01 dodge speedo doa

[Mopar1973Man]

PCM has nothing to do with it. ABS and the Gauge Cluster. AC noise doesn't bother the sensors but it fries the computers like ABS computer or maybe the gauge cluster. But there is the cluster test to check for errors. Hold the trip down turn the key to ON and the CHEC shows in the odometer release the trip pin. This goes back to the same problem of guys replacing VP44's one after another with electronic failures. It stems from a bad alternator cooking the electronics.

 

As for speed signals. The ABS module reads the rear sensor and then transmits the data of CCD netowrk for any device to use. As for speed the PCM does use the speed for cruise control but has no bearing on the cluster. Which the cluster is a stand alone computer than listens for data on its own.

 

I just had a guy call about VP44 that lasted barely 9 months and fried. Then come to find out he's got the tin foil leads, modified APPS grounds, noise filter, etc. I told him to ditch all the junk and then test it out again sure enough the alternator was nearly 0.1 volt AC. Also the torque converter lock/unlock problem returned. So, just because of band-aid for the lock up issues he's now eating the VP44's which is now going to cost him most likely because it wire tapped.

 

So moral is... Make sure you go clean power to your electronics and they will have a long and happy life. Just like buying a quality surge protector for your PC at home.

[JOHNFAK]

PCM has nothing to do with it. ABS and the Gauge Cluster. AC noise doesn't bother the sensors but it fries the computers like ABS computer or maybe the gauge cluster. But there is the cluster test to check for errors. Hold the trip down turn the key to ON and the CHEC shows in the odometer release the trip pin. This goes back to the same problem of guys replacing VP44's one after another with electronic failures. It stems from a bad alternator cooking the electronics.

 

As for speed signals. The ABS module reads the rear sensor and then transmits the data of CCD netowrk for any device to use. As for speed the PCM does use the speed for cruise control but has no bearing on the cluster. Which the cluster is a stand alone computer than listens for data on its own.

 

I just had a guy call about VP44 that lasted barely 9 months and fried. Then come to find out he's got the tin foil leads, modified APPS grounds, noise filter, etc. I told him to ditch all the junk and then test it out again sure enough the alternator was nearly 0.1 volt AC. Also the torque converter lock/unlock problem returned. So, just because of band-aid for the lock up issues he's now eating the VP44's which is now going to cost him most likely because it wire tapped.

 

So moral is... Make sure you go clean power to your electronics and they will have a long and happy life. Just like buying a quality surge protector for your PC at home.

Gothcya.

Cluster check was fine.

Well thats interesting then .........so if I understood right (AC noise aside as I have no indications of this with transmission since new alternator)

 

Signal goes to ABS and then can be used by other devices (cluster for speedo signal and ABS light .......... and PCM for cruise) via CCD.

So If Im getting no signal on ALL sensors ........ its unliekly to be a wiring issue .......... so then most likely purely an ABS issue.

Most importantly there is NO PCM issues ....... as the speedo and ABS would still work fine as they are picked up seperatelty.

 

Basically - between what your saying and the diagnosis so far - its 100% the ABS module ??

 

FYI -  I sent it back to the rebuilder today anyway

[Mopar1973Man]

It still can be a ABS module issue or sensor wiring issues.

 

25 No signal drivers side sensor ABS

26 No signal passanger side sensor ABS

27 Intermittenet signal rear sensor ABS

28 No signal rear sensor ABS

 

So Verify your wiring again. If it ohms out correctly then the ABS module is to blame. Also ohm the sensors out and see if they are working properly.

[JOHNFAK]

Thanks mike.

[JOHNFAK]

So OHM the wires to speedo and everything checks.

Had the module sent back - they said it repaired and benched tested fine - but wouldn't say what. I think they just replace internal resistors/capacitors etc and check for electrical signal etc.

No difference. No signal from all 3 sensors , brake light on , no speedo.

 

I think the only way I will truly isolate if its an ABS module issue is to send it to someone with working truck and have them swap out and test.lSo anyone with a 99 or 2000 truck with 4W ABS and 3.53 gears that would be happy to help ?? I'll ship and will obviously cover return shipping also.

 

4 bolts - then take it off ..... put mine in and take for a drive. Only cautionary piece is be careful on taking the 4 bolts out to make sure they don't brake - eg no handtools - do by hand.

 

thanks !!!

[JOHNFAK]

*bump*

 

 

So anyone with a 99 or 2000 truck with 4W ABS and 3.53 gears that would be happy to help ?? I'll ship and will obviously cover return shipping also.

4 bolts - then take it off ..... put mine in and take for a drive. Only cautionary piece is be careful on taking the 4 bolts out to make sure they don't brake - eg no handtools - do by hand.

 

[JOHNFAK]

So its definitely the EBCM/ABS module. I put the old core back on from before and everything works 100% except for speedo only kicks on after ~20mph. Unsure on that one.

 

Its off to another rebuilder - will see.

 

 

Anyway to pull the original ABS part # based on VIN ? They vary.

