Test TC-148A - Torque Converter Clutch, No Rpm Drop At Lockup DTC 37/P0740)

CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.

NOTE: For connector terminal identification, you should see CONNECTOR IDENTIFICATION . For appropriate wiring diagram, see WIRING DIAGRAMS . You should perform the VERIFICATION TEST VER-1A after each repair.

NOTE: For engine-related DTC's, see appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. These DTC's pertain to engine performance and must be repaired first, as engine performance and related component signals will affect transmission operation and diagnosis.

Using scan tool, read DTCs. If any DTC listed in the TORQUE CONVERTOR CLUTCH (TCC) TESTS TABLE table is present, perform appropriate test(s). If no DTCs are present, go to next step.

TORQUE CONVERTOR CLUTCH (TCC) TESTS

DTC Message

Test

Throttle Position Sensor Voltage Too Low

TC-26A⁽¹⁾

Throttle Position Sensor Voltage Too High

TC-27A⁽¹⁾

PCM Failure EEPROM Write Denied

TC-49A⁽¹⁾

Torque Convertor Clutch Solenoid

TC-12A⁽¹⁾

Speed Control System ⁽²⁾

TC-35A⁽¹⁾

No Crank Reference Signal At PCM

TC-40A⁽¹⁾

⁽¹⁾	These engine performance-related tests are found in the appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.

⁽²⁾	Any vehicle speed sensor signal DTC.

Check transmission fluid for proper level and for any debris. Fill or repair transmission as necessary. If fluid level and condition are okay, go to next step.
Remove Vehicle Speed Sensor (VSS) and check for correct gear. Replace gear if necessary. If gear is okay, go to next step.
Reinstall VSS. Connect a 0-300 psi pressure gauge to transmission cooler output line. With an assistant, test drive vehicle. Ensure engine and transmission are at operating temperature. Note transmission pressure before lock-up. Go to next step.
Using scan tool, monitor TCC solenoid state. If transmission pressure does not increase when scan tool displays ENERGIZED (lock-up achieved), repair TCC solenoid and related components as necessary,. If pressure increases, no problem is found at this time. Test is complete.