Description & Operation
A drive cycle is a pattern of driving in which the ECM will execute all OBD-II diagnostic monitors. A drive cycle can be used to cause a DTC to set if fault is present or to verify a DTC will not return after a repair has been done. The drive cycles consist of 3 different driving patterns. When a pattern is successfully completed it is called a "trip". Ensure pattern "A" is completed before attempting to perform patterns "B" and "C". Drive cycle trip status can be observed using OBD-II scan tool. Access DATA MONITOR menu selection and select TRIP SET from scan tool menu screen.
System Description
The ECM controls torque converter clutch solenoid valve to cancel the lock-up condition of A/T. When the solenoid valve is turned on, lock-up is cancelled. When the solenoid valve is turned off, A/T lock-up is operational.
Conditions for lock-up cancel
- Throttle valve is fully closed (idling or deceleration)
- Engine coolant temperature is below 60°C (140°F)
- Vehicle speed is less than 64 km/h (40 MPH)
- During high-load operation
| Diagnostic Trouble Code No. | Malfunction Is Detected When | Check Items (Possible Cause) |
|---|---|---|
| P1550 0904 | An Excessively Low Voltage From The Solenoid Is Sent To ECM Or A/T Torque Converter Slip Is Occurred In Lock-Up Condition. | Harness Or Connectors (The circuit is open or shorted.) Or Torque Converter Clutch Solenoid Valve Or A/T Hydraulic Control System |
TORQUE CONVERTER CLUTCH SOLENOID VALVE
See also:
• WIRING DIAGRAMS