Transmission

Those only have meaning to the person who is going to rebuild the transmission. I have a Chrysler DRB3 scanner for all of my vehicles, and I have the optional pressure test adapters meant mainly for transmission work, but I have never used them in the eighteen years I have had it. What you need to know is the diagnostic fault code numbers. You will need to find a mechanic with a scanner that can access the transmission computer, (EATX). As long as you have that connected, you can also read the "clutch volume index", (CVI). That is a set of four numbers corresponding to the volume, in CCs, of fluid it takes to apply each clutch pack. If you visit a transmission specialty shop, based on those numbers, an experienced mechanic can tell you the percent life left in each of those clutches. If any one of them is near the maximum, it is a good bet you will have a fault code related to "incorrect gear ratio", meaning slippage is taking place in one of those clutch packs. As best as I can recall, it seems to me "80" was the highest number, at which the fiber plates were totally worn away, but if anyone tells you differently, believe them, not me.

The only code is 43 od circuit failure.

OD Solenoid Circuit - Code 43

For that, you are going to find a defective solenoid pack about ten percent of the time, a defective driver circuit in the transmission computer perhaps five percent of the time, but much more commonly, a problem in the ground wire for that solenoid running between the solenoid pack and the computer. In particular, look at the connector terminals for signs of corrosion or a spread terminal.

When you hear that buzzing or ratcheting sound when you shift into drive or reverse, and when coming to a stop, the computer is pulsing the solenoid valves to modulate pressures for best shift feel, and it tests the valves at that time. When a solenoid turns off, its collapsing magnetic field generates a voltage spike. The computer looks for that spike to tell when the solenoid is working. In addition, it monitors the pressure in the appropriate circuit to see if the expected change took place. If it sees that expected voltage spike but not the change in pressure, it knows the solenoid/valve is not working, and it sets a different fault code than what you found. When it does not see that voltage spike, it knows the electrical circuit related to that solenoid has a problem, and there is no way it can expect to see the pressure change, so it does not set a fault code related to the pressure. It only sets the code related to the electrical circuit.

You can try to test the circuit for continuity from the connector at the transmission computer if you can figure out the wires. Be careful when sticking probes in the cavities. Most meter probes are fat enough to stretch the terminals so they make no or intermittent contact. The twelve volt feed wire to the solenoid pack is red. The ground return wire for the overdrive solenoid is brown. As I recall, each solenoid should measure somewhere around 8 to 20 ohms. Your meter's leads will add a good two to five ohms. If you find a good reading, watch the meter for a change when you flex the wiring harness and wiggle the plug on the solenoid pack. If you find an open circuit, remove the plug on the solenoid pack, then measure between the two terminals in the pack that correspond to those two wires.

I had a new aftermarket tcm so i hooked it up and now it shifts correctly. Could i be that lucky.

Yes, it is possible, but if it were me, I'd suspect I had disturbed the wiring harness and a corroded splice or connector terminal, or something like that. Lets see if the problem returns. I'll keep my fingers crossed.

It returned 3 trips (4 miles) later at start up. Damn the luck. Im going to check what you suggested and ill get back to you.