With Throttle Actuator Control

DTC P0506 or P0507 (w/ Throttle Actuator Control)

Diagnostic Instructions

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

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. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

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 after completing the diagnostic procedure. Verification Tests

* Throttle Body Assembly Replacement
* Programming and Relearning for ECM setup, and programming Programming and Relearning