Checked DR BLU wire at position E4 at pcm and there was no voltage in park. Didn't have time to check trans connector, but i will this afternoom. Shouldn't it show a code if it was not getting a signal from the trans.

 

There is no checks on the park/neutral position switch. It is just an encoder that relays the position of the shift lever to the PCM.

 

The BK BLU wire at the park/neutral position switch at bottom of steering colum showed voltage with test light in all positions. Didn't test PNK wire, but iI will check for continuity with DK BLU wire this afternoon. Didn't see the park/neutral position switch on the diagram to trace the wires for continunity. Does the DK BLU wire at the park/neutral position switch go to the trans or the PCM?

 

What I have been talking about is the range/pressure switch inside the transmission. The manual valve puts pressure to the three pressure switches depending on the manual valve position as stated in the above information. You have to have the engine running and be back probing the connection to test it. If continuity from terminal R at the main transmission harness connection (passenger side above the pan) to the ECM tests fine, and you still have no voltage to the ECM given the above conditions, then you have a problem with the pressure switch inside the transmission pan.

I have not been able to find good information about the park/neutral position switch in anything I have ever found.

 

Thanks so much for the information. I'll do some more checking and let you know what happens. I would have thought that if it was the pressure switch, the trans would not have worked even when the mechanic bypassed the computer with his equipment to check it out.

 

The pressure switch is used more for telling the PCM what position the manual valve is in than the park/neutral position switch. By setting the state with the scan tool, the pressure switch inputs were overridden.

 

I checked the DK BLU at back of PCM and there is no voltage. I checked the wire from the trans connector to the PCM connector and there was continunity so the wire not broke.

 

Have you checked for ground switching instead of power on that wire?

 

Do you mean to , hook the ground of my test light to a positive and probe the DK BLU wire to see if it is grounding and un-grounding when the trans is shifted (with engine running)?

 

this might be a long shot, but is the vehicle running at operating temperature? I know when the thermostat was bad in mine, it would not lock the convertor and engage overdrive until it reached 190f, and with the bad thermostat it wasn't.

Might just be something to check.