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.
Troubleshooting - B-CAN System Diagnosis Test Mode C
Do this diagnosis if a component that is controlled by the B-CAN system does not stop or turn off.
- If the component does not run or turn on, go to B-CAN System Diagnosis Test Mode D (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE D ).
- See the B-CAN system unit input/output index for a list of input and output devices and the control units that monitor the input and control the output devices (see HDS INPUTS AND COMMANDS ).
- Check for DTCs by selecting the TEST MODE menu from the HDS.
Are any DTCs indicated?
YES -Go to B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
NO -Go to step 2.
- Turn off the switch that controls the malfunctioning component.
- Select DATA LIST from the TEST MODE menu, and check the input of the switch that controls the component.
Does the HDS indicate the switch is OFF?
YES -Go to step 4.
NO -Go to step 6.
- In the DATA LIST, check the output signal of the malfunctioning component.
Is the output signal OFF?
YES -Go to step 5.
NO -Replace the control unit that controls the device that will not turn OFF.
- Test the relay that controls the device that does not stop or turn off, if applicable. If the relay tests OK, then check for a short in the wire between the relay and the component, the relay and control unit, or the component and control unit.
Are the relay and the wire harness OK?
YES -Replace the control unit that controls the component that will not stop or turn OFF.
NO -Replace the relay or repair/replace the wire harness.
- Test the switch, then check for a short in the wire between the switch and the control unit that monitors the switch.
Are the switch and wire harness OK?
YES -Replace the control unit that monitors the switch.
NO -Replace the switch or repair/replace the wire harness.
NO RELATED
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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.