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.
Serial Communicating Circuit Inspection
- Check short in serial communication line
- "IG KEY OFF".
- Disconnect SMK unit connector and ECM connector.
- Measure resistance between serial communication signal terminal of ECM harness connector and chassis ground.
Specification: Infinite (∞)
For wiring diagram information, refer to the ETM .
- Is the measured resistance within specification?
YES
- Go to open in harness as follow.
NO
- Check short to ground in harness. And then, repair or replace as necessary. Finally, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Check open in harness
- IG KEY OFF.
- Disconnect Smartkey Module connector and ECM connector.
- Measure resistance between signal terminal of SMK Unit harness connector and signal terminal of ECM harness connector.
Specification: About below 1Ω
For wiring diagram information, refer to the ETM .
- Is the measured resistance within specification?
YES
- Check poor connection between harness connector and SMK unit or ECM/PCM:
Thoroughly check the looseness, poor connection, bent, corrosion, contamination, deformation or damage of connector. Repair or replace as necessary and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- If the system is repaired by replacing the Smart Key Unit (PIC IMMO Unit), ECM/PCM, replace the unit.
- Repair or replace as necessary and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- After replacing SMK unit, perform Key teaching procedure with GDS.
NO
- Check open in signal harness. And, repair or replace as necessary then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Check poor connection between harness connector and SMK unit or ECM/PCM:
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.