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.
CAN communication Circuit Inspection
- Connect all unit/module's connector.
- IG key "ON", Engine "OFF".
- Measure the voltage between "B-CAN High" terminal of DDM* harness connector and chassis ground.
- Measure the voltage between "B-CAN Low" terminal of DDM* harness connector and chassis ground.
Specification: Below 5V(1.5V~3.5V)
- Is the measured value within specifications?
YES
- Disconnect B-CAN communication unit/module one by one and monitor DTC to find the cause.
→ If the DTC erase, substitute with a known-good unit/module and check for proper operation.
→ If the problem is corrected, replace the unit/module.
- Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- If the measured value is the battery voltage level(12V),
→ Repair short between the harness and the battery power.
- If the measured value is the ground level(0V), → Repair short between "B-CAN High" line and "B-CAN Low" line.
→ Repair open/poor connection in the harness.
→ Repair short between the harness and the chassis ground.
- Disconnect B-CAN communication unit/module one by one and monitor DTC to find the cause.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.