Speedo Issues

[miesk5]

Yo tjg8675,

YW!

Nice looking stance on your Bronco!

I have to continue on 95 to 96 Bronco changes soon. 96 is same as most earlier years especially 92-96, except for:

OBD II in 96;

4WABS (93-96);

RABS (87-92);

Air Bag (94-96);

3 ***** Automatic Locking Hubs (Built from May 95 through 96); Spark Plug Wire Routing & Firing Order (The firing order for 1987-1993 5.0Ls is 1-5-4-2-6-3-7-8. The firing order for 1994- 96 5.0Ls & all 5.8Ls is 1-3-7-2-6-5-4-8.);

R134a in 94-96;

2-piece Spindle Rolling Diaphragm Seal (RDS) used on 5/95 to 96 Broncos & F Series 1/2-ton 4WD;

Mass Air Flow in 95 5.8 California models and in all 96s, other years used Manifold Absolute Pressure Sensor (MAP).

96 5.8 do not have the Air Injection (AIR), Secondary Air Injection; Pump (Smog Pump), Thermactor Air Bypass (TAB) & Thermactor Air Diverter (TAD) Solenoids; Diverter, Check & Bypass Valves, Cross-Over Tube, etc. But 96 5.0 does have the system.

The 96, Vapor Management Valve (VMV) replaces the canister purge valve (CanP valve) used in EEC IV.

Still researching other differences.

Here is 96 Bronco-F-Series Workshop Manual (PARTIAL) by FORD via

http://www.diesel-dave.com/vehic/manual/stj/stjleft.htm

 

[tjg8675]

Hello miesk5, quick questions regarding this photo...the black wires stay in this location when you bolt the 4wabs controller back to it? do the wires cause a gap/bad seal? do the pins fit the holes ok with the wires in them?

If this doesn't fix my needle waiver and I have verified VSS's are good, should point to a bad ABS tone ring?

 

[tjg8675]

are PSOM from F-250, E-150, mustangs, ???, etc. interchangeable with the bronco?

 

[tjg8675]

can you diagnose bad tone ring without taking off diff cover?

 

[miesk5]

Yo,

***If PSOM Needle jumps or wavers at a constant speed it could be caused by tone ring's aka SPEED SENSOR RING's:

Damaged, missing or bent teeth

Metal chips on VSS

Open or shorted VSS

Improper gap between sensor and speed sensor ring. by Ford ***

----

The connector does not get hooked back to the 4WABS module.

I hung the harness and the connector next to radiator and wrapped it in a zip lock baggie with open end facing down.

----

From what I have HEARD, 95 F-250 & E-150 PSOMS are same as Bronco PSOM. CLUSTERS are different though.

---

Mustangs probably not the same; and I never heard or read about a swap to a Bronco. But, this statement is interesting, "The speedometers and odometers for all years and models from 94-98 are interchangeable because they use the same 8000 pulse-per-mile VSS signal and they have the same connector to the cluster circuit. The speedometers in V6 cars go from 0-120MPH, GTs from 0-150 and Cobras from 0-160MPH. The odometers are interchangeable from 94-98 clusters."

@

http://web.archive.org/web/20100323021905/http://accutach.com/FordClusterInformation.aspx

But, note that our 92 through 96 Broncos use same 8,000 PULSE/MILE VSS signal TO PCM; the rear axle mounted VSS provides a signal via the 4WABS module to PSOM that converts this signal to 8,000 pulses per mile. That signal is sent out to the PCM and then to:

E4OD,

speed control amplifier;

and overhead consoles compass/outside temperature display module, if equipped.

