2010 Cadillac CTS Sedan AWD V6-3.6L Page 1791
Conditions for Setting the DTC
* The ECM detects the TP sensor angle is less than 10 percent or greater than 40 percent when the throttle actuator control motor is
deactivated.
* The condition exists, then a 5 second delay for MIL On.
Action Taken When the DTC Sets
DTC P1551 is a type A DTC.
Conditions for Clearing the DTC
DTC P1551 is a type A DTC.
Diagnostic Aids
* The scan tool has the ability to operate the throttle actuator control system using Special Functions. This function operates the throttle
through the entire range in order to determine if the throttle body and system operate correctly.
* Inspect for a condition in which the throttle valve may have been held open.
* Inspect for conditions in which ice may have formed in the throttle bore.
* The throttle valve is spring loaded to a slightly open position. This is referred to as the rest position. The throttle valve should not be
completely closed, nor should it be open any greater than predetermined amount. The throttle valve should move open and to the closed
position without binding under the normal spring pressure. The throttle should NOT be free to move open or closed WITHOUT spring
pressure.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Engine Control Module Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Engine Control
Module Description)
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. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0121, P0122, P0123, P0221, P0222, P0223, P2100, P2101, or
P2119 is not set.
瀚慖f a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble
Code (DTC) List - Vehicle) for further diagnosis.
2. Start the engine. Observe the DTC information with a scan tool for 30 seconds. DTC P1551 should not set.
3. 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
Ignition OFF, disconnect the air intake duct at the throttle body and inspect for the following:
