jibbinc.Truck is giving me tranny problems
runs ok when its cold. once its warm, starts to shift rough. and if i turn it on and off, O/D light flashes and tranny goes into limp mode. ( shifts 1st 2nd neutral, stuck at 50km/h)
its a 97 ford f 250 7.3l diesel
Got it scanned
p0236 Turbo Boost Sensor A Circut Performance
p0708 Transmission Range Sensor Circut High
p0713 Transmission Fluid Temperature Sensor Circut High
My truck has always had a voltage fluctuation. goes from 11.5 - 14v constantly. Unless above 1300rpm.
The lights dim and get brighter the battery gauge goes up and down, the idle moves SLIGHTLY. barley noticeable.
From my reading it could be something with the PCM wiring harness. Doesn't seem like the sensors are blown, they are just getting incorrect voltage. Which i think is linked to my fluctuation problem.
I dont want to start getting random shit fixed. Would rather get 4 birds stoned at once.
It is hard to say, but a turbo fault is most likely not related to transmission faults. It could be but I am not too sure of how the limp mode in a ford diesel works but there are completely different control units. Turbo circuit faults could be a million different things from a boost leak, over boost, no boost, vac leaks, faulty turbine in turbo, wastegate issues... etc etc so its really hard to guess on what your turbo related fault is.
The first thing i would do is pop the transmission harness connector off the transmission if possible and look for corrosion on the terminal pins of the connector. Also, check to see if gear oil has soaked the terminal pins, I have seen some kooky shitty from gear oil soaked wiring harness connectors due to the capillary effect... the seal of the harness inside of the transmission could be leaking and allowing gear oil onto the terminals... when electricity is applied it actually draws the oil out of the gear box on the wires... I have seen it come all the way to the TCM/ECM.
that is a good starting ground.
Typically transmission fault codes are not cureable with basic parts, most of the time it is either a valve body or gearbox failure if you can confirm the electric control circuit is ok. If your voltage is jumping, that sounds like a bad ground or corrosion in the wiring somewhere, it could be very tricky to track down.