For 1990-2009 cars only
Circuit Description
The engine control module (ECM) adjusts the fuel delivery in order to control crankshaft speed at idle. If the ECM detects the engine speed is incorrect for the amount of fuel that is delivered, DTC P0506 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0506 Idle Speed Low
Conditions for Running the DTC
| • | DTCs P0016, P0117, P0118, P0335, P0336, P0340, P0341, P0500, or P0700 are not set. |
| • | The engine is running at idle for more than 10 seconds. |
| • | The idle is stable to within 20 RPM. |
| • | The fuel delivery is less than 2.5 mm³ per cylinder of target quantity. |
| • | The engine coolant temperature (ECT) is more than 50°C (122°F). |
| • | The intake air temperature (IAT) is less than 20°C (68°F). |
| • | The vehicle speed is 0 mph. |
| • | The throttle angle is 0 percent. |
| • | DTC P0506 runs continuously in a 250 ms test loop. |
Conditions for Setting the DTC
The actual idle speed is more than 100 RPM under the target idle speed.
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. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 | Are any other DTCs set? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information |
