Troubleshooting

DTCP 0741 TORQUE CONVERTER CLUTCH SOLENOID PERFORMANCE (SHIFT SOLENOID VALVE SL)

SYSTEM DESCRIPTION

DTC Detection Condition:

The ECM uses the signals from the Throttle position sensor, Air-flow meter and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.
Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect mechanical trouble of the shift solenoid valve SL, valve body and torque converter clutch.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Torque converter lock-up is controlled by the ECM based on O/D direct clutch (input) speed sensor NC0, output speed sensor SP2, throttle position, engine temperature, transmission temperature, and gear selection. The ECM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input shaft rpm (NC0) or output shaft rpm (SP2). The ECM calculates the actual transmission gear by comparing input shaft rpm (NC0) to output shaft rpm (SP2). When conditions are appropriate, the ECM requests "lock-up" by applying control voltage to shift solenoid SL. When the SL is turned on, solenoid SL applies pressure to the lock-up relay valve and locks the torque converter clutch.
If the ECM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the ECM interprets this as a fault in the shift solenoid valve SL or lock-up system performance. The ECM will turn on the MIL and store the DTC.

Example:
When any of the following is met, the system judges it as a malfunction.
a. There is a difference in rotation between before and after torque converters even when the ECM commands lock-up.
(Engine speed is at least 75 rpm greater than input turbine speed.)
b. There is no difference in rotation between before and after torque converters even when the ECM commands lock-up off.
(The difference between engine speed and input turbine speed is less than 35 rpm.)

Step 1 - 2:

INSPECTION PROCEDURE