Circuit Description
The torque converter clutch pulse width modulation (TCC PWM) solenoid valve controls the fluid acting on the converter clutch valve. The converter clutch valve controls the TCC application and release. The solenoid attaches to the control valve body within the transmission. The solenoid receives voltage through the ignition voltage circuit. The transmission control module (TCM) controls the solenoid by providing a ground path on the TCC PWM solenoid valve control circuit. Current flows through the solenoid coil according to the duty cycle, percentage of ON and OFF time. The TCC PWM solenoid valve provides a smooth engagement of the TCC by operating during a duty cycle percent of ON time.
When the TCM detects a continuous open or short to ground in the TCC PWM solenoid valve control circuit, then DTC P2764 sets. DTC P2764 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2764 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit Low Voltage
Conditions for Running the DTC
| • | The system voltage is 8-18 volts. |
| • | The engine speed is 475 RPM for 5 seconds. |
Conditions for Setting the DTC
DTC P2764 sets when either of the following conditions occurs for 5 seconds:
| • | The TCM detects an open in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded ON. |
| • | The TCM detects a short to ground in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded ON. |
Action Taken When the DTC Sets
| • | The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | The TCM commands maximum line pressure. |
| • | The TCM inhibits TCC engagement. |
| • | The TCM inhibits 4th gear if in hot mode. |
| • | The TCM freezes transmission adaptive functions. |
| • | The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records. |
| • | The TCM stores DTC P2764 in TCM history. |
Conditions for Clearing the DTC
| • | The ECM turns OFF the MIL after the 4th consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for voltage to the solenoid.
-
This step tests the ability of the TCM and wiring to control the ground circuit.
-
This step tests the resistance of the TCC PWM solenoid valve and the automatic transmission (AT) wiring harness.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the transmission control module (TCM). Are any of the following DTCs also set?
| -- | Go to Step 3 | Go to Step 4 | ||||||||
3 | Inspect the ignition voltage supply fuse for an open. Refer to Circuit Protection - Fuses . Is the fuse open? | -- | Go to Step 11 | Go to Step 4 | ||||||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 14 | |||||||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Does the test lamp turn ON and OFF with each command? | -- | Go to Step 7 | Go to Step 6 | |||||||||
6 | Is the test lamp always ON? | -- | Go to Step 15 | Go to Step 16 | ||||||||
Refer to Testing for Continuity . Refer to Automatic Transmission Inline 20-Way Connector End View . Does the resistance measure within the specified range? | 10-15 ohms | Go to Step 8 | Go to Step 9 | |||||||||
8 | Measure the resistance from the TCC PWM solenoid valve ignition voltage and control circuits to ground. Refer to Testing for Continuity . Do both readings measure greater than the specified value? | 250 K ohms | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 10 | ||||||||
9 |
Refer to Testing for Continuity . Does the resistance measure within the specified range? | 10-15 ohms | Go to Step 17 | Go to Step 18 | ||||||||
10 |
Refer to Testing for Continuity . Do both readings measure greater than the specified value? | 250 K ohms | Go to Step 17 | Go to Step 18 | ||||||||
11 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution. Test the ignition circuit of the TCC PWM solenoid valve for a short to ground between the fuse block and the AT inline 20-way connector. Refer to Testing for Short to Ground and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 12 | ||||||||
12 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution. Test the ignition circuit of the TCC PWM solenoid valve for a short to ground between the AT inline 20-way connector and the TCC PWM solenoid valve. Refer to Testing for Short to Ground . Did you find a short to ground condition? | -- | Go to Step 17 | Go to Step 13 | ||||||||
13 |
Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||
14 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution. Test the ignition circuit of the TCC PWM solenoid valve for an open. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | -- | ||||||||
15 | Test the control circuit of the TCC PWM solenoid valve for a short to ground between the TCM and the AT inline 20-way connector. Refer to Testing for Short to Ground and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19 | ||||||||
16 | Test the control circuit of the TCC PWM solenoid valve for an open between the TCM and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19 | ||||||||
17 | Replace the AT wiring harness. Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||
18 | Replace the TCC PWM solenoid valve. Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||
19 | Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||||
20 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 21 | Go to Step 2 | ||||||||
21 | With the scan tool, observe the stored information, capture info, and DTC Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
