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.

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. For details refer to

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

	Go to Step 2.

	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. For details refer to

(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 Ω 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 Ω or less)

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

Check the power supply circuit of the AWC-ECU. Refer to GROUP 22C, Troubleshooting

<ACD>.

Repair the wiring harness between joint connector (CAN2) C-05 and AWC-ECU connector C-51.