P0506
DTC P0506 or P0507
Circuit Description
The DTC P0506 idle Speed Low diagnostic monitors the engine speed. The powertrain control module (PCM) controls the idle air control (IAC) valve in order to regulate the air flow through the idle air bypass passage. The amount of air flowing through the idle air bypass passage determines the idle speed. The PCM directs the IAC valve according to changes in the engine load. A stalling or poor idle concern may be caused by the IAC valve not operating properly.
DTC Descriptors
This diagnostic procedure supports the following DTC. DTC P0506 Idle Speed Low
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0171, P0172, P0174, P0175, P0452, P0453, P0502, P0503, P0641, P0651, P1111, P1112, P1114, P1115, P1121, P1122, P1133, P1134, P1153, and P1154 are not set.
- The system voltage is between 9-18 volts.
- The startup ECT is more than 60°C (39-86°F).
- The startup IAT is between 4-30°C (39-86°F).
- The start up ECT and IAT are within 8°C (14°F) of each other.
- The fuel tank level is between 15-85 percent.
- The startup barometric pressure (BARO) is more than 65 kPa.
- The vehicle speed sensor (VSS) is less than 90 km/h (75 mph).
- DTC P0507 runs once per ignition cycle when the above conditions are met.
Conditions for Setting the DTC
- The actual engine speed is 100 RPM less than the desired engine speed value with the IAC Motor Command near 0 percent.
- The above condition exists for more than 5 seconds.
Action Taken When the DTC Sets
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the
second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Inspect for the following conditions:
- High resistance in an AC circuit
- Restricted air intake system
- Proper operation and installation of all air intake components
- Collapsed, clogged, or loose air intake ducts
- A clogged air filter
- Proper operation of the mass air flow sensor, if equipped
- A tampered with or damaged throttle stop screw
- A tampered with or damaged throttle plate, throttle shaft, or throttle linkage
- Objects blocking the IAC passage or throttle bore
- Excessive deposits in the IAC passage or on the IAC pintle
- Excessive deposits in the throttle bore or on the throttle plate
- Vacuum leaks
- A low or unstable idle condition could be caused by a non-IAC system problem that can not be overcome by the IAC valve-Refer to Symptoms -Engine ControlsSymptom Related Diagnostic Procedures
If the problem is determined to be intermittent, refer to Intermittent Conditions.Symptom Related Diagnostic Procedures
Test Description
DTC P0506 or P0507 Steps 1-7:
DTC P0506 or P0507 Steps 7-10:
DTC P0506 or P0507 Steps 11-18:
The numbers below refer to the step numbers on the diagnostic table.
5. This test will determine the ability of the engine controller and the IAC valve circuits to control the IAC valve.
7. This test will determine the ability of the PCM to provide the IAC circuits with a ground. On a normally-operating system, the test lamp should not flash while the IAC counts are incrementing.