0281011134 | Genuine GM® Fuel Injection Control Module 6.6L 2004-2005

• Controls Injector Timing:
  It determines the exact moment each injector should fire so fuel is delivered at the optimal point in the engine’s cycle.

• Controls Injector Duration (Pulse Width):
  It regulates how long each injector stays open, which controls how much fuel enters each cylinder.

• Boosts Electrical Power to Injectors:
  Diesel injectors (especially high-pressure ones) require high voltage—often around 48 volts—to open and close properly. The FICM generates and sends this voltage to the injectors.

• Communicates with the ECU:
  The FICM receives input from sensors (e.g., engine speed, temperature, throttle position) via the ECU and adjusts fuel delivery accordingly.

Engine Performance Symptoms

Hard Starting or No Start
The engine cranks but takes a long time to fire, or doesn’t start at all.
Often worse when the engine is cold.
Rough Idle or Misfire
The engine may idle roughly or misfire intermittently.
You might feel shaking or uneven running at low RPMs.
Loss of Power
Noticeable drop in power during acceleration or towing.
Poor throttle response.
Stalling
Engine may randomly die when idling or under light load.

Electrical or Control Symptoms

Low FICM Voltage
The FICM should supply 48 volts (on most PowerStroke engines).
If voltage drops below ~45 volts, injector performance suffers.
Check Engine Light / Trouble Codes
Common diagnostic trouble codes (DTCs):
P0611 – FICM performance fault
P1378, P1379 – FICM voltage issues
Injector circuit codes (P0261–P0286 range)

Exhaust and Fuel Symptoms

White or Gray Smoke
Unburned fuel due to injectors not firing correctly.
White smoke especially noticeable at startup.
Poor Fuel Economy
Because of inefficient injection timing and incomplete combustion.