P0506
DTC P0506 or P0507
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy 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 controlled by the TAC module using various inputs from the powertrain control module (PCM) which are communicated across serial data. The DC motor located in the throttle body drives the throttle plate. In order to decrease idle speed, the TAC module commands the throttle closed, reducing air flow into the engine. In order to increase idle speed, the TAC module commands the throttle plate open, allowing more air to pass the throttle plate. If actual idle RPM does not match the desired idle RPM within a calibrated time, DTC P0506 or P0507 sets.
Conditions for Running the DTC
* DTCs P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0128, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0300, P0401, P0404, P0405, P0443, P0496, P0502-if applicable, P0503-if applicable, P1106, P1107, P1111, P1112, P1114, P1115, P1404, P1516, P2101, P2107, P2108, P2119, P2120, P2125, P2135, P2138, U0107 are not set.
* DTCs P0136, P0401 and P0420 have passed.
* The engine is idling for more than 1 second.
* The engine coolant temperature (ECT) is more than -40°C (-40°F).
* The intake air temperature (IAT) is more than -40°C (-40°F).
* The barometric pressure (BARO) is more than 60 kPa.
* The system voltage is between 11-18 volts.
* The vehicle speed is less than 4.8 km/h (3 mph).
* The throttle angel is less than 0.25 percent.
* DTC P0506 and P0507 run continuously when the above conditions are met.
Conditions for Setting the DTC
P0506
* The difference between the actual and desired idle RPM exceeds a calibrated limit. This limit varies from 300 RPM at -40°C (-40°F) to 100 RPM at 152°C (305°F) based on engine coolant temperature.
* The above condition is present for 8 seconds in order for the test to fail. Four tests must fail in order to set this DTC. The vehicle must exit condition for running between each test.
P0507
* The difference between the actual and desired idle RPM exceeds a calibrated limit. This limit varies from 300 RPM at -40°C (-40°F) to 175 RPM at 152°C (305°F) based on ECT.
* The above conditions must be present for 8 seconds in order for the test to fail. Four tests must fail in order to set this DTC. The vehicle must exit conditions for running between each test.
Action Taken When the DTC Sets
* DTC P0506 and P0507 are Type B DTCs.
* The control module commands the TAC system to operate in the Reduced Engine Power mode.
Conditions for Clearing the MIL/DTC
DTC P0506 and P0507 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Throttle Actuator Control (TAC) System Description (Throttle Actuator Control (TAC) System Description)
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. Using a scan tool, compare the desired engine idle speed to the actual engine idle speed.
• Actual engine idle speed should be no greater than 175 RPM below desired.
• Actual engine idle speed should be no greater than 175 RPM above desired.
2. 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. Observe the DTC information on the scan tool.
• If there are any other DTCs set, diagnose those first.
2. 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
* Excessive deposits in the throttle body
* Restricted exhaust
* Mechanical conditions that limit engine speed
• Repair any conditions, if necessary.
3. Inspect for the following conditions:
* Vacuum leaks
* A faulty positive crankcase ventilation (PCV) valve
Repair Verification
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.