The transmission control module detects an internal low voltage electrical malfunction of the clutch pressure control solenoid 4 control circuit for
500 milliseconds.
P2721
The transmission control module detects an internal high voltage electrical malfunction of the clutch pressure control solenoid 4 control circuit for
500 milliseconds.
Action Taken When the DTC Sets
* P2719 is a Type B DTC.
* P2720 and P2721 are Type A DTCs.
* The transmission control module defaults the transmission to a limited shift pattern utilizing 2 forward gears and reverse based on the default
detected.
* The transmission control module commands maximum line pressure.
* The transmission control module freezes transmission adaptive functions.
Conditions for Clearing the DTC
* P2719 is a Type B DTC.
* P2720 and P2721 are Type A DTCs.
Diagnostic Aids
When attempting to set solenoid electrical DTCs, ensure the transmission control module is warmed up and the transmission is operated long
enough to ensure a 3锟斤拷C (5锟斤拷F) increase in TCM temperature. This will place the transmission control module under the optimal conditions to test
solenoid electrical DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Circuit/System Verification
1. Engine ON, verify the transmission fluid temperature is between 50-80锟斤拷C (122-176锟斤拷F).
2. Operate the vehicle long enough to verify at least a 3锟斤拷C (5锟斤拷F) rise in the TCM temperature parameter, then operate the vehicle in Park for 5
seconds.
3. Engine ON, observe the scan tool Clutch PC 4 Sol. CKT Status parameter. The reading should display OK or Indeterminate.
锟斤拷If the reading is not within the specified range, replace the Q8 control solenoid valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for Q8 control solenoid valve assembly replacement,
setup, and programming.
6L50/6L80/6L90 - Automatic Transmission
