Chevrolet Trax: DTC P1516, P2101, P2119, OR P2176

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

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) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position (TP) sensors 1 and 2 to determine the actual throttle valve position.

Conditions for Running the DTC

P1516

• DTC P1682 is not set.
• The run/crank or powertrain relay voltage is greater than 6.41 V and reduced power is not active.
• The desired throttle position remains steady for greater than 4 seconds.
• DTC P1516 runs continuously when the above conditions are met.

P2101

• DTC P1682 is not set.
• The run/crank or powertrain relay voltage is greater than 5.5 V and reduced power is not active.
• The engine is running or the following conditions are met:

• The engine is not running.
• The ignition voltage is greater than 11 V.
• The TAC system is not in the Battery Saver mode.
• The ECM is commanding the throttle.
• The ECM has learned the minimum throttle position.

• DTC P2101 runs continuously when the above conditions are met.

P2119

• The ignition is ON.
• DTC P0121, P0122, P0123, P0222, P0223, P0697, P06A3, or P2135 is not set.
• The run/crank or powertrain relay voltage is greater than 6.41 V and reduced power is not active.
• DTC P2119 runs continuously when the above conditions are met.

P2176

• The ignition is ON.
• The run/crank or powertrain relay voltage is greater than 6.41 V and reduced power is not active.
• The ECM enable the minimum throttle learn procedure.
• DTC P2176 run continuously when the above conditions are met.

Conditions for Setting the DTC

P1516

The ECM detects a difference of greater than 2 percent between the actual throttle position and the desired throttle position for greater than 1 s.

P2101

• The ECM detects a difference of greater than 10 percent between the actual throttle position and the predicted throttle position for greater than 1 s.

OR

• The ECM detects the throttle position is greater than 38 percent when throttle learn is active.

OR

• The ECM detects that the throttle position is greater than 50 percent when the engine is operating in reduced power mode.

P2119

The ECM detects the throttle blade did not return to the default position when the TAC motor is de-energized for greater than 1 s.

P2176

The ECM detects that both throttle position sensors are greater than 0.96 V for 2 s or greater, after 10 attempts to learn the minimum throttle position.

Action Taken When the DTC Sets

• DTCs P2101 and P2176 are Type A DTCs.
• DTC P1516 is a Type B DTC - with LUV.
• DTC P1516 is a Type C DTC - with LUJ.
• 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

• DTCs P2101 and P2176 are Type A DTCs.
• DTC P1516 is a Type B DTC - with LUV.
• DTC P1516 is a Type C DTC - with LUJ.
• DTC P2119 is a Type C DTC.

Diagnostic Aids

• Depending on the Start Up ECT, the Desired Throttle Position percentage maybe greater or less than the Throttle Position with the TAC motor at rest. When the ignition is initially turned ON, or when the engine is cranking or running the Desired and Actual Throttle positions should closely match.
• 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.
• A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
• A low battery condition may cause a DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

NOTE: A low battery voltage or charging system condition may cause a DTC to set.

2. Verify DTC P0121, P0122, P0123, P0222, P0223, P0562, P0621, P0622, or P2135 is not set.

• If any of the DTCs are set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

• If none of the DTCs are set

3. Verify the scan tool Throttle Body Idle Air flow Compensation parameter is less than 90 %.

• If 90 % or greater

Refer to Throttle Body Inspection and Cleaning .

• If less than 90 %

4. Clear the DTCs with a scan tool.
5. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
6. Ignition ON.
7. Verify the scan tool TAC Motor parameter displays Enabled while slowly depressing the accelerator pedal.

• If Enabled is not displayed

Refer to Circuit/System Testing.

• If Enabled is displayed

8. Verify DTC P1516, P2101, P2119, or P2176 is not set.

• If any of the DTCs are set

Refer to Circuit/System Testing.

• If none of the DTCs are set

NOTE: If there is a condition with the throttle body, the TAC Motor Command parameter will go to 99 % for a predetermined amount of time and then a DTC sets. Once a DTC is set, the TAC Motor Command parameter will go to 0 % and the TAC Motor parameter will display Disabled.

9. Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool.

• If Enabled is not displayed

Test or replace the Q38 Throttle Body assembly.

• If Enabled is displayed

10. 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.
11. Verify the DTC does not set.

• If the DTC sets

Refer to Circuit/System Testing.

• If the DTC does not set

12. All OK.

Circuit/System Testing

1. Ignition OFF.

WARNING: Turn OFF the ignition before inserting fingers into the throttle bore.

Unexpected movement of the throttle blade could cause personal injury.

2. Verify the conditions listed below do not exist with the Q38 Throttle Body assembly:

NOTE:

• The rest position is defined as the actual Throttle Position percentage when the ignition is OFF or with the ignition ON for greater than 30 seconds.
• When the ignition is OFF, spring tension should hold the throttle plate in the rest position. You should be able to open the throttle plate to wide open throttle (WOT) or push the throttle plate to the fully closed position. In each case, the throttle plate should return to the rest position without assistance.
• A throttle blade that is not in the rest position
• A throttle blade that is binding open or closed
• A throttle blade that is free to move open or closed without spring pressure
• If a condition is found

Test or replace the Q38 Throttle Body Assembly

• If a condition is not found

3. Ignition OFF.

NOTE:

• Disconnecting the throttle body harness connector may cause additional DTCs to set.
• The Test Lamp must be connected to circuit before turning ignition on or incorrect diagnosis may occur.

4. Disconnect the harness connector at the Q38 Throttle Body assembly.
5. Cycle the Ignition ON and OFF and then ON again.
6. Verify that a test lamp illuminates between each motor control circuit listed below and ground.

• TAC Motor Control Closed circuit terminal A
• TAC Motor Control Open circuit terminal B
• If the test lamp does not illuminate

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the appropriate control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance

3. Test for less than 2 ohms on the control circuit from end to end.

• If greater than 2 ohms, repair the open or high resistance on the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If the test lamp illuminates

7. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
8. Test for less than 1 V between each motor control circuit listed below and ground.

• TAC Motor Control Closed circuit terminal A
• TAC Motor Control Open circuit terminal B
• If greater than 1 V

Repair the short to voltage on the circuit.

• If less than 1 V

9. Test or replace the Q38 Throttle Body assembly.

Repair Instructions

• Throttle Body Assembly Replacement
• Control Module References for Engine Control Module replacement, programming, and setup

Repair Verification

1. Ignition OFF.
2. Install any components that have been removed or replaced during diagnosis.
3. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
4. Ignition ON.
5. Clear the DTCs with a scan tool.
6. Turn the ignition OFF for 60 s.
7. Ignition ON.
8. Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool.

• If Enabled is not displayed

Test or replace the Q38 Throttle Body assembly.

• If Enabled is displayed

9. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not set.

• If DTC sets

Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

• If DTC does not set

10. All OK.

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