GrumpyTroy

Hello,

I'm running at a bit of a loss for what to do, so I'll give you what information I have and maybe someone can help point me into right direction.

I bought a 1993 Ford F150 XL Flareside with an E4OD and 5.0L V8. It's a basic truck, no a/c or 4x4.

The odometer displays, but doesn't change/go up. Speedometer not working. Transmission shifts hard. Later discovered that the ABS light was on, but didn't notice it before b/c the previous clown working on it unplugged part of the socket on that side of the cluster.

So, I replaced the ABS speed sensor in the rear differential with a new one. (Broke the old one off in three pieces, what a pain in the *** getting it out.) Removed the instrument cluster, took it all apart, cleaned all the connections, lights, electrical backing, and inspected the PSOM, everything looks good. Start the engine and the ABS light will go out, but come back on a second later, solid. Speedo/Odo still not working.

Checked the OHM on the socket going into the ABS speed sensor while the truck was running. Depending on which socket I put the probes in, I got either 0.61 at 20M or 0.42 at 20M.

So, I'm not sure where else to look or check. I don't have an CEL, but I pulled codes through the KOER test.

I may not have done the test right, but this is what I got.

The engine cycled through, then the light flashed 4 times. Stopped. Then it flashed once. Stopped. Then it kind of did a quick repeated flash, then started to give me the following codes:

311 - AIR system not working - Single, Right or Rear HO2S Air Injection.
536 - Brake On Off open or shorted to ground.
538 - System did not receive "goose" test.
632 - E4OD - Transmission Control Switch (TCS) should be cycled once between engine ID and Goose test.

It's possible that someone changed out the PSOM on the cluster already, someone did a hack job taking things apart and using screws that weren't factory and a few other things that look like they attempted to fix it.

It starts fine, uses more gas than it should at the moment... but I'd like to get the speedo/odo working and see if that fixes the ABS issue and at least keep the tranny from slamming into gear.

I did go over this site and another, but I'm not sure what else to check before replacing the PSOM completely to see if that works.

EDIT: I was doing a bit more reading, and found that the KOER may not be accurate or give "false positives" I suppose, so I followed the KOEO test and got these codes.

Quick repeated flash.

552 - AIRB solenoid/circuit failure.

The 552 code came up twice in a row, then the CEL flashed once and the following codes were given:

172 - Oxygen sensor not switching – system is or was lean – Single, Right or Rear HO2S
452 - Vehicle Speed Sensor (VSS) problem.
542 - Fuel pump open, bad ground or always on.

Thanks.

Chris_1

iTrader: (1)

There's an ABS module behind the glove box. Black box, 2 7 mm screws. That may be causing problems.
Try one from a different truck (wreckers). I haven't seen any difference in the 92 to 96 ones.
But in the speedo circuit you have the vss on the diff, the speed sensor on the trans, the rabs unit on the frame, the rabs module behind the glove box, and the cruise control.
Plus the fuse, which is the same one as your interior light.
Those are places for you to look for a problem anyway.
Codes are quite possibly unrelated to the speedo not working.

GrumpyTroy

Thanks, I'll take a look at those. I'm more concerned about the speedo not working; don't want to drop my tranny... I'm getting too old to be wrestling on the ground with a 600lbs piece of steel.

I did check all the fuses as well, both in the cab and under the hood. Don't have cruise control, so at least I can write that one off as causing a problem.

I suspect some of the codes are b/c the coffee can is rotted; didn't notice it until I was poking around the engine and accidentally bumped it. Hopefully I can just make a replacement instead of hunting down a new one.

GrumpyTroy

It's warmed up a bit since I last posted about this and I'm still having problems with the speedo/odo not functioning.

So far I've replaced the instrument cluster and that didn't fix the issue. There's power going to the cluster, since I can run the test and have all the needles move.

I replaced the RABS behind the glove box. When I started the truck, I heard a loud click/pop coming from that same area.

I tried to pull the ABS codes, but wasn't able to get it to work the way the instructions online suggest that it should. It still stays off for a second or two after start up then comes on solid.

I couldn't find the RABS on the frame, so if someone could possibly point out where it is or even what it looks like, that would be helpful in finding it. I don't have cruise control.

Whomever owned the truck before me didn't bother changing any fluid and considering the tranny fluid is grey/black, it's been in there for a while. Would the filthiness of the fluid cause the sensor in the transmission to fail? I'm going to get the tranny flushed and a filter change and was contemplating just changing out the sensor completely.

Anywhere else I should look?

CMERR

The RABS unit on the frame is under the cab on the drivers side almost straight down from the master cylinder. i would say its about the size of a redbull can.

Chris_1

iTrader: (1)

Follow the rear brake line from the master cylinder down to the RABS. Pretty much under where you put your feet.

GrumpyTroy

I found the second RABS module, couldn't really tell much, but at least I know where it is.

I did manage to pull the ABS code; once I figured out I was attempting to get them from the PSOM cable that was just hanging there. :o

The ABS light blinks eight short and one long; so I believe that's 9, which from what I found comes out as:

9=high sensor resistance

From what I've found, it sounds like I'm heading back to the VSS in the rear end?

I previously checked the OHM on the socket going into the ABS speed sensor while the truck was running. Depending on which socket I put the probes in, I got either 0.61 at 20M or 0.42 at 20M.

At this point, I'm not sure.

GrumpyTroy

Chris_1 had mentioned in another post that the VSS wiring was a problem area. Thanks for the suggestion. I looked it over and found a spot that looked a bit mangled. When I tugged a bit, it broke apart and the two wires had been "cut".

Spliced them back together; ABS light is off, speedo/odo are working again!