P0742
DTC P0741: Torque Converter Clutch System (Stuck Off), P0742 Torque Converter Clutch System (Stuck ON)DESCRIPTIONS OF MONITOR METHODS
^ When the input shaft speed sensor is normal, the engine speed signal is normal, and within the lockup operation range, the slip speed of the torque converter exceeds the specified value. (P0741)
MONITOR EXECUTION
^ Continuous
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
^ Not applicable
Sensor (The sensor below is determined to be normal)
^ Not applicable
LOGIC FLOW CHARTS (Monitor Sequence):
DTC SET CONDITIONS
Check Conditions
^ Solenoid status: plunging into connecting condition.
^ Crankshaft position sensor: normality.
^ Input shaft speed sensor: normality.
Judgement Criteria
^ Calculated slip (engine speed - input shaft speed): (40 +
OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 100 km/h (62 mph) for 10 seconds. Then stop the vehicle, and turn OFF the ignition switch. After that, restart the engine, and drive again at 100 km/h (62 mph) for 10 seconds.
DESCRIPTIONS OF MONITOR METHODS
^ When the input shaft speed sensor and the output shaft speed sensor are normal at the "D" range, the engine speed signal is normal, and within the non lock-up operation range, the extremely low slip speed of the torque converter is detected continuously for a specified time. (P0742)
MONITOR EXECUTION
^ Continuous
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
^ Not applicable
Sensor (The sensor below is determined to be normal)
^ Not applicable
LOGIC FLOW CHARTS (Monitor Sequence):
DTC SET CONDITIONS
Check Conditions
^ Output speed: more than 1,000 r/min.
^ Solenoid status: 5 seconds after not plunging into connecting condition.
^ Transmission range switch position: D.
^ Input shaft speed sensor: normality.
^ Output shaft speed sensor: normality.
Judgement Criteria
^ Calculated slip (engine speed - input shaft speed): 5 r/min or less. (5 seconds)
OBD-II DRIVE CYCLE PATTERN
Start the engine, and drive at 30 km/h (19 mph) for 30 seconds. Then stop the vehicle, and turn "LOCK" (OFF) the ignition switch. After that, restart the engine, and drive again at 30 km/h (19 mph) for 30 seconds.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the P0743: lock-up and low-reverse brake linear solenoid valve system circuit
^ Malfunction of the P0712: transmission fluid temperature sensor system (short circuit)
^ Malfunction of the P0713: transmission fluid temperature sensor system (open circuit)
^ Poor installation of the engine and A/T (deviation to the axial direction)
^ Malfunction of the torque converter
^ Malfunction of the valve body assembly
DIAGNOSIS
STEP 1. Hydraulic pressure test
Hydraulic Pressure Tests
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair or replace the failure section.
STEP 2. Check the lock-up and low-reverse brake linear solenoid.
Check for P0743 (lock-up and low-reverse brake linear solenoid). P0743
Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair or replace the failure section.
STEP 3. Check the transmission fluid temperature sensor, input shaft speed sensor, and output shaft speed sensor.
Check the following DTCs: P0712 (transmission fluid temperature sensor (short circuit)), P0713 (transmission fluid temperature sensor (open circuit)), P0715 (input shaft speed sensor) and P0720 (output shaft speed sensor).
P0712
P0713
P0715
P0720
Q: Is the check result normal?
YES: Go to Step 4.
NO: Repair or replace the failure section.
STEP 4. Check the malfunction of CAN communication system.
Q: Are the DTC for CAN communication system malfunction (U0001, U0100, U0141, P1705, P1706) set?
YES: Repair or replace the failure section.
NO: Go to Step 5.
STEP 5. Check the TCM connector pin terminal and the connection status.
Q: Is the check result normal?
YES: Replace the TCM, and then go to Step 6.
NO: Repair or replace the failure section.
STEP 6. Erase the DTC code, and drive the vehicle for a while.
Check that the normal code is displayed.
Q: Is the check result normal?
YES: The procedure is complete.
NO: Go to Step 7.
STEP 7. Check the installation position of the engine and A/T.
Q: Is the check result normal?
YES: Replace the transaxle assembly.
NO: Repair or replace the failure section.