Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Control Module Communications
The control module system has a computer, the engine control module (ECM), to control fuel delivery, timing, and some emission control systems. The control module system monitors a number of engine and vehicle functions and controls the following operations through the fuel injection control module (FICM):
- Fuel rail pressure
- Fuel injector
- Fuel injector pulse width
The diesel engine control module (ECM), located in the engine compartment, is the control center of the control module system. The engine control module used on the electronic fuel injected 6.6L diesel is referred to as a ECM.
The ECM constantly looks at the information from various sensors, and controls the systems that affect vehicle performance. The ECM performs the diagnostic function of the system. The ECM can recognize operational problems, alert the driver through the MIL - Service Engine Soon, and store one or more diagnostic trouble codes (DTCs) which identify the problem areas to aid the technician in making repairs. See the specific diagnosis procedure for more information.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.