DTC Advanced Diagnostics: P0506 (3.0L Engine)
DTC P0506: Idle Control System RPM Lower Than Expected
General Description
A target idle speed that meets the engine operating conditions (coolant temperature, A/C ON or OFF, etc.) is stored in the powertrain control module (PCM). The PCM monitors and controls the idle speed so that the actual idle speed is equal to the target idle speed. If the actual idle speed varies beyond a specified value from the target speed over a certain period of time, the PCM detects a malfunction in the idle speed control system and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 20 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | |
|---|---|
| Idle speed control | Closed loop |
| Quick warm-up | Off |
Malfunction Threshold
Actual idle speed - (minus) target idle speed is less than -100 rpm for at least 15 seconds.
Possible Cause
- Crankshaft position (CKP) sensor failure
- Fuel system failure
- Intake manifold air leak
- Intake air system air leak
- Ignition system failure
- Hardware failure
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
- Let the engine idle for at least 20 seconds.
[ ]: HDS Parameter
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.