If the thermometer sensor (mounted behind the front bumper/grille) data indicates a higher temperature, the module uses a high-speed counter to monitor vehicle speed to determine whether engine heat is causing erroneous readings. The counter is incremented when the speed is greater than 53 km/h (33 mph) and decremented when the speed is between 16 and 53 km/h (10-33 mph). If the speed is less than 16 km/h (10 mph), the counter is reset, and the displayed temperature is not updated from its last reading. If the counter is greater than two minutes, the currently sensed temperature is displayed. If the high-speed counter has counted less than two minutes, the temperature can increase only one degree per minute.

http://www.diesel-dave.com/vehic/manual/stj/images/k17799c.gif

So I learned something new about the overhead console's use of the VSS signal via the PSOM signal!!! I did edit my previous comment on the console on page 1.

---

The vehicle speed control may be used as a good indicator. If it works normally above 56 km/h (35 mph), this means that the speedometer module is at least receiving a speed input signal and the wiring and sensor can be assumed to be good. by Ford

...

 

[tjg8675]

Ok thank you miesk5,

lots of good info as usual...

Does model year have to match PSOM? ebay only sells 92-96, from first glance (I haven't tried to ask specific model yr of part)

I wondered about the mustangs only because they shared the 5.0l motor (87-93) I think they have different instrument panel altogether tho

I was able to get another 95 bronco 4wabs controller from the junk yard over the weekend ($20 bucks why not!) and I plugged it in and still have pulsing pedal issue when over 10 mph when applying the brakes (no abs light).

So it got me wondering if something else was up.

try to follow me here if you can...

I replaced the 2 front VSS when I had my front end worked on last dec. (needle still waivered, pedal still pulsed)

I determined that the rear VSS must still be good after trying out a new one from o'reillys and symptoms persisted (needle still waivered, pedal still pulsed)

I guess the only thing I haven't tried is replacing the PSOM altogether or jumping the VSS to PSOM to see if that improves needle waiver any.

Can I test rear VSS? (I know multimeter resistance method, better way?)

Can I test tone ring without opening up rear diff cover? (by using multi-meter on VSS and jacking up rear end and running up the MPH to 30 to test for smooth current rise? -I thought I read this somewhere)

sort-of narrowed down to -

Bad ABS tone ring

Bad Rear VSS (Rear VSS resistance test passed - circuit opens briefly then closes)

Bad PSOM (how do I find a PSOM3 LEVEL CLUSTER? what model yr did this start?)

maybe 2 bad 4wabs controllers? miesk5, I know you have said you tried a few and they were all bad /emoticons/[email protected] 2x" width="20" height="20" />

current symptoms -

no ABS light btw (does work - turns on when I remove ABS motor fuse)

needle waiver (over 25-30 mph, small waiver low speed - large waiver highway speed)

pulsing brake pedal (over 10 mph)

sluggish shifts from 2 to 3 and from 3 to 4 (I think due to bad speed reading over 25-30 mph)

Cruise control does not work, won't stay engaged

Kinda lost... need pointed in the right direction, I think I'm probably going about this wrong way and need turned around.

Just like my dog, I will run in circles until someone grabs my leash and leads me somewhere I guess.

sorry for so many questions

any suggestions greatly appreciated, thanks for all help so far

 

[miesk5]

Yo,

Try jumping the connector.

..

Any 92 through 96 Bronco or F Series PSOM WILL swap. As you know the clusters are not interchangeable between Broncos and F Series because of our tailgate window switch, etc.

I have seen Broncos and other vehicles on a Lift, secured with chains and ran up to speed to test or find transmission leaks, but not too much on the road. Except once and that was by my dad who was very old school diy, make that old farm school diy. I can not recommend doing this yourself, sorry. BUT Some inspection of the tone ring can be done by removing the vss and doing this without removing the diff cover;

Tone Ring Inspection in an 8.8; "...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..."

...

Just found this...Some additional reasons for speedo needle waiver on PSOM clusters;

Exciter ring chipped or damaged 60% of the time

20% of the time is the VSS

10% of the time the air gap is too wide and should be 15-20 thousandths

Wiring issues (pinched, open, intermittent, pins pushed out of connector making poor contact, etc.)

