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
Trailer module (TRM) has the task of managing the electrical connections between the vehicle and trailer.
The main task of the control module is to manage output signals to the cable harness for the tow hitch for:
- Turn signal lamps
- Brake light
- Parking lamps
- Back-up lamp
- Fog lamps
- Charging (+12 V voltage).
The Trailer module (TRM) also communicates via the CAN network with:
- Central electronic module (CEM)
- Driver information module (DIM)
- Differential Electronic Module (DEM) (option)
- Parking Assistance Camera (PAC) (option)
- the Parking Assistance Module (PAM) (option).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no 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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.