Cruze

DTC P1516, P2100-P2103, 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 throttle body (TAC) motor. The throttle body (TAC) motor system uses the following circuits:

Two processors are also used to monitor the throttle body (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.

P1516 00 or P2101 00

P2100 00, P2102 00, or P2103 00

P2119 00

P2176 00

P1516 00

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

P2100 00

The ECM detects the output circuit for the TAC motor is open, shorted to ground, or shorted to a voltage. The condition exists for greater than 1 s.

P2101 00

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

P2102 00

The ECM detects an over heating or over current condition. The condition exists for 1 s.

P2103 00

The ECM detects a throttle actuator circuit that is shorted. The condition exists for 1 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.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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.

Note: A low voltage condition may set this DTC.

2. Review the freeze frame/failure records and ensure sufficient ignition voltage was present when the DTC was set.

⇒	If voltage was low, verify with the owner that the battery was not discharged. If the battery has not been discharged, refer to Power Mode Mismatch

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 for greater than 2-3 V on the Q38 Throttle Body motor control 1 circuit terminal A and Q38 Throttle Body motor control 2 circuit terminal B.

⇒	If less than the specified range, test the appropriate Q38 Throttle Body motor control circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

4. Ignition ON, probe the Q38 Throttle Body motor control 1 circuit terminal A and Q38 Throttle Body motor control 2 circuit terminal B with a test lamp connected to ground. Verify the test lamp does not illuminate.

⇒	If the test lamp illuminates, test the appropriate Q38 Throttle Body motor control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

5. Set the DMM to Alternating Current (AC) Hz on the 400 mV scale. Engine idling, test for greater than 2000 AC hz between the Q38 Throttle Body motor control circuits listed below and ground while commanding the Engine Speed to 1 950 RPM with a scan tool.

•	Motor control 1 circuit terminal A

•	Motor control 2 circuit terminal B

⇒	If less than the specified value, replace the K20 Engine Control Module.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.