View Full Version : 2000 Deville Code P1860

09-22-08, 09:12 PM
I looked up a P1860 and it says TCC PWM Solenoid Circuit Electrical

Anyone know what that means ?


09-22-08, 09:48 PM
There is a problem with the Torque Converter Clutch, Pulse Width Modulation solenoid circuit. It locks the converter to the engine to prevent slippage, increasing fuel mileage above 41 MPH. The solenoid is in the side cover. I'd start by checking the electrical connector to the trans and the wiring before anything else. To get at the solenoid, the drivers side of the cradle has to be lowered enough to get the side cover off through the wheel well.

09-23-08, 03:15 AM

10-14-13, 07:48 PM
You do not have to remove the Trans to replace the solenoid!

With Codes P1860 & P0741 its most likely the wire broke from the solenoid. In my case an engine vacuum leak caused the rpms to increase which put extra strain & pressure on the transmission while in drive, therefore breaking the wire.



10-14-13, 08:09 PM
A vacuum leak/high idle has absolutely nothing to do with wiring (and does not cause any "strain" or "pressure" on anything).

10-15-13, 06:30 PM
Yeah, that ^^^. Heat, time, and poor design are the culprits. The second YouTube - the Seville - (in Europe ??) was posted in here or Northstar earlier this spring. That transmission electrical umbilical cord is well clamped and sealed - you could darn near lift the transmission with the harness.

My solenoid let go early in the summer - at 45 mph on a level rural road cruise - I'll tackle it this fall. Rats !

If you get a P 1860 alone it's probably the solenoid; if you get P 0741 alone it's probably the TCC itself - in the torque converter - and that DOES require transmission removal.