5-speed auto problem, help please?
A plea for help from Scotland, UK.
Dodge Ram 2500, early 2004, 5.7 Hemi with 545RFE autobox and NGC controller.
So... about 4 years back my auto trans wore out. It was replaced with a remanufactured unit, shipped to the UK from the USA, and fitted by myself. I had an initial solenoid pack pressure switch fault which was repaired under warranty (new solenoid pack sent, I fitted it myself) and it's been perfect ever since.
3 weeks ago, I noticed a misfire and could hear HT "arcing" somewhere near no.3 cylinder's coil pack. Not wanting to go in there twice, I elected to just replace all 16 plugs, all 8 coil packs and all HT leads. Yesterday, I finished the job and the engine now runs smoother than ever - but I have a new, major problem.....
It drove up a fairly steep slope to the workshop door just fine 2 weeks ago, but today the trans is in limp mode, with no MIL lamp on! We've had some heavy rain this last week, but all ecu's and electrics are dry.
I have DRBIII scantool, so I had a play this morning.
One-trip fault, P0755, 2C solenoid circuit. (It will clear, but comes back as soon as Drive, 2 or 1 is selected with the engine running, fault does not re-appear when selecting P, R, or N from startup).
Unable to carry out solenoid function test due to Limp-Mode.
I've checked the electrical connections at the gearbox and NGC control module (ECU), and I'm measuring 1.7 ohms across the 2C solenoid at both the gearbox connector and the harness plug at the ECU, which is pretty much in the middle of the values I've found online of 1.3 and 1.9 ohms, so I can't see the fault being in the gearbox or wiring....
Am I looking at an ECU internal failure here? Anyone have any ideas or pointers that may help me? Please?
2003/4 2500 Quad-Cab, Hemi-powered and running on LPG.
7.5 ton electric winch, hidden behind front bumper and powered by an intelligent split-charge system with twin 130Ah batteries.
On-board air, 2.5 gallon tank and a pair of British Rail Class 55 Deltic locomotive horns... almost enough to awaken the dead!
285/70-17 Toyo Open-Country A/T tyres (excellent on ice!).
Fully equipped as a motorsport recovery unit and licenced in the UK by the MSA.