I have a 2000 Town and Country LXi with 3.8L that died going down the highway at 65mph. Engine
just shut off. No codes stored or pending. Now the van will only start if throttle is about half open and dies immediately if the throttle returns to idle.
Fuel pressure at the rail is 49psi
TPS sensor is 16.5% at idle position and 75.6% at WOT (scan tool)
Coil pack tested a little weak so I replaced it with a used one I had on hand.
IAC was not engaging so I replaced and now seems to function normally.
With the throttle body removed the engine starts fine but idles runs rough. I cleaned the throttle body while it was removed and I was replacing the IAC.
MAP sensor showed a constant 4.6v without any fluctuation so I replaced it. with the throttle body installed and the MAP sensor removed the engine starts but runs rough. if I plug the MAP sensor hole it dies. Replacement MAP sensor also reads constant 4.6v on the signal wire. Supply wire reads constant 5.1 volts and ground wire is good. Just out of curiosity I disconnected the the MAP sensor and checked the voltages. 4.6v on the signal wire. I cut the signal wire at the PCM and checked again still 4.6v coming from the PCM on the signal wire. with the signal wire cut from the PCM and connected to the MAP sensor I get a variable voltage in accordance with the vacuum applied. I have been unable to locate any shorts of that signal wire so I am left with the PCM emitting a constant 4.6v on the MAP sensor signal wire.
At the suggestion of a local Chrysler tech I replaced the PCM with a remanufactured unit. Still getting 4.6v on the MAP signal wire from the replacement PCM but now I also get seemingly random DTC codes: P0108(Signal wire is still cut), P0340, P0118, P0351, and a couple more I don't recall now. I have checked the wiring harness but it looks to be intact and I have not been able to find any shorts. The codes come and go without me resetting them so I am wondering if they might just be the new PCM learning the existing sensors without the vehicle actually running, but the PCM should not be sending a 4.6v signal on the MAP signal wire and yet both PCMs are doing just that... PLEASE HELP!