Cruze

DTC P2100, P2101, P2108, P2119, or P2176

The engine control module (ECM) is the control centre for the throttle body throttle actuator control (TAC) system. The ECM determines the drivers intent and then calculates the appropriate throttle response. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor. The TAC motor system uses the following circuits:

Two processors are also used to monitor the TAC motor system data. Both processors are located within the ECM. Both processors monitor each others data to verify that the indicated throttle position is correct.

P2100 00

P2101 00, P2119 00, P2176 00

P2108 00

P2100 00

The indicated throttle position does not match the predicted throttle position for more than 0.5 s.

P2101 00, P2108 00

The indicated throttle position does not match the predicted throttle position for more than 0.3 s.

P2119 00

The ECM determines that the throttle blade did not return to the rest position within 720 ms.

P2176 00

The difference between the predicted and the actual throttle position is more than a calibrated amount for more than 1.5 s.

Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, engine OFF, use a scan tool to observe the throttle position sensor 1 indicated position. Throttle position should increase as pedal is applied and decrease as pedal is released. When no accelerator pedal activity is detected, the throttle position will return to the spring loaded default position.
2. DTC P2176 is an informational DTC. Perform the throttle learn procedure, refer to Throttle/Idle Learn .
3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

1. Inspect the Q38 Throttle Body for the following conditions:

•	A throttle blade that is not in the rest position

•	A throttle valve that is binding open or closed

•	A throttle valve that opens or closes without spring pressure

⇒	If a condition is found, replace the Q38 Throttle Body.

Note: Disconnecting the throttle body harness connector causes additional DTCs to set.

2. Ignition OFF, disconnect the harness connector of the Q38 Throttle Body.
3. Ignition ON, test less than 0.3 V between the Q38 Throttle Body Motor Control Circuit terminal 3 X1 and ground.

⇒	If greater than 0.3 V, test the Q38 Throttle Body Motor Control Circuit terminal 3 X1 for a short to voltage.

⇒	If the circuit tests normal, replace the K20 Engine Control Module.

4. Ignition ON, test for less than 0.3 V between the Q38 Throttle Body Motor Control Circuit terminal 5 X1 and ground.

⇒	If greater than 0.3 V, test the Q38 Throttle Body Motor Control Circuit 5 X1 for a short to voltage.

⇒	If the circuit tests normal, replace the Q38 Throttle Body.

5. Verify that a test lamp does not illuminate between Q38 Throttle Body Motor Control Circuit terminal 3 X1 and B+.

⇒	If test lamp illuminates, test the Q38 Throttle Body Motor Control Circuit terminal 3 X1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

6. Verify that a test lamp does not illuminate between motor control circuit terminal 5 X1 and B+.

⇒	If test lamp illuminates, test the Q38 Throttle Body Motor Control Circuit terminal 5 X1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

7. Ignition OFF for 90 s. Connect a DMM between the Q38 Throttle Body Motor Control Circuit terminal 3 X1 and ground.

Note: When measuring peak voltage, ensure that the DMM is on the proper voltage scale that the response time is set to 1 ms.

8. Ignition ON, test for 4-5 V on the Q38 Throttle Body Motor Control Circuit terminal 3 X1 and ground.

⇒	If less than the specified range, test for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

9. Ignition OFF for 90 s. Connect a DMM between the motor control terminal 5 X1 circuit and ground.
10. Ignition ON, test for 4-5 V on the Q38 Throttle Body Motor Control Circuit terminal 5 X1 and ground.

⇒	If less than the specified range, test for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

11. If all circuits test normal, replace the Q38 Throttle Body.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.