P0742 Code: TCC Stuck On — Meaning & Fix

Sun West Transmissions — Glendale, AZ. Free estimates, honest diagnosis and a 3-year / 40,000-mile warranty on qualifying rebuilds and replacements.

What Does P0742 Mean?

P0742 is the OBD-II code for “Torque Converter Clutch Circuit Stuck On.” The torque converter clutch (TCC) is supposed to lock the engine to the transmission at cruising speeds and release when you slow down, stop or accelerate hard. P0742 means the computer commanded the clutch to release, but it detected that the converter was still locked or not slipping the way it should.

This is the opposite problem from P0741, where the clutch will not lock. With P0742, the clutch stays applied when it should let go. Think of it like a manual transmission car where the driver forgets to push in the clutch pedal when coming to a stop.

Symptoms of a Stuck-On Converter Clutch

• Engine stalls or nearly stalls when coming to a stop
• Vehicle bucks or shudders at low speeds, similar to lugging a manual transmission
• Rough idle in Drive that smooths out in Park or Neutral
• Engine stalls when shifting from Park into Drive or Reverse
• Check engine light, sometimes with other transmission codes

Stalling is the most important symptom because it can affect power steering and power brake assist. If your engine dies at a light on Northern Avenue or while turning across traffic, that is a safety concern and the vehicle should be checked promptly.

What Causes P0742?

Sticking TCC Solenoid

The TCC solenoid can stick in the applied position mechanically, or be held on by a short in its control circuit. Debris in the fluid is a frequent cause of solenoid sticking.

Valve Body Problems

The valves that control converter apply and release can stick in their bores, especially when the fluid carries clutch material or metal. Worn bores can also cause unwanted apply. Our valve body repair service corrects these hydraulic faults.

Wiring Faults

A short to power in the TCC control wire, damaged connectors or a failing internal harness can keep the solenoid energized.

Converter Internal Failure

Less commonly, damage inside the torque converter itself, such as a warped clutch plate or debris, can cause the clutch to drag when it should release.

Software or Computer Problems

A computer driver fault or outdated software can command lockup incorrectly. Updates and TCM programming are sometimes part of the fix.

What You Can Safely Do

• If the engine stalls at stops, shift to Neutral as you come to a stop to keep it running, and drive straight to a shop
• Check fluid level and condition if your vehicle has a dipstick
• Avoid heavy traffic and highways if stalling is frequent
• Do not tow with the vehicle until it is repaired

Never unplug transmission connectors while the engine is running or try to bypass the TCC circuit. Doing so can cause other faults and can make the vehicle behave unpredictably.

How Sun West Diagnoses P0742

We confirm the code, check for related codes and review freeze-frame data. Using a scan tool, we command the TCC on and off and watch engine speed versus turbine speed to see whether the converter actually releases. Electrical testing checks the solenoid, control wire and connectors for shorts. If the circuit is good, we evaluate the hydraulic side, including the valve body and fluid condition.

The pan and filter often tell the story. Heavy debris suggests that a solenoid or valve is being held by contamination, and that the transmission may have other wear. You can read about our full process on the how transmission shops diagnose problems page.

Is It Safe to Drive With P0742?

If there is no stalling, short careful trips are usually possible. If the engine stalls at stops, minimize driving and get the vehicle checked quickly. Losing engine power while turning or in traffic reduces steering and braking assist. Stop driving immediately if the transmission also slips, overheats or will not engage.

Repair Options and Cost

Common repairs include a TCC solenoid replacement, wiring repair, valve body repair or reprogramming. If debris from internal wear caused the problem, a torque converter replacement or full rebuild may be the right fix. Cost depends on the vehicle and what testing finds, so call for a free quote. Qualifying rebuilds and replacements include our 3-year / 40,000-mile warranty, and financing is available.

P0742 Code FAQ

Why does my truck stall only in Drive?

In Park and Neutral the converter is not coupled to the wheels. In Drive, a locked converter connects the engine to the stopped wheels and pulls the RPM down until it stalls.

Is P0742 caused by the engine?

Not usually. It is a transmission control issue, but engine idle problems can make the symptoms feel worse.

Can P0742 come and go?

Yes. A solenoid held by debris or a heat-sensitive wiring fault can be intermittent, which is why freeze-frame data and road testing matter.