Circuit Description
The ignition voltage is provided to the torque converter clutch pulse width modulated (TCC PWM) solenoid valve. The powertrain control module (PCM) controls the ON and OFF time of the TCC PWM solenoid by controlling the ground side of the TCC solenoid valve control circuit. The PCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the PCM senses high voltage. When the solenoid is commanded ON, the PCM senses low voltage.
When the PCM detects a short to voltage in the TCC Solenoid valve control circuit, then DTC P2763 sets. DTC P2763 is a type B DTC.
Conditions for Running the DTC
| • | The engine run time is greater than 5 seconds. |
| • | TCC PWM solenoid valve duty cycle is less than or equal to 0 percent. |
Conditions for Setting the DTC
DTC P2763 sets when the PCM detects a short to voltage in the TCC PWM solenoid valve circuit.
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | The PCM commands maximum line pressure. |
| • | The PCM inhibits fourth gear if the transmission is in Hot Mode. |
| • | The PCM freezes transmission adaptive function. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. |
| • | The PCM stores DTC P2763 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | A scan tool can clear the MIL/DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring. |
| • | The PCM cancels the default actions when the ignition is OFF long enough in order to power down the PCM. |
Test Description
The number below refers to the step number on the diagnostic table.
-
This step tests the PCM and the wiring to the transmission.
-
This step verifies that the circuit has the correct resistance.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 4.6L | ||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the PCM Freeze Frame and the Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the PCM. When TCC is commanded, does the scan tool display indicate a short to voltage? | -- | Go to Step 3 | Go to Intermittent Conditions in Engine Controls - 4.6L | ||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Is the test lamp ON? | -- | Go to Step 4 | Go to Step 5 | |||||
4 | Test the control circuit of the TCC PWM solenoid valve for a short to voltage between the PCM connector C3 and the AT inline 20-way connector. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 | ||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Does the resistance measure within the specified range? | 10-25 ohms | Go to Step 7 | Go to Step 6 | |||||
6 |
Does the resistance measure less than the specified value? | 250 K ohms | Go to Step 8 | Go to Step 9 | ||||
7 | Measure the resistance between terminal T and all other terminals, except terminal U, of the J 44152 . Refer to Automatic Transmission Inline 20-Way Connector End View . Is the resistance between terminal T and any other terminal, except terminal U, less than the specified value? | 250 K ohms | Go to Step 8 | Go to Intermittent Conditions in Engine Controls - 4.6L | ||||
8 |
Important: The automatic transmission wiring harness consists of 2 separate harnesses, the Automatic Transmission Wiring Harness Assembly, GM P/N 15320475, and the Automatic Transmission Wiring Extension Harness Assembly, GM P/N 15320478. In order to avoid the unnecessary replacement of parts, determine which harness contains the fault and replace only that harness. Replace the automatic transmission wiring harness. Refer to Input Speed Sensor and Wiring Harness Removal in the 4T80-E section of the Transmission Unit Repair Manual. Did you complete the replacement? | -- | Go to Step 11 | -- | ||||
9 | Replace the TCC PWM solenoid valve. Refer to Control Valve Upper Body Disassemble in the 4T80-E section of the Transmission Unit Repair Manual. Did you complete the replacement? | -- | Go to Step 11 | -- | ||||
10 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.6L. Did you complete the replacement? | -- | Go to Step 11 | -- | ||||
11 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 12 | Go to Step 2 | ||||
12 | 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? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 4.6L | System OK |
