Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to "CAN Communication Line Inspection" procedure.

The CAN bus must be disconnected from the power supply

The measurement is taken between the CAN High and CAN Low leads

The measurement recorded may differ from the specified levels by a few ohms

Ignition "OFF" and disconnect the battery and wait about four minutes.

Make sure all modules are properly connected.

Measure resistance between Pin No. 3 (C-CAN High) and Pin No. 11 (C-CAN Low) terminal of Data Link Connector(DLC).

Is measured value within specification?

	▶ Check each module connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
	▶ If the measured value is out of specification, go to "CAN resistor inspection" procedure. ※ If the measured value is approx. 0Ω, then check for short CAN communication line. ※ If the measured value is approx. 120Ω, then check for open CAN commuication line of control module with resistor.

Ignition OFF.

Disconnect Battery (-) terminal.

Disconnect IC and BCM connectors.

Measure resistance between Pin No. 8(C-CAN Low) and Pin No. 9(C-CAN High) terminal of BCM.

Measure resistance between Pin No. 66(C-CAN Low) and Pin No. 87(C-CAN High) terminal of ECM/PCM.

Is measured value within specification?

	▶ Go to "Short in CAN Communication Line Inspection" procedure.
	▶ If problem still occurs, replace module has defected resistor and then go to "Verification of Vechicle Repair" procedure.

Ignition "ON"

Measure voltage between Pin No. 3 (C-CAN High) terminal of Data Link Connector(DLC) and chassis ground.

Measure voltage between Pin No. 11 (C-CAN Low) terminal of Data Link Connector(DLC) and chassis ground.

Is measured value within specification?

	▶ Go to "Component Inspection" procedure.
	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

Refer to "Shop Manual" and remove necessary parts to get access to BCM, ECM, TCM, HECU and other control units that connected to C-CAN Communication circuit.

Connect GDS to Data Link Connector(DLC).

Ignition "ON"

Disconnect unit connector one after the other.

Check for control unit causing the fault by communicating BCM, ECM, TCM, HECU and others with GDS.

Does GDS able to communicate with any of systems when one unit connector is disconnected?

	▶ If problem still occurs, replace FATC that casuing the fault and then go to "Verification of Vechicle Repair" procedure.
	▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of vehicle Repair" procedure.