Many malfunctions in the electrical system are caused by poor harness and terminals.

Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

Thoroughly check all connectors(and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.

Has a problem been found?

	▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
	▶ Go to "CAN Communication line check" procedure.

Ignition "OFF".

Disconnect BSD ECU(LH) connector and ECM(EMS) connector.

Measure resistance between Pin No. 7(C-CAN-HIGH) of the BSD ECU(LH) connector and Pin No. 57(C-CAN-HIGH) of the ECM connector.(1.6MPI Only)

Measure resistance between Pin No. 7(C-CAN-HIGH) of the BSD ECU(LH) connector and Pin No. 85(C-CAN-HIGH) of the ECM connector.(1.0T-GDI, 1.6GDI, 1.6T-GDI Only)

Measure resistance between Pin No. 7(C-CAN-HIGH) of the BSD ECU(LH) connector and Pin No. 64(C-CAN-HIGH) of the ECM connector.(1.4U-II, 1.6U-II Only)

Measure resistance between Pin No. 7(C-CAN-HIGH) of the BSD ECU(LH) connector and Pin No. 41(C-CAN-HIGH) of the ECM connector.(1.4MPI Only)

Measure resistance between Pin No. 3(C-CAN-LOW) of the BSD ECU(LH) connector and Pin No. 79(C-CAN-LOW) of the ECM connector.(1.6MPI Only)

Measure resistance between Pin No. 3(C-CAN-LOW) of the BSD ECU(LH) connector and Pin No. 63(C-CAN-LOW) of the ECM connector.(1.0T-GDI, 1.6GDI, 1.6T-GDI Only)

Measure resistance between Pin No. 3(C-CAN-LOW) of the BSD ECU(LH) connector and Pin No. 81(C-CAN-LOW) of the ECM connector.(1.4U-II, 1.6U-II Only)

Measure resistance between Pin No. 3(C-CAN-LOW) of the BSD ECU(LH) connector and Pin No. 29(C-CAN-LOW) of the ECM connector.(1.4MPI Only)

Is the measured resistance within specification?

	▶ Go to "Component Inspection" procedure.
	▶ Check for open & short in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.