Diagnostics Item 14

DIAGNOSTIC ITEM 14: Diagnose the lines between joint connector (CAN3) and joint connector (CAN4). [TC-SST]

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 a failure is present in the wiring harness between the joint connector (CAN3) and the joint connector (CAN4), this diagnosis result will be set.

TROUBLE JUDGMENT CONDITIONS

If a communication flag is not set for some of the ECUs on the CAN-C line, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS

- Malfunction of the connector [joint connector (CAN3), joint connector (CAN4) or intermediate connector failed]
- Malfunction of the wiring harness [open circuit between joint connector (CAN3) and joint connector (CAN4)]

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check joint connector (CAN3) C-127, joint connector (CAN4) A-14 and intermediate connector A-13 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 (CAN3) C-127, joint connector (CAN4) A-14 and intermediate connector A-13 in good condition?

YES Go to Step 2.
NO Repair the damaged parts.
STEP 2. Check the wiring harness between joint connector (CAN3) C-127 and joint connector (CAN4) A-14 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 (CAN3) C-127 and joint connector (CAN4) A-14, and check the wiring harness.





(2)Check the wiring harness between joint connector (CAN3) C-127 (terminal 3) and joint connector (CAN4) A-14 (terminal 5)
OK: Continuity exists (2ohms or less)






(3)Check the wiring harness between joint connector (CAN3) C-127 (terminal 14) and joint connector (CAN4) A-14 (terminal 16)
OK: Continuity exists (2ohms or less)

Q. Is the wiring harness between joint connector (CAN3) C-127 and joint connector (CAN4) A-14 in good condition?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).

NO Repair the wiring harness between joint connector (CAN3) C-127 and joint connector (CAN4) A-14.