Diagnostics Item 18

DIAGNOSTIC ITEM 18: Diagnose when the scan tool cannot receive the data sent by occupant classification-ECU.

CAUTION:
When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do so, a component connected to the CAN bus line may be damaged.


















FUNCTION

If the scan tool MB991958 cannot communicate with the occupant classification-ECU, this diagnosis result will be set.

TROUBLE JUDGMENT CONDITIONS

If a communication flag is not set for the occupant classification-ECU, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS

- Malfunction of the connector [joint connector (CAN1), occupant classification-ECU connector improperly connected]
- Malfunction of the wiring harness [open circuit between the occupant classification-ECU connector and the joint connector (CAN1), power supply circuit to the occupant classification-ECU]
- Malfunction of the occupant classification-ECU

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check joint connector (CAN1) C-105, occupant classification-ECU connector D-39, D-39-2 and intermediate connector C-23 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

CAUTION:
The strand end of the twisted wire should be within 10 cm (4 inches) from the connector. For details refer to Precautions When CAN Bus Line(s) are Repaired.

Q. Are joint connector (CAN1) C-105, occupant classification-ECU connector D-39, D-39-2 and intermediate connector C-23 in good condition?

YES Go to Step 2.
NO Repair the damaged parts.
STEP 2. Check the wiring harness between joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2 for open circuit.

CAUTION:
Strictly observe the specified wiring harness repair procedure.
For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2, and check the wiring harness.





(2)Check the wiring harness between joint connector (CAN1) C-105 (terminal 3) and occupant classification-ECU connector D-39-2 (terminal 24)
OK: Continuity exists (2ohms or less)






(3)Check the wiring harness between joint connector (CAN1) C-105 (terminal 14) and occupant classification-ECU connector D-39-2 (terminal 25)
OK: Continuity exists (2ohms or less)

Q. Is the wiring harness between joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2 in good condition?

YES Check the power supply circuit of the occupant classification-ECU. Symptom Chart.

NO Repair the wiring harness between joint connector (CAN1) C-105 and occupant classification-ECU connector D-39-2.