Diagnostic Item 20

DIAGNOSTIC ITEM 20: Diagnose When The Scan Tool Cannot Receive The Data Sent By Radio And CD Player Or CD Changer.

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-B Communication Circuit (Part 1):

CAN-B Communication Circuit (Part 2):

FUNCTION
If the scan tool MB991958 cannot communicate with the radio and CD player or CD changer, this diagnosis result will be set.

TROUBLE JUDGEMENT CONDITIONS
If a communication flag is not set for the radio and CD player or CD changer, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS
- Malfunction of the connector [joint connector (CAN1), radio and CD player or CD changer connector improperly connected]
- Malfunction of the wiring harness [open circuit between the radio and CD player or CD changer connector and the joint connector (CAN1), power supply circuit to the radio and CD player or CD changer]
- Malfunction of the radio and CD player or CD changer

DIAGNOSIS

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

STEP 1. Check joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107 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 (CAN1) C-105 and radio and CD player or CD changer connector C-107 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 radio and CD player or CD changer connector C-107 for open circuit.

CAUTION: Strictly observe the specified wiring harness repair procedure.

1. Disconnect joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107, and check the wiring harness.




2. Check the wiring harness between joint connector (CAN1) C-105 (terminal 5) and radio and CD player or CD changer connector C-107 (terminal 23)

OK: Continuity exists (2 ohms or less)




3. Check the wiring harness between joint connector (CAN1) C-105 (terminal 16) and radio and CD player or CD changer connector C-107 (terminal 33)

OK: Continuity exists (2 ohms or less)

Q : Is the wiring harness between joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107 in good condition?

YES : Check the power supply circuit of the radio and CD player or CD changer. Refer to radio and CD player Diagnosis [radio and CD player]. Trouble Symptom Chart

NO : Repair the wiring harness between joint connector (CAN1) C-105 and radio and CD player or CD changer connector C-107.