P0742Torque Converter Clutch Circuit Stuck On
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0742 means the converter clutch stays applied although commanded off – there is almost no slip. GM's T43 flags −50 to +13 rpm for 1.5 s six times and the 6T70 −20 to +30 rpm for 2.5 s, both after one trip; Allison and Saab's Aisin AF40 after two trips, the AF40 also when the engine stalls without slip. Typical is the engine stalling when stopping or when selecting D or R, plus jerking at low speed. Note the different uses: Ford's P0742 is a short to ground in the clutch solenoid circuit (stuck on is P2758 there), and Saab's 9-3 of 2003 uses it for a mechanical lock-up fault.
- What you may notice
- Engine stalls when stopping or selecting D/R
- Jerking or bucking at low speed
- Check engine light or transmission warning
- Likely causes
- LikelyConverter clutch control valve sticking in the applied position
- PossibleSolenoid stuck open (or short to ground with low-side control)
- PossibleLock-up clutch seized in the converter
- PossibleWrong fluid level or contaminated fluid
- RareEngine or turbine speed signal implausible
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €200 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.