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Home >> Chevrolet >> 2006 >> Cobalt L4-2.4L VIN B >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P1516

P1516



DTC P1516

DTC DESCRIPTORS

DTC P1516
Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance

DTC P2101
Throttle Actuator Position Performance

DTC P2119
Throttle Closed Position Performance

DTC P2176
Throttle Closed Position Performance

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






CIRCUIT/SYSTEM DESCRIPTION
The engine control module (ECM) is the control center for the 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 system uses the following circuits:
- Motor control 1
- Motor control 2

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

CONDITIONS FOR RUNNING THE DTC

P1516 and P2101
- The ignition is ON.
- The ignition voltage is more than 8 volts.
- The system is not in the Battery Save mode.
- The engine is running.
- DTC P0068 is not set.
- DTC P1516 and P2101 run continuously when the above conditions are met.

P2119
- The ignition is ON.
- The ignition voltage is more than 8 volts.
- The system is in the Battery Save mode.
- DTC P2119 runs continuously when the above conditions are met.

P2176
- The ignition is ON.
- The ignition voltage is more than 8 volts.
- The system is not in the Battery Save mode.
- The engine is running.
- DTCs P0068, P0120, P0122, P0123, P0220, P0222, P0223 are not set.
- DTC P2176 run continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC

P1516
The indicated throttle position does not match the predicted throttle position for more than 0.5 second.

P2101
The indicated throttle position does not match the predicted throttle position for more than 0.3 second.

P2119
The ECM determines that the throttle blade did not return to the rest position within 720 milliseconds.

P2176
The difference between the predicted and the actual throttle position is more than a calibrated amount for more than 1.5 seconds.

ACTION TAKEN WHEN THE DTC SETS

P1516, P2101, and P2176
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

P2119
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The MIL will not illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
- The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
Ignition ON, use a scan tool to observe the throttle position (TP) 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.

CIRCUIT/SYSTEM TESTING
1. Inspect the 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 is free to move open or closed WITHOUT spring pressure
2. Ignition ON, and the throttle body disconnected, measure for voltage on the motor control 1 and 2 circuits. Voltage should be 0 volts.
- If voltage is more than 0 volts, test the affected motor control circuit for a short to voltage or a faulty ECM.
3. Ignition ON, and the throttle body disconnected, probe the motor control 1 and 2 circuits with a test lamp connected to B+. Test lamp should not illuminate
- If test lamp illuminates, test the affected motor control circuit for a short to ground.
4. With the ignition ON, and the throttle body connected, clear DTCs.
5. With the ignition OFF, disconnect the throttle body and connect a DMM between the motor control 1 circuit and ground.
6. Using the peak min max function measure the voltage on the motor control 1 circuit as the ignition is turned ON. Voltage should be within 1 volt of ignition voltage.
- If voltage is not within 1 volt of ignition voltage, test for a faulty ECM.
7. With the ignition ON, and the throttle body connected, clear DTCs.
8. With the ignition OFF, disconnect the throttle body and connect a DMM between the motor control 2 circuit and ground.
9. Using the peak min max function measure the voltage on the motor control 2 circuit as the ignition is turned on. Voltage should be within 1 volt of ignition voltage.
- If voltage is not within 1 volt of ignition voltage, test for a faulty ECM.
- If all circuits test normal, replace the throttle body.

REPAIR INSTRUCTIONS
- Control Module References for ECM replacement, setup, and programming
- Throttle Body Assembly Replacement

REPAIR VERIFICATION
Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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