Diagnostic Item 7

DIAGNOSTIC ITEM 7: Diagnose when the scan tool cannot receive the data sent by AWC-ECU. [RALLIART]

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.

CAN-C Communication Circuit (Part 1):

CAN-C Communication Circuit (Part 2):

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

TROUBLE JUDGEMENT CONDITIONS
If a communication flag is not set for the AWC-ECU, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS
- Malfunction of the connector [joint connector (CAN2) or AWC-ECU connector improperly connected]
- Malfunction of the wiring harness [open circuit between the AWC-ECU and the joint connector (CAN2), power supply circuit to the AWC-ECU]
- Malfunction of the AWC-ECU

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check joint connector (CAN2) C-05 and AWC-ECU connector C-51 and intermediate connector C-35 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.

Q: Are joint connector (CAN2) C-05 and AWC-ECU connector C-51 and intermediate connector C-35 in good condition?

YES : Go to Step 2.

NO : Repair the damaged parts.

STEP 2. Check the wiring harness between joint connector (CAN2) C-05 and AWC-ECU connector C-51 for open circuit.

CAUTION: Strictly observe the specified wiring harness repair procedure.

1. Disconnect joint connector (CAN2) C-05 and AWC-ECU connector C-51, and check the wiring harness.







2. Check the wiring harness between joint connector (CAN2) C-05 (terminal 4) and AWC-ECU connector C-51 (terminal 4)

OK: Continuity exists (2 ohms or less)







3. Check the wiring harness between joint connector (CAN2) C-05 (terminal 15) and AWC-ECU connector C-51 (terminal 5)

OK: Continuity exists (2 ohms or less)

Q: Is the wiring harness between joint connector (CAN2) C-05 and AWC-ECU connector C-51 in good condition?

YES : Check the power supply circuit of the AWC-ECU. Refer to Troubleshooting. Symptom Chart

NO : Repair the wiring harness between joint connector (CAN2) C-05 and AWC-ECU connector C-51.