2010 Cadillac CTS Sedan AWD V6-3.6L Page 1720
Conditions for Clearing the DTC
DTCs P0877 and P0878 are Type C DTCs.
Diagnostic Aids
A TFP switch may malfunction due to normal debris in the transmission fluid causing a TFP Switch DTC to intermittently set. This type of
condition should not be immediately noticeable to a customer, as the switch outputs are used for shift adaptive pressure and do not cause
transmission symptoms unless the switch malfunctions continuously for an extended period of time.
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)
* Inline Harness Connector End Views (See: Power and Ground Distribution/Multiple Junction Connector/Diagrams)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Description and Operation
* Electronic Component Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Electronic Component Description)
* Transmission General Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Transmission General Description)
* Transmission Component and System Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Transmission Component and System Description)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Special Tools
DT-47825-10 - Jumper Harness
Circuit/System Verification
1. Engine idling in Park with parking brake applied, and drive wheels chocked.
2. Monitor the Transmission Fluid Pressure Switch 1, Transmission Fluid Pressure Switch 3, Transmission Fluid Pressure Switch 4, and
Transmission Fluid Pressure Switch 5 parameters with a scan tool.
3. Place the gear select lever in Park, Reverse, and Neutral range. Verify the TFP switch parameter states are correct for each range. Refer to
Transmission Fluid Pressure Switch Logic (See: Specifications/Mechanical Specifications/Automatic Transmission/Transaxle/System
Specifications/Transmission Fluid Pressure Switch Logic).
4. Place the gear select lever in Drive range. Command the shift transmission with a scan tool through all forward ranges. Verify the TFP switch
parameter states are correct for each range. Refer to Transmission Fluid Pressure Switch Logic (See: Specifications/Mechanical
Specifications/Automatic Transmission/Transaxle/System Specifications/Transmission Fluid Pressure Switch Logic).
5. Operate the vehicle within the conditions for running the DTC to verify the TDC 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 Valve Body Assembly Removal (See: Transmission and
Drivetrain/Automatic Transmission/Transaxle/Service and Repair/Overhaul/6L45 Transmission/5. Control Valve Body Assembly Removal).
2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (See: Transmission and Drivetrain/Automatic
Transmission/Transaxle/Testing and Inspection/Component Tests and General Diagnostics/Control Solenoid Valve and Transmission Control
