P0740

TECHNICAL DESCRIPTION
- When a malfunction of the torque converter clutch or its related system is detected, the transmission control CPU (incorporated in the powertrain control module) sends a malfunction signal to the engine control CPU (incorporated in the PCM).

DTC SET CONDITIONS

Check Area, Judgment Criteria
- Failed signal of the torque converter clutch or its related system is sent to the engine control CPU from the transmission control CPU. Both CPUs are incorporated in the PCM.

TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Torque converter clutch or its related system failed.
- Open or shorted torque converter clutch solenoid circuit, or loose connector.
- PCM failed.

DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)

CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.




STEP 1. Using scan tool MB991502, read the A/T diagnostic trouble code (DTC).
If the A/T-DTC is output, refer to Trouble Code Descriptions Chart. Testing and Inspection

If the A/T-DTC is not output, it is suspected that an MFI-DTC has not been erased after repairing the A/T component.

If DTC P0740 is output again after the MFI-DTC has been erased, replace the PCM.

Then check that the DTC is not output.