W/TAC

DTC P0506 or P0507 (w/TAC)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0506
- Idle Speed Low

DTC P0507
- Idle Speed High

Circuit/System Description

The throttle actuator control (TAC) motor is a DC motor that is part of the throttle body assembly. The TAC motor drives the throttle valve. The engine control module (ECM) controls the TAC motor based on throttle position sensor input. The idle speed is controlled by the ECM based on various inputs. The ECM commands the TAC motor to open or close the throttle valve in order to maintain the desired idle speed.

Conditions for Running the DTC

* The engine is idling.
* The engine run time is greater than 2 seconds.
* The evaporative emission (EVAP) purge flow is less than 100 percent.
* The barometric pressure (BARO) is greater than 72 kPa.
* The intake air temperature (IAT) is greater than -20°C (-4°F).
* The engine coolant temperature (ECT) is greater than -10°C (+14°F).
* The ignition voltage is between 11-16 volts.
* The DTCs run when the above conditions are met for 3 seconds.

Conditions for Setting the DTC

P0506

The actual engine speed is less than the desired idle speed by at least 100 RPM for 10 seconds.

P0507

The actual engine speed is greater than the desired idle speed by at least 200 RPM for 10 seconds.

Action Taken When the DTC Sets

DTCs P0506, and P0507 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0506, and P0507 are Type B DTCs.

Reference Information
Schematic Reference

Engine Controls Schematics (Electrical Diagrams)
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

1. Allow the engine to idle within the conditions for running the DTCs for 1 minute. DTCs P0506 or P0507 should not set.
2. 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

P0506
* Inspect the engine for vacuum leaks.
* Inspect the throttle valve for the correct operation. A throttle valve that does not close correctly sets this DTC.
* Verify the correct operation of the crankcase ventilation system. Inspect for the following conditions:

- The routing of the positive crankcase ventilation (PCV) system
- Vacuum leaks in the PCV system

P0507
* Inspect for excess deposits in the throttle body.
* Inspect for a parasitic load on the engine-For example, a transmission condition, a belt driven accessory condition.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

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