No start-Dodge Ram 96 B2500

All of those sensors didn't fail at once. All of the codes for voltage high suggests a break in the ground wire that is common to all of them. There are also four ground wires for the Engine Computer. Two of them are "signal grounds" meaning for the sensors. The other two are "power grounds" meaning they're for high-current items like injectors and the ignition coil.

Use a scanner to read live data. If all of those sensors still read high, measure the voltage on the three TPS wires. You should find 5.0 volts, 0.2 volts, and the middle signal wire will have somewhere near 0.5 volts at idle up to around 4.5 volts at wide-open throttle. If you find 5.0 volts on all three, there is an open ground wire someplace.

Caradiodoc

Perfect. That means the ground wire is open for all of those sensors. The crankshaft position sensor is on the same ground circuit. That's why the engine won't start. I only have a '99 service manual but I think it is the same. Follow the TPS wires about a foot to the larger harness that runs along the inside of the left valve cover. Follow that harness toward the back of the engine to just in front of the breather cap. There's a splice about an inch in front of where the rear injector wires go into that harness. Check there for a corroded splice. Another splice appears to be buried right over the front of that valve cover. The harness along the valve cover crosses a larger harness that goes across the front of the engine. The front injector wires appear to go into the harness right by that splice.

The last splice appears to be about a foot from the Engine Computer down that harness. The wire you're looking for is black / light blue. Before you tear the harnesses apart, see if you can back-probe the connectors at the Engine Computer. You might have to pop a protective cover off so you can stick a paper clip beside the wire to reach the terminal, but don't completely disassemble the connector body because they're nightmares to get back together. There's three rows of pins in the black connector. In one of the outer rows of pins, the black / light blue wire is the fourth one from the end. Measure the voltage there first, if possible. I think you're going to find 0 volts, but if you do find 5 volts, there's no need to look at those splices. If there is 0 volts there, that 5 volts from the sensors isn't getting back to that pin. That means there's a break in that wire between the Engine Computer and all of those sensors. The splices are the most likely places to find the problem but the wire could be cut anywhere.

Caradiodoc

Thanks bunches. According to the service manual, the three computer plugs are all different colors. You want the black one.

Caradiodoc

If you're interested in performing an autopsy, you might want to take the computer apart to see if the copper trace for that ground circuit is burned open. That happened to a "bugged" car that I put problems in for my students to troubleshoot. There was a 1/4" long circuit between two pins that fed the alternator field on a '97 Dakota. While testing the system, someone grounded the wrong point and burned that circuit open. Later I added wires to it and a switch so I could switch the defect in and out as desired. I also took a few computers apart that had that gel material surrounding the circuit board. It doesn't take too much effort to peel those boards out, then you can rub the gel off to look at the backside of the pins.

Caradiodoc