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.
Differential Electronic Module (DEM) and Active On-Demand Coupling
The main role of active on-demand coupling and the differential electronic module (DEM) is to regulate the all wheel drive (AWD) function by distributing torque between the front and rear axles. The system consists of a coupling that combines mechanical, hydraulic and electronic sections. The coupling unit is attached to the rear axle, between the differential gear and the driveshaft. The mechanical and hydraulic sections are driven by the driveshaft. Active on-demand coupling (AOC) has the following characteristics:
- Permanent AWD with electronic control of torque transfer front to rear
- Similar to four wheel drive (4WD) operation
- No driveline wind-up during slow speed maneuvers or parking
The system is not sensitive to size differences between the 4 road tires (when driving with a spare wheel, for example). The system is not sensitive to being towed with one axle raised.
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.