I took a video of it so i could watch it over and over

Code 32
Right Front Brake Anti-Lock Sensor Diagnosis
Im sure between putting on the lift and doing ball joints and then doing the front u joints that I have messed it up, im surprised there both not bad.

Code 17
Reference Voltage/Intermittent Valve Fault
This one looks like it might be harder to track down.
It says Intermittent connections to battery, main relay or ground. could cause this code, could it be from me unplugging and plugging every in so much the last 2 days trying to test eveything?

Guess I gotta go test and see if ABS works again on the back and front left wheels

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strange

Discussion Starter · #8 · Apr 14, 2011

using this
http://content.chiltonsonline.com/content/images/8492/images/84929150.pdf

I got to step A4 and answered yes i have over 8volts, and the fix was replace ECU. Is it really that simple, that my computers fried?
It still displays codes fine and was working before engine swap.

So on the code 32 I tested the wheel sensor, generated no voltage, but the good side increased voltage as wheel got faster, so thats an easy fix. But this damn code 17 is drivin me crazy

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miesk5

· #9 · Apr 15, 2011

yo

NO

I have to look @ that info again, but I am pretty sure they meant the ABS ECU.

Yep.. it is Not the PCM; it is that 4WABS Module (also called 4WABS computer, etc.)
Here is the diagram again...
http://content.chiltonsonline.com/content/images/8492/images/84929146.pdf
Electronic Control Unit (ECU) is labelled on the 4WABS 40 pic connector on right side.

In the Ford EVTM diagram (by Ford via Steve83) it is labelled as; ANTI-LOCK BRAKE ELECTRONIC CONTROL MODULE

Were you using the "pinout box" (also called the "Breakout Box" or "Anitlock Brake Adapter (ALA)" ) to test?
Break-Out Box Overview; \"...The breakout box put itself between the engine and the computer, and allowed the user to rapciously access the information being exchanged. They are simply a pinout board, mounted in a box, with associated cabling, like this... You can see the way the cabling hooks into the computer and then bridges into the automobile system. A closer look at the pinout board, little holes numbered to correspond to the numbered wires in the connector:The output is readable with a high impedance (this is IMPORTANT- Digital Volts Ohmeter (DVOM) No cheap knockoffs here, they may fry the computer by introducing their own voltage.) Not as fancy as a scanner which decodes the meaning for you, but valuable nonetheless because you can always look up every meaning of the output signal somewhere. Like on the factory manual CD or in the manual itself! FORD decided to make maximum use of the breakout box, and designed add ons to allow you to look at other systems. Here for example, is a harness (still looking new in the wrapper) that hooks into all the Distributorless Ignition System (DIS). It connects to the sensor connectors... allowing you full access to the signals, even while the engine is running: TFI (thick film Ignition) Yes there is a cable for this. Mine cost me $15. Here is the diagram ...There was an adapter for the breakout box that read the brake codes,
... did the procedure for properly bleeding them. It was called the anitlock Brake Adapter (ALA) and looks like this when installed in the unbilical for the breakout box: Between $125 and $200 on E-bay. Worth every penny..." by Glacier991 (Chris) URL CHANGES:

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strange

Discussion Starter · #10 · Apr 15, 2011

Yea I knew they were talking about the ABS ecu, I have a mechanically injected diesel, dont even have an pcm any more.

Not using the breakout box, just measuring out from the pins off of the ecu. As for pin 60, Every bit of data refers back to pin 60 just being a good ground. My multimeter isnt a fluke or anything high end but its a nicer one.

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miesk5

· #11 · Apr 16, 2011

yo,
ok

Sorry, but that A4 mentions using a jumper wire between the BO Box pins before cking voltage; so without that BO Box, I can't determine what pins on the ABS ECU to jump and then measure

So, either buy a box on the net or...have Ford check it and that'll be a prob because of the cost.

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strange

Discussion Starter · #12 · Apr 16, 2011

That jumper it talks about it just sending a ground to the main relay coil to make it turn on.

I need to find somebody else with 4wabs and swap computers to for a couple mins to see if it really is my computer.

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miesk5

· #13 · Apr 17, 2011

yo,

ok, good.
The main reason for 4WABS Module failure are the microprocessors; they tend to self-destruct.

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