Speedometer, odometer do not work?

Hello,

It sounds like the PCM went bad but to be sure lets do a wiring check between the VSS and the PCM. Here is a guide to help us and the engine and transmission wiring diagrams so you can see how ti works and which wires to test. Check all fuses as well.

https://www.2carpros.com/articles/how-to-check-wiring

If the fuses and wiring checks out I would try a used/rebuilt PCM. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Cheers, Ken

Please do.

Is the VSS sensor OEM? I would install the old one if not. Cheap sensors can make the needle bounce. It does sound like the fuel level sensor for the fuel gauge issue. To confirm the issue remove the fuel gauge wires and ground it, (yellow and white wire).

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help

Cheers, Ken

The truck ran all right until it snowed, could soem wires have gotten wet and shorted. Check the battery connections and clean if needed. Also check the ground wires. Some look all right but are not getting a good ground. With everything stopped working after the snow, that what I would think happened, I don't see why the transmission, the door locks, dome light, and speedometer would stop all the same time unless something happened to the electric. Make sure the fuses are good after checking the connections. There should also be a fuse box by the front fender under the hood.

The vehicle speed sensor is located on the differential housing in the middle of the third member. Here is a guide to help you see what I am talking about.

Check out the diagrams (Below)

Please let us know what happens.

Cheers

Check the fuses to make sure, but your first guess is mine too. If the check engine light came on, have the computer scanned to determine if there is a code relating to the trans. If there isn't a light, check to see if there is power to the speedo / odometer. If there is no power, start tracing wires back to the pcm to see if anything is disconnected, corroded, or damaged. You may actually want to start at the VSS to see if there is power there and trace that back. It will save time. There is one other thing you need to check. Under the dash (behind the fuse block) is a module known as the GEM. On many of these model year vehicles, the windshield would leak (not enough for you to see) and get the GEM wet and eventually cause it to short. Check the module for any evidence of water getting to it. One last thing, if you haven't, you may want to try a different VSS. With all the importing of products from other countries, there is a chance you got a bad one. It happens more than one thinks.

Good afternoon,

Do you have a scan tool to be able to read what the ECM sees from the speed sensor?

That would be the way to tell if you have a vehicle speed sensor issue or a dash cluster issue.

The sensor sends a signal to the ECM and then the ECM sends that signal to the dash cluster.

Roy

PURPOSE
The Programmable Speedometer/Odometer Module (PSOM) provides a vehicle speed signal input to:
- Powertrain Control Module (PCM)
- Speed Control Servo Amplifier
- Instrument Cluster

The speed signal is used by the PCM to determine transmission shift points and torque converter clutch operation.

OPERATION
The PSOM receives a vehicle speed signal from the Differential Speed Sensor (DSS) on pin 4 DSS input, and pin 5 DSS return. It converts this signal to a standard 8000 pulses-per-mile speed signal output. This output signal is sent to the PCM on pin 3 PSOM (+) and pin 6 PSOM (-).

The PSOM receives two power supply inputs. Pin 1 receives a continuous 12.0 volt input while pin 2 receives a 12.0 volt input only when the ignition switch is in run.

RELATED DIAGNOSTIC TROUBLE CODES

DTC 29/452 PCM detected an error in the PSOM output signal.

The Vehicle Speed Sensor (VSS) is located on the rear axle housing.