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.
Checking The Components And Wiring
Check the signal cable between the central electronic module (CEM) and the rear windshield heating. Check for an open-circuit. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) terminal #C28 (#28) and rear windshield heating connector.
Checking the rear windshield
Measure the resistance in the heating loop.
Normal resistance at +20°C for:
- 4-doors, approximately 0.63 Ω.
- 5-doors, approximately 0.76 Ω.
Remedy as necessary.
Other information
- see CONNECTING THE BREAKOUT BOX
- see SIGNAL DESCRIPTION CENTRAL ELECTRONIC MODULE (CEM)
- see CONTROL MODULE RELAY BOX PASSENGER COMPARTMENT
- see CHECKING WIRING AND TERMINALS
- Continue
Refer to REPLACING THE COMPONENT
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.