P1223 - Leak Detection Based On Quantity Balance

NOTE: For a complete wiring diagram, refer to the Wiring Information.

There is a required amount of fuel required by the fuel system to keep the system stable. The amount of fuel required depends on fuel pressure, injection quantity, engine speed,

and coolant temperature. The Engine Control Module (ECM) sets Leakage Detected, when the fuel flow exceeds an expected value. When a leak is detected in the system, a counter is initiated. When the counter reaches a predetermined value a fault is set and engine derate is enabled. When the leak is not detected the counter counts down, and once the counter becomes zero the engine is set back to normal running conditions.

**A solid Wait to Start lamp will illuminate in the cluster along with chiming 10 times. When the fault goes inactive, it will clear the wait to start lamp with no chimes**.

When Monitored:

Engine is running above low idle speed and at operating temperature with no fuel system and engine speed related DTC's.

• Set Condition: Counter reaches a calibrated value. Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Possible Causes

Excessive Injector Return

NOTE: Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

OTHER DTC's PRESENT

1. Turn the ignition on.

2. With the scan tool, select View DTC's. Are there any other fuel system related DTC's present along with this DTC?

a. Yes >>> Perform the diagnostics for the other fuel system DTC's before proceeding.

b. No >>>> Perform the INJECTOR RETURN FLOW TEST procedure.