P0740–TCC OUT OF RANGE

For a complete wiring diagram Refer to Section 8W

When Monitored:
During Electronically Modulated Converter Clutch (EMCC) Operation.
Set Condition:
Transmission must be in EMCC, with input speed greater than 1750 RPM. TCC/LR Solenoid achieves the maximum duty cycle and can not pull engine speed within 60 RPM of input speed. Also when the transmission is in FEMCC and the engine slips TCC less than 100 RPM for 10 seconds. This DTC can take up to five minutes of problem identification before illuminating the MIL.

Possible Causes

RELATED DTC P0750 PRESENT

L/R SOLENOID

TCC SWITCH VALVE STUCK

TCC REGULATOR VALVE STUCK

INPUT SHAFT SEAL RING CUT

TORQUE CONVERTER

Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

Theory of Operation

When in 2nd, 2nd Prime, 3rd, 4th, or 5th gear, the torque converter clutch (TCC) can be engaged when certain conditions are met. The TCC piston is electronically modulated by increasing the duty cycle of the LR Solenoid until the torque converter slip difference (difference between engine and transmission input speed) is within 60 RPM. Then the LR solenoid is fully energized (FEMCC – 100% duty cycle). Torque converter slip is monitored in FEMCC to ensure adequate clutch capacity.

Diagnostic Test

1.DETERMINING IF RELATED DTC P0750 IS PRESENT

Is the DTC P0750 present also?

Yes

Refer to the Transmission category and perform the appropriate symptom.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

Go To 2

2.CHECK TO SEE IF DTC P0740 IS CURRENT

NOTE: If the throttle angle goes over 30 degrees, you must close the throttle and try again.

Did the TCC engage during any of the attempts, Engine speed approximately equal to input speed?

Yes

Go To 3

Go To 4

3.INTERMITTENT WIRING AND CONNECTORS

Were there any problems found?

Yes

Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

Test Complete.

4.LR SOLENOID

Are the DTCs P1775 and P0841 present also?

Yes

Replace the Transmission Solenoid/TRS Assembly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

Go To 5

5.TORQUE CONVERTER AND/OR INTERNAL TRANSMISSION

View repair.

Repair

In all cases, replace the Torque Converter. Make sure to check all other possible causes in addition to the Torque Converter.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)