[JOHNFAK]

FYI

I replaced the faulty EBCM with a junk one ..... the same one that was 'bouncy' before.

All of a sudden it worked. Then 2 days later I see rear diff fluid. Heres short version of what I worked out.

 

The sensor fully seated in round 1 attempt was throwing off the voltage somehow. Hence wonky speedo.

When I put it back on for the nth time ....... I accidently put the metal bracing tab from the brake lines between the sensor and the diff and tightened 9/16th bolt down. What this did was rase the sensor UP a couple of mm ... and speedo voltage now worked. But prevented a seal and diff fluid leaked.

 

So ....

 

I added a 2nd oring... and placed a thin washer inbetween ..... and sealed up with gasket maker to be 2x sure. Now all of a sudden have a working ABS module.

 

The original even after being to 2 companies - 2x was not working ....... its back again for 1 final try.

 

thought Id update.

[JOHNFAK]

ok - so I have left this for a bit (with the following upates) Sent off ABS module to another builder- Rebuilt 2x and still trips all lights and leaves speedo dead. Truly thinking the OEM module is toast. Even thought it tests ok at builder.

As soon as I put the "junker" module back on - I get speedo above 25-30 mph and brake light goes off.

 

I retested wires - 0.000003 OHM on closed circuit no sensor.

With sensor in around 1900 OHMS (1.9k).

I have tried 3 sensors in totoal (original, Chinese version, OEM version).

** I have noticed that I have to place a small washer between the sensor and the diff for it to register properly above 30mph. --- just an observation

 

So today I pulled the rear diff. The fluid was pretty bad to be honest. I noticed a couple of things and unsure if normal.

 

1) The teeth at certain part of the gear ring look flattened or different to rest - this normal ?

2) The same ring is quite offset to the driver side - where it only passes on the very edge of the sensor. I am sure its normal -but don't know.

 

Basically this is my last stop check/recheck of findings - it goes to a shop this Friday.

 

PIcs below .....

 

http://i1059.photobucket.com/albums/t430/fakdaddy/truck/20150905_151608.jpg

 

http://i1059.photobucket.com/albums/t430/fakdaddy/truck/20150905_151623.jpg

 

 

 

http://i1059.photobucket.com/albums/t430/fakdaddy/truck/20150905_152901.jpg

 

 

Seem normal or ???? *shrug*

Edited September 5, 2015 by JOHNFAK

[bjytech]

its been a while since I've had my diff cover off but I'm pretty sure the tone ring teeth are supposed to be squared, it looks like your's got wore down pretty far against something at some point, it should also be fairly centered in the hole for the sensor to get a good reading.

Edited September 5, 2015 by bjytech

[JOHNFAK]

Bjyteck ..... thanks

Sort of what I was thinking too .... been over 2 years since last had diff off ..... old truck before this one.

Was suprised to see the the condition of the fluid as well as the tone ring.

Anyone know what's involved to replace ?

Anyone can snap a pick of their teeth position through top sensor ? Want to see if I have alignment issue also.

Thx

[bjytech]

Well I just tried to take my sensor out to get you a picture but it's stuck in there pretty good so I just left it alone before I broke it.

[JOHNFAK]

Thx man I appreciate the effort ...... think I need to work out why the tone ring gear is damaged ...... just wanted to see how far out of alignment it was

[Mopar1973Man]

I think you have bearing failure of the carrier. The tone ring should be center of the hole. I imagine there was a lot of metal in the lube when you dump it out right? You'll have to pull both axle shafts and then you can check carrier bearing play. I'm going to bet money the bearings are lose.

[Royal Squire]

Almost looks like the tone ring isn't on carrier square. Like it has shifted to the left

[JOHNFAK]

I think you have bearing failure of the carrier. The tone ring should be center of the hole. I imagine there was a lot of metal in the lube when you dump it out right? You'll have to pull both axle shafts and then you can check carrier bearing play. I'm going to bet money the bearings are lose.

Not much metal really ......

So is that where the tone ring gear teeth should align ? The center of hole ?

If that's the case then yes somethings happened with one of the bearings to be that far out of alignment .....

Crap

[JOHNFAK]

Almost looks like the tone ring isn't on carrier square. Like it has shifted to the left

Yeah .... if mikes right and it should be center if sensor hole .... then quite a bit. I thought it had shifted but didn't think it was that far ....

[bjytech]

I don't think you have a bearing problem, I think the tone ring just moved out of place, after looking at some others the tone ring should be right up against the ring gear, but from your pictures it looks like it has a pretty good gap there. If you had a bearing problem it would be seen on the ring an pinion gears not the tone ring. The tone ring is just pressed onto the carrier from what I see.

[Royal Squire]

A much better way of explaining what I was trying to say

[JOHNFAK]

Thanks guys even though its just pulling the C clip and the chuck and axle I'll probably take it to a shop would feel more comfortable with them checking clearances and other issues ......

Hope its just this .....