[Previous][Next]
DIAGNOSTIC ITEM 23: Diagnose when the scan tool cannot receive the data sent by WCM <vehicles without KOS>.
 
 
cautionWhen 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 WCM, this diagnosis result will be set.
 
 
TROUBLE JUDGMENT CONDITIONS
If a communication flag is not set for the WCM, the ETACS-ECU determines that there is a failure.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the connector [joint connector (CAN1) or WCM connector improperly connected]
  • Malfunction of the wiring harness [open circuit between the WCM connector and the joint connector (CAN1), power supply circuit to the WCM]
  • Malfunction of the WCM
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check joint connector (CAN1) C-05 and WCM connector C-09 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
cautionThe strand end of the twisted wire should be within 10 cm (4 inches) from the connector. For details refer to .
Are joint connector (CAN1) C-05 and WCM connector C-09 in good condition?
Go to Step 2.
Repair the damaged parts.
 
STEP 2. Check the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and WCM connector C-09, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.9) and WCM connector C-09 (terminal No.3)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.20) and WCM connector C-09 (terminal No.2)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 in good condition?
Check the power supply circuit of the WCM. Refer to GROUP 42C, Diagnosis .
Repair the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09.