PACCAR MX (2004 Emissions) Fault Code: P1566 Idle Speed Control – Incorrect

PACCAR MX (2004 Emissions) Fault Code: P1566 Idle Speed Control – Incorrect

SET CONDITIONS:
The PCI ECU (D420) detects that the actual fuel quantity during idling:
1. Differs on average more than 40 mg/stroke for more than 5 seconds from the requested fuel quantity, four times consecutively or
2. Is above 75 mg/stroke for more than 24 seconds or
3. Is below 8 mg/stroke for more than 24 seconds

DIAGNOSTIC CONDITION:
The diagnostic runs when the engine operating state is Idle.

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

POSSIBLE CAUSES:
1. Heavy load on engine during idling
2. fuel system failure
3. External fuel supply source

ADDITIONAL INFORMATION:
The idle speed governor function in the PCI ECU controls the idle speed. This diagnostic monitors that the actual fuel quantity during idling does not deviate too much from the requested fuel quantity during idling.