Drive line angle bad could cause waiver around 5% of the time

& You can reference TSB 96-21-11 but PSOM3 level clusters for only a speedometer needle waiver concern are no longer available. All other repair inquiries are welcome

by

http://www.fordclusters.com/ford_psom_instrument_cluster_repair

.

Here is TSB 96-21-11, also addresses tone ring damage, etc., vss to tone ring air gap and using PSOM3 LEVEL CLUSTER...;

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.revbase.com/BBBMotor/TSb/DownloadPdf%3Fid%3D42029&ved=0ahUKEwjqpLeY7dLPAhWGcT4KHWMFCo4QFggeMAA&usg=AFQjCNFrfonfJKR9nH6zunfzHXr0aW6UKQ&sig2=mMKn2v6u-PUXW7HyKlF-dg

...

You can swap just the PSOM OR individual gauges into your existing cluster.

Similarities, Mounting, & Removal info & pics; "...The PSOM, lens, blackout ring, terminal clips, shifter plates, bulbs & holders are interchangeable between cases.

87-96 gauges are only held in by their terminal clips;

92-96 PSOMs are held captive by the surrounding gauge faces. The fuel, oil, & temperature gauge bodies are identical & interchangeable by prying the needle off & removing the 2 screws holding the body to the face plate. To reinstall the needle, the gauge must be powered & have a known signal applied (usually the minimum) before stabbing the needle so it points to the proper reading. The screws are 5.5mm (7/32") hex with T15.

..

The pulsing brake pedal is perplexing in that the Amber ABS light is not On while driving, but is on when first starting.

You can try a self test for codes, but doubt that you will see a code.

So am thinking it is a mechanical issue such as a warped rotor, etc. See,

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.aa1car.com/library/brake_pedal_pulsates.htm&ved=0ahUKEwiU1u337dLPAhVEbD4KHWnBAPYQFggbMAA&usg=AFQjCNFgOJw6yxZ-qLqIOFhTOd31bd7grw&sig2=dCYw_oQl4Kioi6dqtOsgKA

...

Cruise control does not work indicates that if the recall was done, anything from VSS through module and psom itself are the usual suspects.

...

No problem asking, ever.

BTW, all that I have suggested are things I wish I could do now. I know how it is to have a daily driver and have to do these types of tests with no one around to help or even hold a flashlight.

 

[tjg8675]

Hi miesk5,

thank you for all your support, not only am I a one man show but I have a torn muscle in my dominant shoulder which cuts my productivity in half (half a one man show at best).

So thanks a LOT, just being able to shoot ideas off and get a knowledgeable response back is amazing thx.

I agree strange that abs light not on, wouldn't bad tone ring, bad VSS, or bad 4wABS controller cause ABS light?

light comes on when I start and goes off shortly after.

In order to stop pedal pulsing I unplugged ABS motor fuse (relay #5), light comes on at start and goes out, then after driving forward a few feet light comes on.

When I do this pedal pulse stops and ABS light stays on until next start.

I guess I can pull the rear VSS and check the tonering,

last I looked at it I thought I saw 1 notch in it but wasn't sure if that was supposed to be there (didn't look like a "chip") but after looking at pics of new rings on google they do look very uniform all the way around

 

[tjg8675]

I just spoke to my diff guy he said bad tone ring would definitely cause abs light (which I do not have)

on plus side he said I can bring him a new ring and he'll install free /emoticons/[email protected] 2x" width="20" height="20" />

+1 for Barry at the rear end shop livermore, ca

only its an hour drive away /emoticons/[email protected] 2x" width="20" height="20" />

 

[miesk5]

Yo,

Wtg Barry!

There is a way to test the VSS signal but at the PSOM. It is what a repair shop would do with just the psom.

J3 CHECK SPEED INPUT SIGNAL at PSOM IN A 96, but similar to 95

http://www.diesel-dave.com/vehic/manual/stj/stjd1017.htm#f

I assume the vss signal test could be at the vss connector with Jumpers.

