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I know, another VSS thread, but I can't make heads or tails of what I found in the search. I found a similar problem, but the poster hadn't tried to alleviate the problem, which I have attempted to, unfortunately.

First off, my Bronco, a 96 XL with a 5.0 and an E4OD. 109000 on her, runs great. Recently, besides the blaring check engine light, the ABS light would come on, then turn off, intermittently. No big deal, I figured, I don't need ABS anyway, right? So, was driving her one day and noticed that it held onto 1st gear for to long, then shifted into second like a built TH 350. Then I noticed the OD light flashing on the shifter. Ruh roh. Drove her home post haste. Cruised the forum and thought maybe it had to do with the VSS, or the little OD button on the shifter. Went to the parts house and got a new VSS, new O2 sensor, cause apparently 96 5.0's have two of em, and new U-joints all around, cause she was still rocking the originals. got all the U-joints changed, new O2 sensor, and new Napa brand VSS in the rear end.

Took her out for a test and bam, no speedo. ABS still on, still shifts like a biotch. More FSB research. Decide on a Ford VSS, thinking my chinese one isn't cutting it. Lay down the cash for the in-stock VSS at my ghetto Ford dealer. Rush home and poke that little feller in the hole, check and blow out the connecter, and plug her back in. Pull her out for a test drive, no speedo, ABS light still on. :(

Not sure where to go from here. I'm not so versed in computer controlled gadgets and cars. I can rebuild carburators, tear down motors and put them back together, I've built a couple of trucks, 4wd and 2wd, no problem. I have no clue what to do with this issue.

Like I said truck still runs awesome, transmission still shifts, hard right now, brakes work, everything works but the speedo.

Any light on the subject is greatly appreciated!! Again, go slow on the computer wizzbangery, cause I don't do well with electronics.

Thanks in advance.
 

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yo,
Have it checked for Codes at a local parts store for free
& Remember to have engine @ Normal Operating Temperature before doing the KEY ON ENGINE RUNNING (KOER) portion
Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.
Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.
Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.

And Post em here according to
KOEO
& KOER


Check Fuses 8 & 18 in Cab fuse block (lower left of dash by driver's left knee)
Diagram in a 96

Source: by Roadkill (The Beast) at SuperMotors.net

If no 12 v on Supply Side of each; look in Power Distribution Box (Located under the hood on the drivers side fenderwell, on driver's side of the air cleaner housing)
and check MAXI FUSES 10 for Fuses 15 and 18 (IP Fuse Panel), Starter Relay
& 20 for Fuses 4, 8 and 16 (IP Fuse Panel). Also See Circuit Breaker 12
Diagram in a 96 by Ford via HardMaple at Ford Bronco Zone Forums

PSOM diagram for 96 Bronco by Ford via Steve83


This problem could be caused by a # of thangs;
cruddy/damaged tone ring in the 8.8.
bad 4WABS Module - It is located below ws wiper fluid/coolant recovery tank. So, the connector can be corroded by leaking fluid
bad PSOM (Speedo)
bad vehicle speed sensor (VSS) (also called ABS,, DSS sensor) sensor on da 8.8 (rear differential)/ or
Connector/corroded wires inside connector;
bad wiring/shorts /connectors from VSS at firewall, at 4WABS Module and /or at PSOM and then onto the PCMthe locations of the connectors along the path from VSS to 4WABS and up to Instr Cluster & PSOM are;

C404 VSS On rear axle sensor (A7) Terminals: 02

C205 LH rear of engine compartment, in safety wall (Fire Wall) Terminals: 24 In-Line

C202F & M LH rear of engine compartment, in safety wall (A8) Terminal: 7 In-Line

C119 LH front corner of engine compartment on 4WABS control module (E10),Terminals: 40

O/LB to:
C202F & M LH rear of engine compartment, in safety wall (A8) Terminal: 7 In-Line

C252 Programmable Speedometer/Odometer Module (PSOM), Behind top LH side of I/P, on PSOM (A7) Terminal: 12 Color: B at Pins 4

LG/Y to Splice S107 Engine control sensor harness, from C119 near T/O to G101 (G101 RH side of Radiator support); to PSOM Pin 5
C202 F and M
and spliced to Ground G100 (BK)
G100 & G104 (tied together in diagram) G100 @ LH front of engine compartment, on upper radiator support

G100 Serves Component:
Fuel Pump Module
Inertia Fuel Shutoff
Misfire Sensor
Misfire Sensor Shield
Output Shaft Speed (OSS) Sensor
Powertrain Control Module (PCM), 5.0L


From PSOM Pin 7 (GY/BK) to Splice S246 Main harness, near T/O to speed control amplifier to
C185 PK/O @ PCM 5.0L Powertrain Control Module (PCM) LH side of safety wall, on powertrain control module (PCM) (C10) Terminal: 104 Color: GY
C185, 5.8L Powertrain Control Module (PCM) LH side of safety wall, on powertrain control module (PCM) (C10) Terminal: 104 Color: GY

