Thread: D4 GEARBOX FAULT P0928-13 GEARSHIFT LOCK SOLENOID - OPEN/CIRCUIT

Originally Posted by gregstevens67

I just checked live Data on the TCM. On off brake pedal registers with TCM gearshift solenoid inactive then active!!!. Fault further down the line.

So you’re saying that the TCM is seeing the canbus event for the pedal press and is triggering the solenoid event to activate, yet the solenoid is not activating?

Do you have the manual for the vehicle wiring? I suspect it’s switched positive and the solenoid is permanently grounded. If so, check the connection to ground is good (use continuity test/measure resistance to ground) at the solenoid plug.

I’ll look it up later on and see if I can find it in the diagrams.

Thanks Jeff much appreciated.
Yes live Data off TCM showing solenoid signal on off as I pressed the brake pedal. Was a relief to see that as was worried TCM had failed.
There are 2 yellow wires going to solenoid which #10 on plug is earth. Will check it's continuity today.

Diagram below. Seems both ends go to the ECU. Might pay to investigate the P-Lock Confirmation sensor in case the sensor that I presume senses the solenoid state is an issue?




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Originally Posted by DiscoJeffster

So you’re saying that the TCM is seeing the canbus event for the pedal press and is triggering the solenoid event to activate, yet the solenoid is not activating?

Do you have the manual for the vehicle wiring? I suspect it’s switched positive and the solenoid is permanently grounded. If so, check the connection to ground is good (use continuity test/measure resistance to ground) at the solenoid plug.

I’ll look it up later on and see if I can find it in the diagrams.

I checked the actual 2 pin plug on the back of the solenoid and it has a reversed polarity of 5v plugged in, made no difference on the brake pedal in/out.
There was no continuity between yellow #10 neutral to earth.

Also live data showed

In park: tcm "P" Transmission 3rd

In reverse: tcm "R" Transmission R

In neutral: tcm "N" Transmission 3rd

In drive: tcm "D" Transmission 3rd

Guessing this is because of the limp mode, stuck in 3rd?

Hey Jeff, Where abouts is the park sensor located?

No idea. I just read the wiring diagram and considered it a possible factor

Hi Greg,

The "park sensor" (P-Lock confirmation) on the wiring diagram, looks to be a confirmation input back into the transmission. That would mean the Transmission gets a positive notification that park has been selected and locked, and this shouldn't be an issue for this fault.

Given that all gear selections are reporting 3rd gear selected it looks more like a TCM issue in the gear box.

If you can clear all fault codes in the transmission, I would then go for a drive using the shift lock release button and see what gear/s are available in drive. I would not expect a shift lock solenoid to cause limp mode (unless there are other fault & fault codes in the system).

Lastly, I expect the system to monitor the solenoid by sending a few volts across it but not enough to activate it, that is why you are seeing a voltage when its not active.

Cheers
Marc