2010 Cadillac CTS Sedan AWD V6-3.6L Page 1697
The TCM detects a Stuck ON downshift switch for 3 seconds in PARK, REVERSE, NEUTRAL, or D and for 600 seconds in PARK, REVERSE,
NEUTRAL, or D.
P0826
The TCM detects an invalid voltage on the TAP Up/Down Signal Circuit for 8 seconds.
P1876
The TCM detects a TAP Enable Switch request 3 times when not in D6 range for 2 seconds.
Action Taken When the DTC Sets
* DTCs P0815, P0816, P0826, and P1876 are Type C DTCs.
* The TCM disables TAP shift functions.
Conditions for Clearing the DTC
DTCs P0815, P0816, P0826, and P1876 are Type C 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)
* 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)
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
Circuit/System Verification
1. Engine running, park brake applied, drive wheels chocked. Shift the transmission into the manual (M) position. Verify with a scan tool the
following TCM parameters display the correct values:
* Drivers Shift Control - Inactive
* Drivers Shift Request - None
2. Verify with a scan tool the following TCM parameters display the correct values when pushing the shift lever forward or pressing the plus
button:
* Drivers Shift Control - Active
* Drivers Shift Request - Upshift
3. Verify with a scan tool the following TCM parameters display the correct values when pushing the shift lever rearward or pressing the minus
button:
* Drivers Shift Control - Active
* Drivers Shift Request - Downshift
4. 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
