When the TP sensor’s signal indicates closed throttle position and the engine is idling, the ECM adjusts the idle speed control actuator so that the engine runs at the correct idling speed, regardless of coolant temperature, load and etc. When the additional load applied in the engine, the air flow through the idle speed control actuator is increased momentarily to raise the idling speed.
The ECM monitors engine speed deviation from the target idle engine speed when the vehicle is stopped and the idle speed valve opening is stable. The ECM sets DTC P0506 if the difference to the target idle engine speed is lower than the predetermined threshold.
ITEM | DETECTING CONDITION | POSSIBLE CAUSE |
DTC Strategy | ● Compare engine speed and nominal idle speed in idle state | ● Restriction in intake or exhaust system ● Carbonustment of the accelerator cable ● Contact resistance in connectors ● Faulty ICA valve |
Enable Conditions | ● Vehicle speed =0 ● Coolant temperature〉75℃(167℉) ● Engine load 〈840 mg/rev. ● Throttle angle:closed ● Minimum time after start:10sec. ● Canister purge control 〈 70% | |
Threshold Value | ● Target idle speed - Engine speed 〉 100rpm (Engine speed too low) | |
Diagnostic Time | ● 18.5 sec. | |
Fail Safe | ● Evaporative System monitoring is inhibited |
