1860 code...

[bricker82]

My mom's 2000 Grand Prix GT 3.8L has the 1860 code being thrown. The car has ~81000 miles on it and has had the tranny rebuilt before (around 50000 miles). She's had the code cleared and it did come back again.

Recently, she had a tranny leak fixed, which the mechanic thought was coming from the pan but it was coming from the point where the axle connects.

After she had the leak fixed, she started getting this code. Also, the Low Coolant Light was coming on and so was the Change Oil Soon Light. As I am in a completely different state...she's in MI, I'm in AZ, I can't tell you the fluid levels. She said they looked ok, and she had the oil changed on schedule. Maybe they forgot to set the light again. I was just wondering if they could possibly be connected.

My sister previously owned this car and she had to shell out $1600 when she had the tranny rebuilt! My mom doesn't have that kind of money and I was hoping that it's a relatively cheaper fix.

Any Ideas?
Brick

[BNaylor]

DTC P1860 is an electrical malfunction of the Torque Convertor Clutch - Pulse Width Modulation solenoid (TCC-PWM). When set it disables TCC operation, shift adapts and may possibly inhibit 4th gear (OD). It is either a short or an open in the TCC-PWM circuit.

If the tranny side cover was removed to fix the leak at the axle shaft (driver's side) it is possible the 20 way umbilical cable was not installed properly or the mechanic damaged the TCC-PWM solenoid. Of course, this is just speculation.

I would disconnect the 20 way connector and reseat it to start. Located at the driver's side, top of transmission below the air box.

On the low coolant indication, coolant level at the radiator should be checked not just the reservoir. Oil change light probably just needs to be reset. Looks like independent problems to me.

[maxwedge]

This code refers to a problem in the pwm solenoid or sensor in the valve body, this must be scanned by a pro with a trans function scanner for a proper diagnosis. These components control the internal trans operating pressures. Reset the oil change lite, but the interval will now be out of synch.

[bricker82]

Thanks guys, I'll relay what info I can to her.
I really appreciate it.

Brick

[BNaylor]

Originally Posted by bricker82

Thanks guys, I'll relay what info I can to her.
I really appreciate it.

Brick

You're welcome.

To make it easy for her on the oil life indicator, if she has the owner's manual just refer her to Chapter/Section 6, p. 6-19. The page will have the reset method for regular DIC and enhanced DIC.

[bricker82]

Thanks again!
Brick