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.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. This step checks whether the scan tool can communicate with other control modules on the vehicle. If the scan tool can communicate with the PCM then the DLC ground circuit (terminal 4) and the DLC ignition positive voltage circuit (terminal 16) are OK.
5. This step checks for an open in the serial data circuit between the BPMV and the right instrument panel junction block or for a defective BPMV.
6. This step checks for an open/shorted to ground circuit, a shorted to battery positive circuit, or for a defective scan tool.
7. The modules supply a low current (about 1.85 mA) on the serial data circuit. The normal circuit low current will NOT illuminate a test lamp. If the circuit is shorted to battery positive the higher current will illuminate the test lamp.
10. The scan tool may be damaged by high current flow on the serial data circuit at DLC terminal 7. Verify the scan tool for proper operation on a known good vehicle that uses terminal 7 of the DLC for serial data communication.
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.