Code PO742

[TerrblT]

Hi, Anybody know a quick temporary fix for this problem. Also would like to find white high intensity headlights. 1996 Grand Prix SE 3.1

Thanks,
TerrblT

[BNaylor]

I'm assuming you have a 4T60E tranny. That should be torque convertor clutch (TCC) stuck on. The PCM sends a hi or lo to the TCC solenoid. Lo means on and hi is off. 12v is on the other side of the solenoid coil when the car is running.

I don't know of any quick fix other than getting the TCC or TCC-PWM solenoids replaced. Have you tried replacing the ATF and screen filter and adding an additive such as Sea Foam or Lubegard?

I recall someone in the past mentioned disconnecting an electrical plug to the tranny but that will affect all shifting and the fluid temperature sensor so it is not recommended. If you have access to a wiring diagram you can troubleshoot the problem with a multimeter. Good luck!








Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[maxwedge]

A bidirectional trans capable scanner can command the solenoid on and off to confirm its operation, this is the most definitive test for that circuit. Most trans shops will have this equipment.

[BNaylor]

Here's the test procedure and parameters for DTC Error Code 0742 for a 4T60E tranny using a GM Tech II:








Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.