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DIAGNOSTIC ITEM 11: Diagnose when the scan tool cannot receive the data sent by SRS-ECU.
 
 
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 SRS-ECU, this diagnosis result will be set.
 
 
TROUBLE JUDGMENT CONDITIONS
If a communication flag is not set for the SRS-ECU, the ETACS-ECU determines that there is a failure.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the connector [joint connector (CAN2) or SRS-ECU connector improperly connected]
  • Malfunction of the wiring harness [open circuit between the SRS-ECU connector and the joint connector (CAN2), power supply circuit to the SRS-ECU]
  • Malfunction of the SRS-ECU
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check joint connector (CAN2) C-202 and SRS-ECU connector C-126 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 (CAN2) C-202 and SRS-ECU connector C-126 in good condition?
Go to Step 2.
Repair the damaged parts.
 
STEP 2. Check the wiring harness between joint connector (CAN2) C-202 and SRS-ECU connector C-126 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN2) C-202 and SRS-ECU connector C-126, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN2) C-202 (terminal No.3) and SRS-ECU connector C-126 (terminal No.30)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN2) C-202 (terminal No.14) and SRS-ECU connector C-126 (terminal No.29)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN2) C-202 and SRS-ECU connector C-126 in good condition?
Check the power supply circuit of the SRS-ECU. Refer to GROUP 52B, SRS Air Bag Diagnosis .
Repair the wiring harness between joint connector (CAN2) C-202 and SRS-ECU connector C-126.