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.
Combustion PREHEATER Module (CPM) (2008-2012): Design: Heater
The heater has the following internal electrical components:
- control module
- combustion air fan motor
- glow plug
- coolant temperature sensor
- overheating sensor
- fuel preheater (diesel only)
External electrical components:
- Coolant pump
- fuel pump
- remote start device (accessory)
There are 6 connectors above the control module. 3 of these are accessible from outside and are for connection to the vehicle, coolant pump and fuel pump. The other 3 are under a plastic cover and are for internal electrical components. The fan motor is directly connected to the control module circuit board with 2 pins.
Use the Manual With the Right Hardware
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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.