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P1516



DTC P1516

DIAGNOSTIC INSTRUCTIONS
- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
- Strategy Based Diagnosis
- Diagnostic Procedure Instructions

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
Minimum Throttle Position Not Learned

DIAGNOSTIC FAULT INFORMATION






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
- 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
- DTC P1516, P2101, and P2176 are Type A DTCs.
- DTC P2119 is a Type C DTC.
- The control module commands the TAC system to operate in the Reduced Engine Power mode.
- A message center or an indicator displays Reduced Engine Power.
- Under certain conditions the control module commands the engine OFF.

CONDITIONS FOR CLEARING THE MIL/DTC
- DTC P1516, P2101, and P2176 are Type A DTCs.
- DTC P2119 is a Type C DTC.

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. Ignition ON, observe the throttle position (TP) sensor 1 and TP sensor 2 indicated position with a scan tool. The indicated position parameter 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.

CAUTION: Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.

2. 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 ECM.
3. 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 ECM.
4. Ignition ON and the throttle body connected, clear all DTCs.
5. Ignition OFF, allow sufficient time for the control module to power down before disconnecting the throttle body harness connector.
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 less than the specified range, test the motor control 1 circuit for high resistance. If the circuit tests normal, replace the ECM.
7. Ignition ON and the throttle body connected, clear the DTCs.
8. 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 less than the specified range, test the motor control circuit for high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, replace the throttle body.

REPAIR INSTRUCTIONS
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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