DTC P2764 3.9L
Circuit Description
The torque converter clutch pulse width modulated (TCC PWM) solenoid valve is a normally closed solenoid used to control the apply and release of the converter clutch. The transmission control module (TCM) operates the solenoid with a negative duty cycle. When vehicle operating conditions are appropriate to apply the TCC, the TCM immediately increases the duty cycle to approximately 42 percent. The TCM then ramps the duty cycle to approximately 90 percent to achieve full TCC apply pressure. 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 a continuous 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 is running for 5 seconds or more.
Conditions for Setting the DTC
The TCM detects an open or short to ground on the TCC PWM solenoid valve circuit for 4.4 seconds.
Action Taken When the DTC Sets
| • | The TCM illuminates 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 the TCC solenoid OFF. |
| • | The TCM inhibits TCC engagement. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM inhibits 4th gear in Hot Mode. |
| • | 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. |
Conditions for Clearing the MIL/DTC
| • | The TCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | 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 numbers below refer to the step numbers on the diagnostic table.
-
This step tests the electrical operation of the solenoid.
-
This step verifies the TCMs ability to command the solenoid.
-
This step verifies that the circuit has the correct resistance.
Step | Action | Value(s) | 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 TCM. Is DTC P0973 or P0976 also set? | -- | Go to Step 3 | Go to Step 8 | ||||
3 |
Refer to Circuit Protection - Fuses . Did you find the condition? | -- | Go to Step 4 | Go to Step 6 | ||||
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 underhood 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 22 | 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. Test the ignition 1 voltage 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 the condition? | -- | Go to Step 19 | -- | ||||
6 | Test the ignition 1 voltage circuit of the TCC PWM solenoid valve for an open between the underhood 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 22 | Go to Step 7 | ||||
7 | Test the ignition 1 voltage circuit of the TCC PWM solenoid valve for an open between the AT inline 20-way connector and the TCC PWM solenoid valve. Refer to Testing for Continuity . Did you find the condition? | -- | Go to Step 19 | -- | ||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Is the test lamp ON when you command the solenoid ON, and OFF when you command the solenoid OFF? | -- | Go to Step 13 | Go to Step 9 | |||||
Is the test lamp always ON? | -- | Go to Step 10 | Go to Step 12 | |||||
10 |
Is the test lamp ON? | -- | Go to Step 11 | Go to Step 21 | ||||
11 | Test the control circuit of the TCC PWM solenoid valve for a short to ground between the TCM connector 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 22 | -- | ||||
12 | Test the control circuit of the TCC PWM solenoid valve for an open between the TCM connector 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 22 | Go to Step 21 | ||||
13 |
Refer to Automatic Transmission Inline 20-Way Connector End View . Is the resistance within the specified range? | 10-15 ohms | Go to Step 16 | Go to Step 14 | ||||
Is the resistance greater than the specified value? | 15 ohms | Go to Step 15 | Go to Step 16 | |||||
15 |
Refer to Testing for Continuity . Did you find a condition? | -- | Go to Step 19 | Go to Step 20 | ||||
16 | Measure the resistance from the TCC PWM solenoid valve control circuit of the J 44152 to ground. Refer to Automatic Transmission Inline 20-Way Connector End View . Is the resistance less than the specified value? | 100 ohms | Go to Step 17 | Go to Step 18 | ||||
17 | Test the control 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 the condition? | -- | Go to Step 19 | -- | ||||
18 | Measure the resistance between the TCC PWM solenoid valve control circuit and all other terminals, except the ignition 1 voltage, the 1-2 SS valve control and the 2-3 SS valve control circuits, of the J 44152 . Refer to Automatic Transmission Inline 20-Way Connector End View . Is the resistance less than the specified value? | 100 ohms | Go to Step 19 | Go to Step 20 | ||||
19 | Replace the automatic transmission wiring harness assembly. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- | ||||
20 | Replace the TCC PWM solenoid valve. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- | ||||
21 | Replace the TCM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | -- | Go to Step 22 | -- | ||||
22 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | Go to Step 23 | Go to Step 2 | |||||
23 | 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 |
