2010 Cadillac CTS Sedan AWD V6-3.0L Page 1692

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1692

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 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

Module Assembly Inspection).

3. Place the Q8 control solenoid valve assembly on a clean work surface near the transmission assembly.

4. Connect the 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 that each TFP switch parameter changes states when gently pushing on each TFP switch with the eraser

end of a pencil.

瀚慖f any TFP switch parameter does not change states, replace the Q8 control solenoid valve assembly.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Control solenoid valve assembly replacement. Refer to Control Module References (See: Testing and Inspection/Programming and

Relearning) for replacement, setup, and programming.

* Perform the Service Fast Learn Adapts (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and

Inspection/Programming and Relearning/Service Fast Learn Adapts) following all transmission related repairs.

P0877

DTC P0877 or P0878

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0877

- Transmission Fluid Pressure (TFP) Switch 4 Circuit Low Voltage

DTC P0878

- Transmission Fluid Pressure (TFP) Switch 4 Circuit High Voltage

Diagnostic Fault Information

Typical Scan Tool Data