P0740moderate severityPowertrain
Torque Converter Clutch Circuit Malfunction
on 1996 Mazda B3000 3.0L V6 · FWD
What this code means
Malfunction in the torque converter clutch (TCC) solenoid circuit.
Symptoms
- Check Engine Light
- No lockup feel (higher RPM at highway)
- Poor fuel economy
- Transmission overheating
Common causes
- Faulty TCC solenoid
- Wiring issue
- PCM driver failure
- Torque converter failure
Diagnostic steps
- Test TCC solenoid resistance
- Check wiring
- Command TCC engagement with scan tool
- Monitor RPM drop during lockup command
Repair notes
Replace TCC solenoid or repair wiring. Solenoid is often inside transmission.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1