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DIAGNOSTIC ITEM 10: Diagnose when the scan tool cannot receive the data sent by electric power steering-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 electric power steering-ECU, this diagnosis result will be set.
 
 
TROUBLE JUDGMENT CONDITIONS
If a communication flag is not set for the electric power steering-ECU, the ETACS-ECU determines that there is a failure.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the connector [joint connector (CAN3), electric power steering-ECU connector improperly connected]
  • Malfunction of the wiring harness [open circuit between the electric power steering-ECU connector and the joint connector (CAN3), power supply circuit to the electric power steering-ECU]
  • Malfunction of the electric power steering-ECU
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check joint connector (CAN3) C-24 and electric power steering-ECU connector C-144, intermediate connector C-146 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 (CAN3) C-24 and electric power steering-ECU connector C-144, intermediate connector C-146 in good condition?
Go to Step 2.
Repair the damaged parts.
 
STEP 2. Check the wiring harness between joint connector (CAN3) C-24 and electric power steering-ECU connector C-144 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN3) C-24 and electric power steering-ECU C-144, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN3) C-24 (terminal 9) and electric power steering-ECU C-144 (terminal 5)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN3) C-24 (terminal 20) and electric power steering-ECU C-144 (terminal 6)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN3) C-24 and electric power steering-ECU connector C-144 in good condition?
Check the power supply circuit of the electric power steering-ECU. Refer to GROUP 37, Power steering diagnosis .
Repair the wiring harness between joint connector (CAN3) C-24 and electric power steering-ECU C-144.