DTC P0740 sets if one of the following conditions occurs for 5 seconds:
Condition 1The PCM commands the solenoid ON and the voltage feedback remains high (B+).
Condition 2The PCM commands the solenoid OFF and the voltage feedback remains low (0 volt).
With the TCC engaged, the TCC slip speed should be -20 to +40 RPM.
The numbers below refer to the step numbers on the diagnostic table.
This step tests the ability of the PCM and wiring to control the ground circuit.
This step tests the resistance of the TCC solenoid valve and the automatic transmission (AT) wiring harness assembly.
|
Step |
Action |
Value(s) |
Yes |
No |
|---|---|---|---|---|
|
1 |
Did you perform the Powertrain Diagnostic System Check? |
-- |
Go to Diagnostic System Check - Engine Controls in Engine Controls - 5.7 L |
|
|
2 |
Are any of the following DTCs also set?
|
-- |
||
|
3 |
Inspect the ENG CTRL fuse for an open. Refer to General Electrical Diagnosis Procedures in Wiring Systems. Is the fuse open? |
-- |
||
Does the test lamp illuminate? |
-- |
|||
Does the test lamp turn ON and OFF with each command? |
-- |
|||
|
6 |
Is the test lamp always ON? |
-- |
||
Does the resistance measure within the specified range? |
21-33 ohms |
|||
|
8 |
Do both readings measure greater than the specified value? |
250 K ohms |
Go to Intermittent Conditions in Engine Controls - 5.7 L |
|
|
9 |
The condition that affects this circuit may exist in other connecting
branches of the circuit. Refer to Power
Distribution Schematics in Wiring Systems for complete circuit
distribution. Test the ignition 1 voltage circuit (CKT 239) of the TCC solenoid valve for a short to ground between the engine wiring harness junction block 2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? |
-- |
||
|
10 |
The condition that affects this circuit may exist in other connecting
branches of the circuit. Refer to Power
Distribution Schematics in Wiring Systems for complete circuit
distribution. Test the ignition 1 voltage circuit (CKT 839) of the TCC solenoid valve for a short to ground between the AT inline 20-way connector and the TCC solenoid valve. Refer to Circuit Testing in Wiring Systems. Did you find a short to ground condition? |
-- |
||
|
11 |
Did you complete the replacement? |
-- |
-- |
|
|
12 |
The condition that affects this circuit may exist in other connecting
branches of the circuit. Refer to Power
Distribution Schematics in Wiring Systems for complete circuit
distribution. Test the ignition 1 voltage circuit (CKT 239) of the TCC solenoid valve for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? |
-- |
-- |
|
|
13 |
Test the control circuit (CKT 422) of the TCC solenoid valve for a short to ground between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? |
-- |
||
|
14 |
Test the control circuit (CKT 422) of the TCC solenoid valve for an open or short to power between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? |
-- |
||
|
15 |
Replace the AT wiring harness assembly (this includes the TCC solenoid valve). Refer to Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid, TCC Solenoid, and Wiring Harness . Did you complete the replacement? |
-- |
-- |
|
|
16 |
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 5.7 L. Did you complete the replacement? |
-- |
-- |
|
|
17 |
Perform the following procedure in order to verify the repair:
Has the test run and passed? |
-- |
System OK |