can the tcu affect the ecu?

[turbo970]

well i'm going to try a tcu the shop put in a new ecu and still have the same issue. my question is IF theres a bad tps circuit in the tcu COULD that affect the ecu's tps readings? my car shifts at the right mph but not the right rpm. i drove to the store and the car was reading 3500 rpm at 20 mph. its going back to the shop again tomorrow to recheck the tps wire loom.

[Legacy777]

The TPS wiring splits and goes to both the ECU and TCU. Unless there is a short in the TCU specific wiring, then I don't believe the TCU would affect the ECU, however I would certainly suggest checking the wiring from the TPS to the ECU and TCU if it hasn't already been done.

[turbo970]

they are going to check that tomorrow. the tcu is the only thing not replaced. and its binding on t he slightest turn. and if if my research is correct the duty c solenoid reads off the tcu. so if the the tcu isnt getting the proper signal from the tps then it would mess with the shifting ? in theory

[Legacy777]

Yes, if the TPS reading is incorrect it could affect how the TCU controls the shifting.

[turbo970]

so in theory its has to be in the wiring or tcu or both. because the idle is till high even with the tps set to specs. so if teh tcu circuit for the tps was fried would that cause the idle be way high?

[Legacy777]

It really depends....if there is a short in the TCU wiring and it's affecting the readings going to the ECU, then yes it could affect it, but without testing both and checking both sets of wiring for continuity and for shorts, I couldn't say for sure.

[turbo970]

i know just wondering if it could be a possible theory.