P0742 on Pontiac: How to Diagnose & Fix
Torque Converter Clutch Circuit Stuck On
1 Pontiac model · 1 documented issue · 1 critical
P0742 on Pontiac by model: symptoms, diagnosis and fix
The exact corpus supports 4T65-E shift and failure conditions throughout the frozen 2001-2008 range, but not one cause. Examples include P0756/P0757 shift faults, P0741/P0742 TCC paths, pressure-control and valve-body work, second-clutch shudder, V8 torque-converter conditions, slips/no drive/reverse and code-specific valve-body reconditioning (including 10025065 for 2001-2008). The frozen accumulator, clutch-pack, solenoid and pan-magnet explanation collapses distinct unit/RPO, calibration, hydraulic, electrical and mechanical paths.
Common Symptoms
- transmission RPO identified
- codes and operating conditions captured
- fluid, debris, cooler flow and pressure checked
- electrical, hydraulic, converter and clutch paths separated
How to Fix
Identify the transmission by VIN/RPO and capture codes, freeze-frame, commanded/actual gear, shift timing and temperature. Inspect fluid/debris, cooler flow and line pressure, then follow the code- and unit-specific tree before solenoid, valve-body, converter, clutch or unit replacement. Do not buy a solenoid, valve body, clutch kit, accumulator, magnet or transmission from this page; unit/RPO, failed path, calibration, part number and VIN fitment must be established first.
Sources for this issue (2)
P0742 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0742 mean on a Pontiac?
P0742 stands for "Torque Converter Clutch Circuit Stuck On." P0742 means the torque converter clutch (TCC) circuit is stuck on, meaning the lockup clutch that mechanically links the engine to the transmission stays engaged when it should release. The computer commands the clutch on and off, and when it detects the converter clutch remaining applied, it sets this code. The classic symptom is the engine stalling when coming to a stop, similar to driving a manual without pushing the clutch in, along with possible harsh shifts or poor fuel economy. It points to a hydraulic or solenoid problem inside the transmission rather than the engine. On Pontiac it is documented across 1 model: Grand Prix.
What are the most common causes of P0742?
The most common causes of P0742 are: Stuck or failed torque converter clutch solenoid, Stuck valve in the valve body (TCC apply valve), Contaminated or degraded transmission fluid, Internal transmission hydraulic leak holding the clutch on, Wiring or connector fault to the TCC solenoid, Faulty torque converter, Dirty or clogged transmission filter. The specific cause varies by vehicle.
How much does it cost to fix P0742 on a Pontiac?
Repair costs vary widely with the root cause and Pontiac model; each issue on this page carries its own estimate where one is published.
Looking for P0742 on a different make?
View P0742 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.