I think I posted the connector diagrams on page 1.. if not see them @ http://www.diesel-dave.com/vehic/manual/stj/stjd1014.htm

http://www.diesel-dave.com/vehic/manual/stj/images/k25177a.gif

PSOM CONNECTOR

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

...

Here is more info..

RABS aka VSS Sensor Removal

Pull the wiring harness connector off.

Remove the RABS sensor hold-down bolt and remove the RABS sensor from the rear axle housing (4010).

Installation

Clean the axle mounting surface. Use care to prevent dirt from entering the rear axle housing.

Inspect and clean the magnetized RABS sensor pole piece to make sure that it is free from loose metal particles which could cause erratic system operation. Inspect the RABS sensor O-ring for damage and replace if necessary.

NOTE: Do not apply force to the plastic RABS sensor connector. The RABS sensor ****** should slide to the mounting surface. The air gap setting is between 0.127-1.14mm (0.005-0.045 inch).

Lightly lubricate the RABS sensor O-ring with motor oil, align the RABS sensor bolt hole, and install.

Install the RABS sensor hold-down bolt and tighten to 34-41 Nm (25-30 lb-ft).

Inspect the blue RABS sensor connector seal and replace if missing or damaged. Push the connector on the RABS sensor.

http://www.diesel-dave.com/vehic/manual/stj/images/h6309e.gif

Item Part Number Description

1 390356 RABS Sensor Hold-Down Bolt

2 2L373 Sensor

3 — Connector Seal

(Part of 2L373)

4 NBR017 O-Ring

A — Tighten to 34-41 Nm

(25-30 Lb-Ft)

...

Tone Ring aka Sensor Ring, Anti-Lock Speed REMOVAL AND INSTALLATION in an 8.8 @ http://www.diesel-dave.com/vehic/manual/stj/stj52g07.htm

Same as 95 Bronco

...

 

[tjg8675]

other sort of common symptoms that I do not have which I find a little strange...

do not have:

-abs light,

-flashing OD light

-hard shifts from 1st to 2nd (has always been firm here, no noticeable change from that)

-wonky odometer readings

do have:

-wavy speedo (ok from 0-25 then starts small and range of speedo waviness increases as speed increases)

-ABS engages all the time (I hear motor cycling + feel abs pulse through brake pedal)

-cruise control engages then immediately disengages (because of wavy speedo - my best guess)

-Sluggish shifts from 2nd to 3rd and 3rd to 4th (because of wavy speedo - my best guess)

going to jumper and try to get ABS codes and count the tone-ring teeth sometime in the next day or so

might get fiesty enough to take out PSOM and check the caps over the weekend...a little nervous about that tho

thanks again

 

[tjg8675]

If I recall correctly the ABS system will not retain codes once key is turned off?

Do I jumper the leads while engine running (KOER)? (after driving a bit of course)

Thanks

 

[miesk5]

Yo,

OK.

Yes, the symptoms are difficult to match with common issues.

Cluster Removal in 92-96

http://www.supermotors.net/registry/media/760981

 

[Broncoluver]

After 2 rebuilds by same guy my speedometer and odometer stopped working and tranny was shifting hard from 1st to 2nd and all around not working properly. I had a 172 code for about a month prior to this meaning problem with o2 sensor. Didn't think much bout it thought just emissions. Took to transmission shop and they replaced o2 sensor and fixed problem it was blowing fuse number 5 so the o2 sensor was shorted out. Would never thought o2 had anything to do w Speedo or transmission but it does. Hope this helps someone w same problem

 

[miesk5]

Yo Broncoluver,

Yep, stuff happens!

Btw, Fuse E is sometimes referred to as **** fuse 5 in Power Distribution Box (PDB) underhood next to air filter box.

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 GASOLINE
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.


94 PDB;

http://www.supermotors.net/registry/media/834106

Suggest that you inspect the harness. 

Al