The powertrain control module (PCM) uses signals from the throttle position (TP) sensor, mass air flow (MAF) and the crankshaft position (CKP) sensor to monitor the engagement of the torque converter clutch (TCC) lock-up status. The PCM then compares the actual data with the TCC lock-up schedule in the PCM memory to detect mechanical trouble of the TCC solenoid, valve body or automatic transaxle.
This diagnostic procedure supports the following DTC:
DTC P0741 Torque Converter Clutch (TCC) System-Stuck Off
DTC P0741 will set when one of the following conditions are met:
• | TCC lock-up does not occur after the PCM commands the TCC to apply. |
• | TCC remains locked-up even after the PCM commands the TCC to release. |
A DTC P0741 is stored and the malfunction indicator lamp (MIL) is turned ON.
Inspect for the following conditions:
• | Clogged or leaky TCC solenoid |
• | Valve body fluid passage clogged |
• | Torque converter clutch malfunction |
• | Faulty PCM |
If this DTC cannot be duplicated, the information included in the freeze frame data can be useful in determining vehicle operating conditions when the DTC was first set.
The numbers below refer to the step numbers on the diagnostic table.
The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
This step checks for proper shift points.
This step checks for a stuck closed lock-up solenoid.
This step checks for a leaky lock-up solenoid.
This step checks the condition of the valve body assembly.
This step checks for a faulty PCM.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | |||
Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | ||
2 | Does the scan tool display any other DTCs? | Go to applicable DTC table | Go to Step 3 |
3 |
Did DTC P0741 reset? | Go to Step 4 | Go to Diagnostic Aids |
Perform the Upshifts and Torque Converter Clutch Apply Procedure in Road Test in order to diagnose the mechanical condition of the transaxle. Was a mechanical failure detected? | Go to Step 11 | Go to Step 5 | |
Did the lock-up solenoid outlet port open and did air escape? | Go to Step 10 | Go to Step 6 | |
Did the lock-up solenoid outlet port stay closed and did no air leak? | Go to Step 10 | Go to Step 7 | |
Remove valve body and inspect its passages for any obstructions/restrictions. Refer to Solenoids and Wiring Harness Replacement . Is the valve body in good condition? | Go to Step 8 | Go to Step 9 | |
Does this DTC reset? | Go to Step 11 | Go to Step 12 | |
9 | Repair or overhaul valve body assembly. Is the action complete? | Go to Step 13 | -- |
10 | Replace the lock-up solenoid. Is the action complete? | Go to Step 13 | -- |
11 | Refer to Road Test for further diagnosis of the transaxle performance. Repair as necessary. Is the action complete? | Go to Step 13 | -- |
12 | Replace the PCM. Refer to Powertrain Control Module Programming and Setup. Is the action complete? | Go to Step 13 | -- |
13 | Perform the DTC Confirmation Procedure. Are any DTCs displayed on the Scan Tool? | System OK |