Generic Fault Code
Free · no signupP0744
TCC Lockup Drops Out Randomly at Cruise
System
Transmission
Symptom
TCC Lockup Drops Out Randomly at Cruise
Diagnosis & fix steps
LOGIC: Torque Converter Clutch Circuit Intermittent.
ACTION: Clean case plug terminals. Check wire pin contact seating security inside internal trans wiring ribbon assemblies.
Red Seal field insights
Intermittent Logic: Worn lockup circuit wiring traces cause periodic open connection drops during trans housing vibration shifts.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
Track this across your whole fleet
This code is free to read. AM Fleet Integrity lets your team log fault codes against assets, plus the full fault-code library, QR operator reporting, PM scheduling and predictive alerts. Start free — no credit card required.
Start your free trialRelated Generic fault codes
- P0745Harsh Shifts / Max Line Pressure / Clunking
- P0743Trans Warning Active / TCC Inoperative
- P0746Soft Slipping Shifts / Burned Clutch Packs
- P0742Engine Stalls Dead whenever Shifting to D or R
- P0747Extremely Harsh Shifting / Solenoid Locked
- P0741TCC Solenoid Energizes but Slip Persists
- P0748Trans Warning Active / Default Line Pressures
- P0740No Fuel Economy Lock / Tachometer High Cruise
- P0749Shift Quality Fluctuates Wildly
- P0736Engine Revs but Vehicle Refuses to Back Up