Circuit Description
The transmission control module (TCM) provides voltage to the torque converter clutch pulse width modulated (TCC PWM) solenoid valve through high side driver 2 (HSD2). The TCM controls the ON and OFF time of the solenoid by providing a ground through the output driver module (ODM) . The TCM uses a PWM 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 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
| • | Ignition voltage is between 8-18 volts. |
| • | The engine speed is between 450-6,800 RPM for 5 seconds. |
| • | HSD2 is commanded ON. |
Conditions for Setting the DTC
DTC P2764 sets when either of the following conditions occur more than 43 out of 50 samples:
| • | The TCM detects an open in the TCC PWM solenoid valve circuit when the PWM duty cycle is greater than 20 percent. |
| • | The TCM detects a short to ground in the TCC PWM solenoid valve circuit when the PWM duty cycle is greater than 20 percent but less than 50 percent. |
Action Taken When the DTC Sets
| • | The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met. |
| • | The TCM turns off power to all solenoids. |
| • | The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear. |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame. |
| • | The TCM stores DTC P2764 in TCM history. |
Conditions for Clearing the DTC
| • | The ECM turns OFF the MIL after the sixth consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the MIL/clearing 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 default actions when the ignition is OFF long enough in order to power down the TCM. |
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:
Does the solenoid operate? | -- | Go to Step 9 | Go to Step 3 | |||||
3 |
Does the test lamp illuminate? | -- | Go to Step 4 | Go to Step 7 | ||||
4 |
Refer to Component Resistance . Is the resistance within the specified range? | 10.0-13.6Ω | Go to Step 5 | Go to Step 8 | ||||
5 | Using the DMM, measure the resistance for J 45681 terminal 17 to ground. Is the resistance greater than the specified value? | 50K Ω | Go to Step 6 | Go to Step 8 | ||||
6 |
Refer to Testing for Continuity and Testing for Short to Ground . Did you find the condition? | -- | Go to Step 10 | Go to Step 9 | ||||
7 |
Did you find the condition? | -- | Go to Step 10 | Go to Step 9 | ||||
8 |
Refer to Testing for Continuity and Testing for Short to Ground . Did you find the condition? | -- | Go to Step 11 | Go to Step 12 | ||||
9 | Replace the TCM. Refer to Control Module References . Is the operation complete? | -- | Go to Step 13 | -- | ||||
10 | Perform the necessary wiring repairs. Refer to Circuit Testing and Wiring Repairs . Is the operation complete? | -- | Go to Step 13 | -- | ||||
11 | Replace the AT internal transmission wiring harness. Refer to Transmission Internal Electrical Harness Replacement . Is the operation complete? | -- | Go to Step 13 | -- | ||||
12 | Replace the TCC PWM solenoid valve. Refer to Torque Converter Clutch Solenoid Replacement . Is the operation complete? | -- | Go to Step 13 | -- | ||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 14 | Go to Step 2 | ||||
14 | 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 |
