2010 Cadillac CTS Sedan AWD V6-3.6L Page 1848
4. Connect a test lamp between the TAC motor control 2 circuit terminal A and B+. The test lamp should NOT illuminate.
瀚慖f the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the engine control module.
5. Test for greater than 3.5 V between TAC motor control 1 circuit terminal B and TAC motor control 2 circuit terminal A.
瀚慖f the voltage is less than the specified value, test the motor control 2 circuit for an open/high resistance. If the circuit tests normal,
replace the engine control module.
6. Ignition OFF, connect the EL 34730-405 - Injector Test Lamp between the TAC motor control 1 circuit terminal B and TAC motor control 2
circuit terminal A of the throttle body harness connector. Observe the injector test lamp while turning the ignition ON for 5 s and then OFF.
Verify the injector test lamp illuminates brightly and then turns OFF.
瀚慖f the injector test lamp does not illuminate, replace the engine control module.
7. If all circuits test normal, replace the throttle body.
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Throttle Body Assembly Replacement (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and
Repair/Removal and Replacement)Throttle Body Assembly Replacement (LLT) (See: Powertrain Management/Fuel Delivery and Air
Induction/Throttle Body/Service and Repair/Removal and Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
* 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.
- Throttle Actuator Control (TAC) System - Forced Engine Shutdown
The engine control module (ECM) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control
(TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position (TP) sensors 1
and 2 to determine the actual throttle valve position.
Conditions for Running the DTC
* The ECM power down process in the last drive cycle was completely finished.
* DTC P2105 runs continuously once the above condition is met for greater than 5 seconds.
Conditions for Setting the DTC
* The ECM detects an incorrect voltage level at the ignition voltage supply circuits.
* The ECM detects an internal communication error.
* The condition exists, then a 5 second delay for MIL ON.
Action Taken When the DTC Sets
DTC P2105 is a Type A DTC.
Conditions for Clearing the DTC