C185 @PCM to C202 F and M
Splice 216 to Ground G200, Instrument Cluster ground is inside passenger side kick panel

and on to C185 @ PCM PIN 58 (GY/BK) and from Pin 46 to MLPS (TR) Pin 2
Verify PCM & MLPS wiring & Pin numbers using following WIRING DIAGRAMs by Ford via Steve83
(my eyesight is fuzzy again)
http://www.supermotors.net/registry/media/95931_1


My 96's same symptoms were erratic until the 4WABS Module's microprocessors finally burnt-out. I had one go bad and 2 yard Modules were also bad; so I jumpered the Module out as Steve & Turbo Ghost describes below.

To bypass the 4WABS module @ it's harness's connector & feed the ABS signal directly to the PSOM,
Disconnect module (under coolant recovery /ws washer tank) & in connector, jumper LG/Bk to LG/Y, and R/Pk to O/LB..."
Source: by Steve83 (Steve, That dirty old truck) at http://www.supermotors.net/registry/media/170517_1
Pin numbers are shown in the wiring diagram

or with a pic of the connector and jumpers; Continuity Test Through 4WABS Module Connector in 93-96; "...jumper 14 (CKT 530, LG/Y) to 21 (CKT 519 (LG/BK) & 39 (CKT 491 (O/LB) to 22 (CKT 523, R/PK)...";


Speed Input Signal Test @ PSOM in 93-96 Bronco; "...NOTE: Only wiring harness end of connector is to be probed. * Connect Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent to Pin 4 (speed in ) and Pin 5 (speed in -). * Does the voltage increase smoothly and continuously from 0 to approximately 3.5 volts as vehicle speed increases from 0 to 48 km/h (0 to 30 mph)? OR: If available, a frequency counter may be connected to Pin 4 (Speed in ) and Pin 5 (Speed in -). Does the displayed frequency of the signal increase smoothly and continuously from 0 to approximately 667 Hz at approximately 48 km/h (30 mph)? OR: * If neither a voltmeter nor frequency counter is available, vehicle speed control may be used as a good indicator. If it works normally, then the speedometer module is at least receiving a speed input signal and the wiring and sensor & tone ring can be assumed to be good.
This is tuff to do; suggest using str8 pins to back probe the connector
================
Tone Ring Inspection; "Take off the rear diff cover. Check the Ring Tone gear. It is located on the left hand side of the ring gear. Look to see if any of the teeth have been notched (from debris floating around in the diff.) Usually a spider gear. If the ring tone gear has been notched, it will need to be replaced to fix your speedo reading. Jack it up and rotate the tires to look for the teeth to be notched/broken/bent..."
Source: by Bighibbi at FSB

or pull VSS and use light to inspect tone ring; jack it up, use jackstands, etc.
 

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Discussion Starter #3
Thanks, sorry, I know I've seen you post this before, especially right after I started the thread! I appreciate your help and will report back if/when I figure it out.
 

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Does the mileage change or is it static now? Follow Miesk's instructions.

Sounds like a fried PSOM. There is a way to test it as well. I'm sure it is on Miesk's website or Steve83's supermotors.
 

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Discussion Starter #6
So, I go outside to pull the steed into the stable to start figuring it out. Fire it up, check engine light off. ABS light still on. Back it up, notice the speedo is now working! Score! Drive it around the block and it's working, still ABS light, no CE Light. Pull it into the garage to check fuses. Check all fuses under the dash, pull them all and check for corrosion. Two of the fuses have jumpers on them, to wire the stuff that used to be in the bronco, she was a BLM Bronco when she was new. One of the jumpers was on fuse 8, pulled it off. Fired her up again, NO ABS LIGHT!!! Awesome, Bronco is ready for action yet again. I hop in her and go to take her for a spin, cause it's been so long. Heading down the hill, speedo needle starts to bounce, sometimes a little, sometimes all the way to zero, then back up to correct speed. ABS light comes on again, dammit. Got it up to highway speeds, sometimes the speedo works fine, other times it wavers a bit, or it slams all the way back down to 0, then back up to 55. Transmission doesn't go into Emergency until I stop. Turn it off, then back on, Emergency mode off again. Drive her back home, speedo still bouncing, transmission will shift strangely, as it's confused when the speedo jumps. Still doesn't go into Emergency. CE light comes on, no apparent reason. Drive her all the way home ad park her. Had to go to work, have been working since.

Haven't been able to pull codes yet, but I have hypotheses. First is bad ring gear for the VSS, next is bad wiriing connections, somewhere other than at the VSS plug, cause I've checked it. Next, loose plug into the back of the speedo.

Will check gear in rear end on next day of, then I'll try to track the wire all the way to the speedo to check for shorts. Hopefully I can get it on a Diagnostic machine, parts store round my parts don't have em, and mechanics think they need to charge to hook them up to tell you whats wrong with your truck. Just wanted to update.
 

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yo,
Mine would drive (shift into 2, 3,OD) well until it got to ~50MPH and then it would do da rocket sled slam into concrete wall shifts.
Simple Connector check is @
the 4WABS module (under coolant recovery /ws washer tank)
What I posted previously is a VERY SHORT compilation of Ford's Pin-Point Tests; it ranges from "terminal back-out" in a connector @ at VSS, firewall, at 4WABS Module and /or at PSOM and then onto the PCM/E4OD; to a bad Module or PSOM

Some pull just the VSS to inspect tone ring while Bronco rear is jacked-up or rolled.
 

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Discussion Starter #8
I'm going to pull the VSS to inspect the ring, sounds a bit tricky though. I'm a one man show, but I'll figure something out. Sometimes it acts like its a bad connection, other times it acts like its missing teeth on the ring. Any one know about the VSS relocate idea? I've thought about just doing that if the gear in the 3rd member is bad. I will trace some wires also, as always, will report back with what I find. Thanks for the responses!!
 

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did you see my post? very similar symptoms...I didn't have the ring with the teeth AT ALL! It did take my mechanic to pull codes though that lead him to pull the cover on the rear diff...

good luck and let us know the outcome
 

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Discussion Starter #10
Just read your thread, sounds real similar to my problemo. Did your mechanic pull the gears out of the rear end and put in the tone ring? I take it you had to buy the 96 gear cluster, sounds expensive. I haven't been able to check the rear end yet, but I think it's going to be my problem. How difficult is pulling the planetary and spider gears out of the 8.8"? I've never pulled a third member apart before, just swapped em out when they went tits up. Sorry it cost you so much cash to get the steed back on the road, sounds like yourn is real similar to mine. On a way cool side note: Found a set of stock aluminum wheels for the Brick for $75! Pretty decent shape, may end up getting powder coated, they have some salt etching on them I'm not thrilled about, but they're better than my steel XL rattle can wheels.
 

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Discussion Starter #11
It's looking like VSS relocate is going to be the most viable option for the Brick. Still have to crack open the rear end to confirm the problem is the exciter ring. They don't like to give me any time off here lately, so it's been sitting in the car hole not getting muddy. :(
 

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yo,
BRONCO808 had an unusual situation, but it happens when previous owners or shops don't unederstand how Ford designed the system for the PSOM, 4WABS & tranny controls thru PCM in 92-96 Broncos.

Read my reply again for the simple checks; If neither a voltmeter nor frequency counter is available, vehicle speed control (Cruise Control, assuming you have it and recall work was done) may be used as a good indicator. If it works normally, then the speedometer module is at least receiving a speed input signal and the wiring and sensor & tone ring can be assumed to be good.

If VSS (also called called RABS) turns out bad, buy only a Ford Motorcraft sensor via AMAZON or thru Ford, etc.
 

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Discussion Starter #13
I did buy a direct from Ford VSS, which solved the no signal problem single handedly. i had pretty much resigned to the fact that I was going to need to do the VSS relocate mod. Just to ensure that the Excited ring was the problem, I pulled the rear diff cover. The gear oil smelled like it had never been replaced, but the bathroom caulking used for RTF told me otherwise. how it wasn't leaking I'll never know. Checked the Tone ring, beautiful, just as Henry intended. Couldn't check the gap, cause of the odd angle and my giant hands won't fit! Eyeballed it and it looked pretty good. Was trying to get a better angle when I looked at the wiring loom for the VSS, right in front of my face, and notice a gap in the protective plastic. In said gap, there was two wires, one red, one green, both of which had a small section of insulation stripped off, exposing bare wire!! The wire had been exposed for a while, cause the copper was discolored. Cut out the bad wire sections, re-connected. New gasket and gear oil put back in the diff. Fired her up, ABS light OFF!!! Took a small test lap, no bouncing of speedo, no emergency mode transmission shifting. Haven't fully confirmed that problem was solved by full road test, so I don't want to say, "Problem Solved" just yet. I'm keeping my eyes crossed though. Lesson learned: Check all of your damn wiring three times!! Twice obviously wasn't enough.
 

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Took her out for a little road test and all is well! Had to replace the full positive battery cable assembly due to excessive corrosion inside the wires. New solenoid on the firewall too, just in case. Running like a champ now. Thanks to everyone who helped get me thinking on this project, greatly appreciated.
 

