Automatic Transmission - 6T40/6T45
DTC P2728-P2730
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P2728
- Clutch Pressure Control (PC) Solenoid 5 System Performance
DTC P2729
- Clutch Pressure Control (PC) Solenoid 5 Control Circuit Low Voltage
DTC P2730
- Clutch Pressure Control (PC) Solenoid 5 Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The clutch pressure control (PC) solenoid 5 is part of the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly has no serviceable parts. The TCM supplies 12 volts to the clutch PC solenoid 5 through the high side driver circuit. The TCM controls the clutch PC solenoid 5 through the clutch PC solenoid 5 control circuit. The normally low clutch PC solenoid 5 flows fluid to the 1-2-3-4 clutch when commanded ON and exhausts fluid when commanded OFF. This allows the clutch PC solenoid 5 to regulate the transmission fluid pressure to the 1-2-3-4 clutch.
Conditions for Running the DTC
* The engine run time is greater than 5 seconds.
* The ignition voltage is between 9.0 volts and 19.0 volts.
* The clutch PC solenoid 4 is commanded ON.
* The suspect code (P02728, P02729 or P02730) has not failed this ignition cycled 19.0 volts.
Conditions for Setting the DTC
P2728
The TCM detects an internal electrical performance malfunction of the clutch PC solenoid 5 control circuit where the actual 1-2-3-4 clutch pressure does not equal the commanded 1-2-3-4 clutch pressure for 10.5 seconds or greater.
P2729
The TCM detects an internal low voltage electrical malfunction of the clutch PC solenoid 5 control circuit for 300 milliseconds.
P2730
The TCM detects an internal high voltage electrical malfunction of the clutch PC solenoid 5 control circuit for 300 milliseconds.
Action Taken When the DTC Sets
P2728
* DTC P2728 is a Type C DTC.
* The TCM freezes transmission adaptive functions.
P2729 and P2730
* DTCs P2729 and P2730 are Type A DTCs.
* The TCM defaults the transmission to a limited shift pattern utilizing 2 forward gears and reverse based on the default detected.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
Conditions for Clearing the DTC
* DTC P2728 is a Type C DTC.
* DTCs P2729 and P2730 are Type A DTCs.
Reference Information
Description and Operation
* Transmission General Description (Transmission General Description)
* Transmission Component and System Description (Transmission Component and System Description)
* Electronic Component Description (Electronic Component Description)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning (Control Solenoid Valve and Transmission Control Module Assembly Cleaning) procedure to dislodge debris and free up valves.
3. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature.
4. Verify that the scan tool data parameter, Clutch PC 5 Sol. CKT Status, displays OK.
• If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Important: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).
* Refer to Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.
* Perform the Service Fast Learn Adapts (Programming and Relearning) following all transmission related repairs.
* Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning (Control Solenoid Valve and Transmission Control Module Assembly Cleaning) procedure.