Circuit Description
Ignition voltage is provided to the torque converter clutch pulse width modulated (TCC PWM) solenoid valve. The TCM controls the solenoid with a negative duty cycle in order to control application and release of the TCC. When the solenoid is commanded OFF, the TCM senses high voltage. When the solenoid is commanded ON, the TCM senses low voltage.
When the TCM detects an open or short to ground in the TCC PWM solenoid valve 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 engine speed is greater than 500 RPM for 5 seconds.
Conditions for Setting the DTC
The TCM detects an open or short to ground on the TCC PWM solenoid valve control circuit for 4.4 seconds.
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 forces TCC OFF. |
| • | The TCM inhibits TCC engagement. |
| • | The TCM inhibits 4th gear if the transmission is in Hot Mode. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Freeze Frame and Failure Records. |
| • | The TCM stores DTC P2764 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met. |
Conditions for Clearing the MIL/DTC
| • | The ECM turns OFF the MIL after the third consecutive trip in which the TCM does not send an MIL illumination request. |
| • | A scan tool can clear the MIL/DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM. |
Diagnostic Aids
Ensure the wiring harness is not stretched too tightly or other components are pressing on the A/T inline 20-way connector body. Also inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. Using the Clear Info function will erase the stored Freeze Frame and Failure Records from the TCM. Are DTCs P0973 or P0976 also set? | -- | Go to Step 3 | Go to Step 9 | |
3 |
Was the fuse open? | -- | Go to Step 4 | Go to Step 7 |
4 |
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 1 voltage 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 Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 5 |
5 |
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. Did you find the condition? | -- | Go to Step 17 | Go to Step 6 |
6 |
Did you complete the replacement? | -- | Go to Step 20 | -- |
7 | Test the ignition 1 voltage circuit of the TCC PWM solenoid valve for an open between the fuse block and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 8 |
8 | Test the ignition 1 voltage circuit of the TCC PWM solenoid valve for an open between the AT inline 20-way connector and the solenoid. Refer to Testing for Continuity . Did you find and correct the condition? | -- | Go to Step 17 | Go to Testing for Intermittent Conditions and Poor Connections |
9 |
Refer to Automatic Transmission Inline 20-Way Connector End View . Does the test lamp turn ON and OFF? | -- | Go to Step 12 | Go to Step 10 |
10 | Test the ignition 1 voltage circuit of the TCC PWM solenoid valve for an open between the fuse block and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 11 |
11 | Test the control circuit of the TCC PWM solenoid valve for an open, a short to ground or a short to voltage 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 |
12 |
Does the resistance measure within the specified range? | 10-15 ohms | Go to Step 13 | Go to Step 16 |
13 | Measure the resistance from both sides of the TCC PWM solenoid valve to the transmission case. Are both readings greater than the specified value? | 250K ohms | Go to Step 14 | Go to Step 15 |
14 | Measure the resistance from the control side of the TCC PWM solenoid valve and all other terminals of the A/T inline 20-way connector. Refer to Testing for Continuity . Is the resistance less than the specified value? | 250K ohms | Go to Step 16 | Go to Testing for Intermittent Conditions and Poor Connections |
15 |
Are both readings greater than the specified value? | 250K ohms | Go to Step 17 | Go to Step 18 |
16 |
Is the resistance within the specified range? | 10-15 ohms | Go to Step 17 | Go to Step 18 |
17 | Replace the automatic transmission wiring harness assembly. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | Go to Step 20 | -- |
18 | Replace the TCC PWM solenoid valve. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid Replacement . 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 a 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 |
