6L50/6L80/6L90 - Automatic Transmission
DTC P2728-P2730
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) 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
Typical Scan Tool Data
Circuit/System Description
The clutch pressure control (PC) solenoid 5 is part of the control solenoid valve assembly which has no serviceable parts. The normally low PC solenoid 5 regulates and directs oil pressure to the 1-2-3-4 clutch regulator valve and 1-2-3-4 clutch boost valve. Increasing PC solenoid 5 pressure increases pressure to the 1-2-3-4 clutch. The TCM varies the current to the PC solenoid 5 through a low side driver. Increasing the current to PC solenoid 5 increases oil pressure by closing OFF the solenoid exhaust port. Decreasing the current to PC solenoid 5 decreases oil pressure by opening the exhaust port. PC solenoid 5 power is supplied by the TCM through a high side driver (HSD). The HSD protects the circuit and components from excessive current flow. If excessive current flow is detected, the HSD will turn OFF. When the fault is corrected, the HSD will reset.
Conditions for Running the DTC
P2728, P2729, or P2730
* DTCs P2728, P2729, or P2730 have not set this ignition.
* The ignition voltage is 8.6 volts or greater.
* The engine speed is 400 RPM or greater for 5 seconds.
* The clutch PC solenoid 5 is commanded ON.
Conditions for Setting the DTC
P2728
The TCM detects an internal electrical performance malfunction of the clutch PC solenoid 5 control circuit where the measured clutch PC solenoid 5 current does not equal the commanded clutch PC solenoid 5 current for 5 seconds.
P2729
The TCM detects a short to ground on the clutch PC solenoid 5 control circuit for 1 second.
P2730
The TCM detects an open or short to voltage on the clutch PC solenoid 5 control circuit for 1 second.
Action Taken When the DTC Sets
P2728
* DTC P2728 is a Type C DTC.
* The TCM freezes transmission adaptive functions.
P2729
* DTC P2729 is a Type A DTC.
* The transmission defaults to 2nd gear or reverse gear.
* The TCM forces TCC OFF.
* The TCM freezes transmission adaptive functions.
* The TCM commands maximum line pressure.
* The TCM enables Torque management.
* The TCM inhibits TAP Up/Down function.
P2730
* DTC P2730 is a Type A DTC.
* The transmission defaults to 5th gear or reverse gear.
* The TCM forces TCC OFF.
* The TCM freezes transmission adaptive functions.
* The TCM commands maximum line pressure.
* The TCM enables Torque management.
* The TCM inhibits TAP Up/Down function.
* The TCM turns OFF the high side driver.
Conditions for Clearing the DTC
* DTC P2728 is a Type C DTC.
* DTCs P2729 and P2730 are Type A DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Diagrams)
Connector End View Reference
* Component Connector End Views (Connector Views)
* Inline Harness Connector End Views (Diagrams)
Description and Operation
* Transmission General Description ()
* Transmission Component and System Description ()
* Electronic Component Description ()
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
DT-47825-10 - Jumper Harness
Circuit/System Verification
1. Operate the vehicle in second gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature.
2. Operate the vehicle in drive range. Allow the transmission to shift through all forward gear ranges. Verify with a scan tool the following test status parameters display OK:
* Pressure Control Solenoid Valve 5 Performance Test Status
* Pressure Control Solenoid Valve 5 Control Circuit High Voltage Test Status
* Pressure Control Solenoid Valve 5 Control Circuit Low Voltage Test Status
3. 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.
Circuit/System Testing
Note: You must perform the Circuit/System Verification first.
1. Ignition OFF, remove the Q8 control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement ().
2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection ().
3. Place the Q8 control solenoid valve assembly on a clean work surface near the transmission assembly.
4. Connect DT-47825-10 - jumper harness between the vehicle wire harness electrical connector, and the Q8 control solenoid valve assembly electrical connector.
5. Ignition ON, verify with a scan tool the following test status parameters display OK:
* Pressure Control Solenoid Valve 5 Performance Test Status
* Pressure Control Solenoid Valve 5 Control Circuit High Voltage Test Status
* Pressure Control Solenoid Valve 5 Control Circuit Low Voltage Test Status
• If any test status parameter displays Fault or Malfunction, replace the Q8 control solenoid valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Perform the Service Fast Learn Adapts () following all transmission related repairs.
* Replace the control solenoid valve assembly. Refer to Control Module References (Programming and Relearning) for replacement, setup, and programming.