FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Hummer >> 2010 >> H3 L5-3.7L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P2176

P2176




DTC P1516, P2101, P2119, or P2176

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (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 and P2101
* DTC P0606 or P1682 is not set.

Engine Running
* The ignition voltage is greater than 5.5 V.
* The engine is running.

Engine Not Running
- The engine is not running.
- The TAC system is not in the Battery Saver mode.
- The ignition voltage is greater than 11 V.
- The ECM is commanding the throttle.
- The minimum throttle position learn is not active.

* DTC P1516 and P2101 run continuously when the above conditions are met.

P2119
* The ignition is in the unlock, accessory, run, or crank position.
* The ignition voltage is greater than 8 V.
* The system is in the Battery Save mode.
* DTC P2119 runs continuously when the above conditions are met.

P2176
* DTC P0120, P0122, P0123, P0220, P0222, P0223, or P1682 are not set.
* The ignition is ON.
* The ignition voltage is greater than 8 V.
* The system is not in the Battery Save mode.
* 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 greater than 0.5 s.

P2101

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

P2119

The ECM determines that the throttle blade did not return to the rest position within 0.720 s.

P2176

The difference between the predicted and the actual throttle position is greater than a calibrated amount for greater than 1.5 s.

Action Taken When the DTC Sets

* DTCs 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

* DTCs P1516, P2101, and P2176 are Type A DTCs.
* DTC P2119 is a Type C DTC.

Diagnostic Aids

* If the Throttle Sweep Test is not available on the scan tool, observe the scan tool TAC Motor parameter while performing the following tests:

- Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times.
- Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times.
The TAC Motor parameter should display Enabled. If Disabled is displayed, continue diagnosis in Circuit/System Testing.

* 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 ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Throttle Actuator Control (TAC) System Description (Throttle Actuator Control (TAC) System Description)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

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

1. Ignition ON, observe the DTC information with a scan tool. DTC P0120, P0122, P0123, P0220, P0222, P0223, P0562, P0621, P0622, or P2135 should not set.

• If a DTC sets, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) for further diagnosis.

2. Clear the DTCs with a scan tool. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
3. Ignition ON, observe the scan tool TAC Motor parameter. The reading should display Enabled.
4. Observe the DTC information with a scan tool. DTC P1516, P2101, P2119, or P2176 should not set.

Note:
* If the Throttle Sweep Test is not available on the scan tool, use the accelerator to perform the test. Refer to Diagnostic Aids for further details.
* 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.

5. Perform the Throttle Sweep Test while observing the TAC Motor parameter with a scan tool. The TAC Motor parameter should display Enabled while the Throttle Sweep Test is in progress.

Note: Before replacing the throttle body assembly, make sure the throttle control circuits are not shorted to B+.

• If not the specified value, replace the throttle body assembly.

6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Warning

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

1. Ignition OFF, inspect the throttle body for the following conditions:

* 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, replace the throttle body assembly.

Note: Disconnecting the throttle body harness connector causes additional DTCs to set.

2. Ignition OFF, disconnect the harness connector at the throttle body.
3. Ignition ON, verify that a test lamp does not illuminate between each control circuit listed below and ground.

* TAC Motor Control Closed circuit terminal A
* TAC Motor Control Open circuit terminal B

• If test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Ignition ON, verify that a test lamp does not illuminate between each control circuit listed below and B+.

* TAC Motor Control Closed circuit terminal A
* TAC Motor Control Open circuit terminal B

• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

5. Ignition OFF, set the DMM to the 40 V scale, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms.

Note:
* The DMM Min/Max Recording Mode and the response time of 1 ms must be reset after testing each circuit or a lower voltage will be recorded.
* The ignition must be OFF and the ECM completely powered down before testing each circuit or a lower voltage will be recorded.

6. Ignition OFF, measure the voltage using the DMM Min/Max Recording Mode function on each circuit listed below as the ignition is turned ON. The Max voltage should be within 1 V of B+.

* TAC Motor Control Closed circuit terminal A
* TAC Motor Control Open circuit terminal B

• If not within the specified range, test the circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

7. If all circuits and connections test normal, replace the throttle body assembly.

Repair Instructions

* Throttle Body Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming

Repair Verification

1. Install any components that have been removed or replaced during diagnosis.
2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
3. Clear the DTCs with a scan tool.
4. Turn OFF the ignition for 60 seconds.

Note: If the Throttle Sweep Test is not available on the scan tool, use the accelerator to perform the test. Refer to Diagnostic Aids for further details.

5. Perform the Throttle Sweep Test while observing the TAC Motor parameter with a scan tool. The TAC Motor parameter should display Enabled while the Throttle Sweep Test is in progress.
6. 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 reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) and perform the appropriate diagnostic procedure.

pro multis Credits:Operation CHARM About Operation CHARM