• Perform the Diagnostic System Check prior to using this diagnostic procedure:Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis:Strategy Based Diagnosis
• An overview of each diagnostic category can be found here:Diagnostic Procedure Instructions

The engine control module (ECM) determines the driver's intent based on input from the accelerator pedal position sensors, then calculates the appropriate throttle response based on the throttle position sensors.

• DTC P0606, P1682 = Not set
• Desired Throttle Position=Steady State—For greater than 4 s
• Ignition Voltage=Greater than 6.4 V
• Reduced Engine Power=Not Activated

Frequency the DTC runs=Continuously—After the running conditions are met

• DTC P0606, P1682 = Not set
• Engine=Running
• Ignition Voltage=Greater than 5.5 V
• Reduced Engine Power=Not Activated

• Battery Saver Mode=Not Activated
• Engine=Not Running
• Ignition Voltage=Greater than 8.4 V
• Throttle Position=Learned
• Throttle Actuator Control System=Active

Frequency the DTC runs=Continuously—After the running conditions are met

• DTC P0122, P0123, P0222, P0223, P06A3 = Not set
• Battery Saver Mode=Not Activated
• Ignition Voltage=Greater than 5.5 V
• Reduced Engine Power=Not Activated
• Throttle Actuator Control System=Not Activated

Frequency the DTC runs=Continuously—After the running conditions are met

• Ignition Voltage=Greater than 6.4 V
• Reduced Engine Power=Not Activated
• Throttle Position Learn=Active

Frequency the DTC runs=Continuously—After the running conditions are met—For greater than 2 s

The following parameters are not within 2% of each other:

• Desired Throttle Position
• Throttle Position

The following parameters are not within 10% of each other:

• Desired Throttle Position
• Throttle Position

• Throttle Position Learn=Active
• Throttle Position=Greater than 53%

Blade@Q38 Throttle Body¿Closed@Engine Off

Minimum Throttle Position Not Learned=Exceeded Number of Attempts

DTCs listed in the DTC Descriptor category=Type A DTC—Exceptions listed below—Additional actions taken:

DTC P2101, P2176=Type A DTC

• Reduced Engine Power=Active
• Warning Message=Reduced Engine Power
• Under certain conditions, the control module commands the engine Off.

DTC P1516, P2119=Type B DTC—No additional actions taken

• DTC P2101, P2176=Type A DTC
• DTC P1516, P2119=Type B DTC

• A high resistance condition on the component circuits may cause the DTC to set.
• A weak battery may cause this DTC to set.
• If the throttle blade becomes stuck, a DTC will set. Depending on the position of the throttle blade, the engine control module (ECM) may enter Engine Shutdown Mode. The ECM will disable fuel and de-energize the throttle actuator. If the condition remains present during the next ignition cycle, the ECM may disable engine cranking. Inspect the throttle body assembly for a stuck throttle blade if a throttle actuator DTC is current and the engine won't crank.
• Inspect for a condition in which the throttle blade may have been held open. For example, ice may have formed in the throttle bore causing the throttle blade not to close.
• Under cold start conditions, it might happen briefly that the desired and the actual throttle blade position do not match.

Engine Controls Schematics

Master Electrical Component List

Throttle Actuator Control (TAC) System Description

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

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Control Module References

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P0068, P0121, P0122, P0123, P0222, P0223, P0562, P06A3, P0606, P0607, P0621, P0622, P16A0-P16A2, P2135, U0606, U0607 is not set
• If any of the DTCs are set

  Refer to:Diagnostic Trouble Code (DTC) List - Vehicle

• If none of the DTCs are set
3. Verify the scan tool parameter:Throttle Body Idle Air Flow Compensation=Less than 90%
• If 90% or greater

  Refer to:Throttle Body Inspection and Cleaning.

• If less than 90%
4. Perform the following action:Clear the DTCs.
5. Ignition/Vehicle » Off
6. Ignition » On / Vehicle » In Service Mode
7. Perform the scan tool control function:Throttle Sweep»Start

   Verify the scan tool parameter:TAC Motor=Enabled

• If not the specified state

  Refer to: Circuit/System Testing

• If the specified state
8. Verify the scan tool parameter:TAC Motor=Enabled

   Perform the action while monitoring the parameter:

• Wiggle the harness and connector(s):Q38 Throttle Body
• Wiggle the harness and connector(s):K20 Engine Control Module
• If not the specified state

  Repair as necessary » Wiring / Terminal(s) / Electrical Connector(s)

• If the specified state
9. 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.

   Verify the DTC does not set.

• If the DTC sets

  Refer to: Circuit/System Testing

• If the DTC does not set
10. All OK.

1. Ignition/Vehicle » Off
2. Verify the following conditions do not exist:

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

• Binding or Sticking@Open/Closed—Position
• Open@Engine Off
• Closed—Without spring pressure
• If a condition exists

  Replace the component:Q38 Throttle Body

• If no condition exists

Note: Disconnecting the component electrical connector causes additional DTCs to set.

3. Disconnect the electrical connector:Q38 Throttle Body
4. Ignition » On / Vehicle » In Service Mode
5. Test for 6 to 9 V between the test points:
• Control circuit terminal 1&Ground
• Control circuit terminal 2&Ground
• If less than 6 V
1. Ignition/Vehicle » Off
2. Disconnect the appropriate electrical connector:K20 Engine Control Module
3. Test for infinite resistance between the test points:
• Control circuit terminal 1@Component harness&Ground
• Control circuit terminal 2@Component harness&Ground
• If less than infinite resistance » Repair the short to ground on the circuit.
• If infinite resistance
4. Test for less than 2 Ω between the test points:
• Control circuit terminal 1@Component harness&The other end of the circuit@Control module harness
• Control circuit terminal 2@Component harness&The other end of the circuit@Control module harness
• If 2 Ω or greater » Repair the open/high resistance in the circuit.
• If less than 2 Ω » Replace the component:K20 Engine Control Module
• If greater than 9 V
1. Ignition/Vehicle » Off
2. Disconnect the appropriate electrical connector:K20 Engine Control Module
3. Ignition » On / Vehicle » In Service Mode
4. Test for less than 1 V between the test points:
• Control circuit terminal 1@Component harness&Ground
• Control circuit terminal 2@Component harness&Ground
• If 1 V or greater » Repair the short to voltage on the circuit.
• If less than 1 V » Replace the component:K20 Engine Control Module
• If between 6 and 9 V
6. Ignition/Vehicle » Off
7. Disconnect the appropriate electrical connector:K20 Engine Control Module
8. Test for less than 2 Ω between the test points:
• Control circuit terminal 1@Component harness&The other end of the circuit@Control module harness
• Control circuit terminal 2@Component harness&The other end of the circuit@Control module harness
• If 2 Ω or greater

  Repair the open/high resistance in the circuit.

• If less than 2 Ω
9. Test or replace the component:Q38 Throttle Body

Perform the Diagnostic Repair Verification after completing the repair:Diagnostic Repair Verification

• Throttle Body Assembly Replacement
• For control module replacement, programming, and setup refer to:Control Module References