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P2176



DTC P2176

DTC DESCRIPTOR

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. Refer to Throttle Actuator Control (TAC) System Description.

CONDITIONS FOR RUNNING THE DTC

P1516 and P2101
- DTC P0068 or P0121 are not set.
- The ignition is ON.
- The ignition voltage is more than 11 volts.
- The system is not in the Battery Save mode.
- The engine is running.
- 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
- DTC P0068, P0120, P0122, P0123, P0220, P0222, or P0223 are not set.
- 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 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 0.2 second.

P2101
The indicated throttle position does not match the predicted throttle position for more than 0.1 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 1.8 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 malfunction indicator lamp (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
1. If DTCs P0120, P0122, P0123, P0220, P0222, P0223, P0689, P1682, or P2135 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis. Diagnostic Trouble Code Descriptions
2. With the ignition ON, observe the throttle position (TP) sensor 1 indicated position with a scan tool. The indicated position should increase as the pedal is applied and decrease as the 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 blade that is binding when opening or closing
- A throttle blade that is free to move in the open or closed positions WITHOUT spring pressure
- If a condition is found, replace the throttle body.
2. With the ignition ON and the throttle body harness disconnected, measure for 0 volts on the motor control 1 and 2 circuits.
- If the voltage is more than 0 volts, test the affected motor control circuit for a short to voltage. If the circuits test normal, replace the control module.
3. With the ignition ON, and the throttle body harness disconnected, probe the motor control 1 and 2 circuits with a test lamp connected to battery voltage. Verify the test lamp does not illuminate on either circuit.
- If the test lamp illuminates, test the affected motor control circuit for a short to ground. If the circuits test normal, replace the control module.
4. With the ignition ON and the throttle body connected, clear all DTCs.
5. Turn OFF the ignition and all electrical accessories. Allow sufficient time for the control module to power down before disconnecting the throttle body harness connector.
6. Connect the J 34730-405 between the TAC motor control 1 and TAC motor control 2 circuit of the throttle body harness connector. Momentarily start the engine and then turn OFF the ignition while you observe the test lamp for a brief flash ON and OFF. Repeat this procedure as necessary. Allow sufficient time for the control module to power down before each ignition cycle.
- If the J 34730-405 does not flash briefly ON and OFF, test TAC motor control 1 and TAC motor control 2 circuits for an open. If the circuits test normal, replace the control module.
- If the J 34730-405 does flash briefly ON and OFF during each engine start, test TAC motor control 1 and TAC motor control 2 circuits for a resistance value of less than 5 ohms. If the circuits test normal, replace the throttle body.

REPAIR INSTRUCTIONS
Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Control Module References for ECM replacement, setup, and programming
- Throttle Body Assembly Replacement Verification Tests
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