P050A

DTC P0506, P0507, or P050A

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

DTC P050A
- Cold Start Idle Air Control (IAC) System Performance




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. If the ECM detects the actual idle speed and the desired idle speed are not within a predetermined amount, this DTC sets.


Conditions for Running the DTC


P0506 and P0507
* DTC P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0221, P0222, P0223, P0442, P0443, P0446, P0455, P0458, P0459, P0496, or P0700 is not set.
* The vehicle speed is 0 km/h (0 mph).
* The evaporative emission (EVAP) canister purge valve is OFF.
* The intake air temperature (IAT) is greater than -11°C (+13°F).
* The engine coolant temperature (ECT) is greater than -11°C (+13°F).
* A vehicle speed was detected prior to the diagnostic running.
* DTC P0506 and P0507 run continuously once the above conditions are met for greater than 10 seconds.



P050A
* DTC P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0221, P0222, P0223, P0442, P0443, P0446, P0455, P0458, P0459, P0496, P0722, or P0723 is not set.
* The ECT is -10 to +40°C (+14 to +104°F) at cold start.
* The engine coolant temperature is less than 80°C (176°F) for the duration of the test.
* DTC P050A runs once an ignition cycle when the conditions above have been met for 7 seconds.



Conditions for Setting the DTC

P0506

The actual engine speed is less than the desired idle speed by at least 100 RPM for 5 seconds or for a cumulative of 50 seconds.


P0507
* The actual engine speed is greater than the desired idle speed by at least 200 RPM for 5 seconds or for a cumulative of 50 seconds.
OR
* The ECM detects 3 fuel cut-offs due to an engine over speed condition while the engine is idling.


P050A

The actual engine speed is greater or less than the desired idle speed by at least 100 RPM for 7 seconds or for a cumulative of 50 seconds, during a cold start.


Action Taken When the DTC Sets

DTCs P0506, P0507, and P050A are Type B DTCs.


Conditions for Clearing the DTC

DTCs P0506, P0507, and P050A are Type B DTCs.


Diagnostic Aids

Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore.


Reference Information
Schematic Reference

Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
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. Observe the DTC information with a scan tool.

• If there are any throttle actuator control (TAC), throttle position (TP) sensor, or accelerator pedal position (APP) sensor DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) .

2. Operate the engine within the conditions for running the DTCs for 1 minute. DTC P0506, P0507, or P050A should not set.
3. 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

Engine operating, command the engine speed up to 1,400 RPM, down to 600 RPM, up to 1,400 RPM, and then exit using the scan tool. The engine speed should steadily increase and decrease as commanded.

If the idle does not increase or decrease steadily, verify that one of the following conditions is not present:


* Vacuum leaks
* The throttle valve for the correct operation-A throttle valve that does not close correctly sets this DTC.
* Restricted air intake system
* The throttle body for damage and/or tampering
* Incorrect or malfunctioning PCV valve
* Excess deposits in the throttle body
* A parasitic load on the engine-For example, a transmission condition, a belt driven accessory condition

• Repair the condition as necessary.




Repair Instructions

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