P0506
DTC P0506 or P0507 (LUW)
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 Instructionsprovides 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 controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the ECM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the ECM commands the throttle plate open allowing more air to pass the throttle plate.
Conditions for Running the DTC
* DTCs P0107, P0108, P0117, P0118, P0122, P0123, P0128, P0171, P0172, P0201, P0202, P0203, P0204, P0222, P0223, P0300, P0403, P0404, P0405, P0406, P0496, P0601, P0604, P0606, P0641, P2101, P2119, P2122, P2123 00, P2127, P2128, P2138, or P2176 are not set.
* The engine has been running for greater than 60 s.
* The engine is idling for greater than 5 s.
* The intake air temperature (IAT) is greater than -20°C (-4°F).
* The transmission gear selector state has not changed.
* The engine coolant temperature (ECT) is greater than 60°C (140°F).
* The system voltage is between 11-32 V.
* The vehicle speed is less than 3.2 km/h (2 MPH).
* DTCs P0506 or P0507 run continuously when the above conditions are met.
Conditions for Setting the DTC
P0506
* The ECM detects that the actual idle speed is continuously approximately 91 RPM lower than the desired idle speed.
* The above condition is present for 15 s.
P0507
* The ECM detects that the actual idle speed is approximately 182 RPM higher than desired idle speed.
* The above condition is present for 15 s.
Action Taken When the DTC Sets
DTC P0506 and P0507 are Type B DTCs.
Conditions for Clearing the DTC
DTC P0506 and P0507 are Type B DTCs.
Diagnostic Aids
* A stalling condition can cause DTC P0506 to set.
* An intermittent vehicle speed sensor (VSS) signal can cause DTC P0507 to set.
* An intermittent clutch pedal position sensor signal, if equipped, can cause DTC P0506 to set.
Reference Information
Schematic Reference
Engine Controls Schematics (LUW) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (D6I)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module Referencesfor scan tool information
Circuit/System Verification
Note: The engine must first be running for greater than 60 s, then idle at a steady state for an additional 10 s before comparing the actual and desired engine idle speed parameters.
1. Using a scan tool compare the Desired Idle Speed parameter to the actual Engine Speed parameter.
* Actual engine speed should not be less than 100 RPM below desired.
* Actual engine speed should not be greater than 200 RPM above desired.
2. Verify that there are no other DTCs set.
• If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
3. 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.
Circuit/System Testing
1. Inspect for any condition that can reduce idle speed by increasing engine load.
* Incorrect torque converter clutch (TCC) operation
* Accessories that require additional torque to operate
* More deposits than the customer may desire in the Q38 Throttle Body
* Restricted exhaust
* Mechanical conditions that limit engine speed
• Repair any conditions, if necessary.
2. Inspect for the following conditions:
* Vacuum leaks
* A faulty positive crankcase ventilation valve
• Repair any conditions, if necessary.
Repair Verification
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Throttle Body Inspection and Cleaning (1.6L LDE, LXV, 1.8L 2H0, and LUW) Procedures