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Hi my name is tim I had just bout a 93 for bronco and it has the same problem any help I can get would be help full thank u have a good day
 

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Bought a 94 Bronco with hard as bleep shifting, ABS light on, and speedo not moving. It came with a second speedo that also didn't move. I'm looking forward to troubleshooting VSS now! I'm just wondering if the voltage is AC or DC. I reckon that I'll figure that out right quick.
 

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Bought a 94 Bronco with hard as bleep shifting, ABS light on, and speedo not moving. It came with a second speedo that also didn't move. I'm looking forward to troubleshooting VSS now! I'm just wondering if the voltage is AC or DC. I reckon that I'll figure that out right quick.
yo phried;
AC voltage; although Ford does not state it is AC (or DC) in pin point tests; as shown in 1996 F-150, F-250, F-350, Bronco, F-Super Duty Motorhome Chassis Workshop Manual
excerpt;
"G8 CHECK SPEED INPUT SIGNAL
NOTE: Only wiring harness end of connector is to be probed. Vehicle speed control may be used as a good indicator. If it works normally, then the speedometer module is at least receiving a speed input signal and the wiring and sensor can be assumed to be good.
Connect Rotunda 88 Digital Multimeter 105-00053 or equivalent to Pin 4 (speed in +) and Pin 5 (speed in -).
Does the voltage increase smoothly and continuously from 0 to approximately 3.5 volts as vehicle speed increases from 0 to 48 km/h (0 to 30 mph)?
..."

Programmable Speedometer/Odometer Module


BRONCO Pin Number Circuit Circuit Function
1 54 (LG/Y) Battery Input
2 676 (PK/O) Ground
3 296 (W/P) Power (Hot in RUN)
4 491 (O/LB) 4WABS Signal Input
5 530 (LG/Y) 4WABS Signal Return

6 — Not Used
7 679 (GY/BK) Speed Output to Instrument Cluster, Speed Control Amplifier to Powertrain Control Module, and Compass
8 — Not Used
9 567 (LB/Y) PSOM Programming Connector
10 — Not Used
11 — Not Used
12 — Not Used
 

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The VSS in my truck was reading 1800 Ohms (not within tolerance) and only giving 0.1-0.8 VAC while running the truck with the rear diff up on jackstands. I got a bag of parts with an extra VSS in it that was reading as 1000 Ohms (within tolerance) so I stuck it in and saw ~1VAC-3.8VAC at the test point between the ABS module connector's pins 21 & 22. The resistance was only marginally higher when tested up at the connector and that is a good thing! I tried replacing the very worn O-ring on the VSS and found that the voltage range wasn't getting back up to the previous values (that sucker's tolerance is SENSITIVE!). But just for shoots'n'giggles I reconnected the ABS module and hooked up the speedo and got nothing. My next step is jumpering the pins on the ABS module. To see if I can at least rule out bad wires. Big props for the photo of the connector posted above.

I'm trying to find the appropriate replacement sensor on Amazon but not having any luck. Does someone have the correct Ford/Motorcraft part number?
 

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I'm trying to find the appropriate replacement sensor on Amazon but not having any luck. Does someone have the correct Ford/Motorcraft part number?
yo P,
See Ford pn @; http://www.fordparts.com/
It's Listed under1994 Ford Bronco > Brake > ABS Components

2L373 (BRAB-130) ABS Sensor
Located in rear axle housing, used as ABS sensor
FORD shows it is superceded;
Part #: BRAB-130
Manufacturer: Motorcraft
Description: ABS Sensor
Motorcraft Supersession info: Buyer's guide
Part #: 2L373
Manufacturer: Ford
Description: ABS Sensor

Rock Auto shows;
FORD Part # FORF000820 {#DY1123, F85Z2L373AC, F85Z9E731AB} Differential Mounted ABS Sensor
4WD; Rear Differential Mounted ABS Sensor for 7.5", 8.8", 10.25" Ford.
$21.79
http://www.rockauto.com/catalog/raframecatalog.php

for other PN's incl Emission parts and PCM, etc.;
Vehicle Emission Control Information (VECI) Decal; Contains Vacuum Diagram & Calibration Parts List for 88 & UP. On-Line for Free at Ford. Click "Quick Guides" in left panel; Scroll to & CLICK VECI Labels "Provides Vehicle Emission Control Information (VECI) and a related calibration parts list." Enter applicable info (need to know your Calibration number (also called catch code) from your B-pillar sticker). Vacuum Diagram is the same as the one on the core support or hood or air filter cover. Suggest Right Clicking this Hot Link & Open in New Window
Source: by Ford http://www.motorcraftservice.com
 

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Word. Up. Thanks, man. It was a real bugger to find that part. I'm going to go ahead and pay up for the $36 part and while I'm waiting for it to arrive I'll try the ABS conenctor jumpering to see if the ABS module is shot as well.
 
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