P0506
DTC P0506 or P0507
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 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 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 P0068, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0300-P0308, P0351-P0358, P0461-P0463, P0496, P0502, P0503, P0606, P06A3, P0722, P0723, P0806-P0808, P1516, P2066-P2068, P2101, P2122, P2123, P2127, P2128, P2135, P2138, P2227-P2230 are not set.
* The engine is operating for at least 60 s.
* The engine is idling for greater than 10 s.
* The barometric pressure (BARO) is greater than 70 kPa (11 psi).
* The engine coolant temperature (ECT) is greater than 60°C (140°F) - Without HD L96.
* The engine coolant temperature (ECT) is greater than 60-125°C (140-257°F) - With HD L96.
* The intake air temperature (IAT) is warmer than -20°C (-4°F).
* The vehicle speed is less than 3 km/h (2 mph).
* The commanded engine speed is steady within 25 RPM.
* The transmission is not changing gears.
* The torque converter clutch (TCC) is not changing states.
* The manual transmission clutch pedal position is between 20-88 percent - With HD L96, If equipped.
* The manual transmission clutch pedal position top of travel is greater than 5 percent - Without HD L96, If equipped.
* The manual transmission clutch pedal position bottom of travel is less than 5 percent - Without HD L96, If equipped.
* The manual transmission clutch is not depressed - If equipped.
* The power take-off (PTO) is not active - If equipped.
* The transfer case is not in 4WD Low - If equipped.
* A scan tool output control is not active.
* The system voltage is between 11-32 V.
* DTC P0506 and P0507 run continuously when the above conditions are met for greater than 10 s.
Conditions for Setting the DTC
P0506
The actual idle speed is approximately 90 RPM lower than the desired idle speed.
P0507
The actual idle speed is approximately 180 RPM greater than the desired idle speed.
Action Taken When the DTC Sets
DTCs P0506 and P0507 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs 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 (except L96) [1][2]Electrical DiagramsEngine Controls Schematics (L96) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
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 References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify there are no other DTCs set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
Note: The engine must run for greater than 60 s, then idle at a steady state for an additional 10 s before comparing the actual and desired engine speed parameters.
2. Idle the engine at the normal operating temperature. Compare the Desired Idle Speed to the actual Engine Speed with a scan tool. The actual Engine Speed should not be less than 100 RPM of the Desired Idle Speed or 200 RPM greater than the Desired Idle Speed.
3. Allow the engine to idle within the Conditions for Running the DTC. DTC P0506 or P0507 should not set.
4. 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
Verify none of the following conditions exist:
P0506
* Excess deposits in the Q38 throttle body. Refer to Throttle Body Cleaning Procedures
* Restricted exhaust
* Mechanical conditions that limits engine speed
* Parasitic load on the engine-For example, a transmission condition, a belt driven accessory condition.
• If a condition is found, repair as necessary.
P0507
* Vacuum leaks
* A throttle valve that does not close correctly
* 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-Refer to Crankcase Ventilation System Inspection/Diagnosis Testing and Inspection
• If a condition is found, repair as necessary.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.