6T70/6T75 - Automatic Transmission
DTC P0961, P0962 or P0963
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 P0961
- Line Pressure Control (PC) Solenoid System Performance
DTC P0962
- Line Pressure Control (PC) Solenoid Control Circuit Low Voltage
DTC P0963
- Line Pressure Control (PC) Solenoid Control Circuit High Voltage
Circuit/System Description
The line pressure control (PC) solenoid is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The line PC solenoid regulates the transmission fluid line pressure. The TCM varies the current to the normally high line PC solenoid valve from 0.1 amp for maximum line pressure, to 1.1 amps for minimum line pressure.
Conditions for Running the DTC
* The engine speed is greater than 500 RPM for 5 seconds.
* The ignition voltage is between 8.6 volts and 19.0 volts.
* The line PC solenoid is commanded ON.
Conditions for Setting the DTC
P0961
The TCM detects an invalid voltage in the line PC solenoid control circuit for 4.4 seconds in a 5.0 second sample.
P0962
The TCM detects low voltage on the line PC solenoid control circuit for 300 milliseconds in a 375 millisecond sample.
P0963
The TCM detects high voltage on the line PC solenoid control circuit for 300 milliseconds in a 375 millisecond sample.
Action Taken When the DTC Sets
P0961
* DTC P0961 is a Type C DTC.
* The TCM freezes transmission adaptive functions.
P0962
* DTC P0962 is a Type A DTC.
* The TCM defaults the transmission to 3rd gear if the current gear is 1st, 2nd, or 3rd, or 5th gear if the current gear if 4th, 5th, or 6th gear.
* The TCM inhibits the torque converter clutch (TCC).
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
P0963
* DTC P0963 is a Type C DTC.
* The TCM freezes transmission adaptive functions.
* The TCM commands maximum line pressure.
Conditions for Clearing the DIC/DTC
* DTCs P0961 and P0963 are Type C DTCs.
* DTC P0962 is a Type A DTC.
Reference Information
Description and Operation
Transmission General Description (Transmission General 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) to dislodge debris and free up the valves.
3. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature, then operate the vehicle in Park for 5 seconds.
4. Verify the scan tool Line PC Sol. CKT Status parameter displays OK.
• If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Important: Perform the Service Fast Learn Adapts (Programming and Relearning) following all transmission related repairs.
* Control Solenoid Valve and Transmission Control Module Assembly Cleaning (Control Solenoid Valve and Transmission Control Module Assembly Cleaning)
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)
* Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.