I’ve been having some AH/TC issues lately. Upon start up I get the AH/TC warnings with the following codes:
P1571 Traction Control Torque Request Circuit
P1689 Traction Control Delivered Torque Output Circuit
SDM U1040
IPC U1040
B0432 Rear Defogger Relay Circuit*
Sometimes BO RFA U1096, 1064 & 1016

These TC codes in the beginning were only active for seconds and would turn to history . During this active time, I have no TCS comm.

These are all current but within 30 seconds to a couple minutes these will all switch to H and I have TCS comm again (except B0432).

Thanks for help

I have checked/cleaned the 2 ground connections (Took the plugs apart) on the left/right frame rails. Checked the door accordion connections and checked the ignition switch voltages at the fuses at the under hood/ipc fuse blocks and all had battery voltage.

Since it is now staying in this fault condition for longer periods of time, I tested the ignition voltages with the engine running but this time there is no voltage on IPC fuse 21 and 22. Once the TCS has comm again, I have battery voltage again on fuses 21 & 22 and the above DTC’s are now history. This no voltage/voltage at 21 & 22 is very repeatable.

Today I discovered that when I have the no TC comm, I also have no voltage at IP fuse 18 ( havoc), with the fuse in or out.

Does this still sound like an ignition switch issue? I would have expected to see lower than battery voltage at the fuses instead the no voltage/voltage.*

 

Thanks 8vette7. I have been thinking ignition switch the whole time but have been searching schematics for another possible cause. I have come up empty handed in that respect. I guess... switch...here I come!

 

I found that when the car was in the fault condition and I tapped around the key area, the condition would clear.

This is what I found


I did try some pre resistance readings before I took the switch apart but they were inconclusive. I was not going to go that far and stop any way. Near the burnt tabs, you can see arcing dust on the plastic walls.
Will not be until next weekend before I have time to clean them up and reinstall.

 

Holy CRAP Thats just about as bad as they get!

Good find and PLEASE keep the post updated on the end outcome.

BC

 

New switch installed today and all is good. Thanks to to Bill for his procedures and 8vette7 for pushing me to go for it:thumbs