[Previous][Next]
Diagnostic Item 7: Diagnose when the scan tool (M.U.T.-IIISE) cannot receive the data sent by steering wheel sensor.
 
 
cautionWhen servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do, a component connected to the CAN bus line may be broken.
 
 
FUNCTION
The diagnostic result demonstrates that "the scan tool (M.U.T.-IIISE) cannot receive the sent data from the steering wheel sensor" when the scan tool (M.U.T.-IIISE) checks the periodically sent data from each ECU and cannot receive the steering wheel sensor data only.
 
 
TROUBLE JUDGMENT CONDITIONS
The scan tool (M.U.T.-IIISE) judges the trouble when the periodically sent data from steering wheel sensor cannot be received.
 
 
TROUBLESHOOTING HINTS
  • Damaged harness wires and connectors
  • Power supply circuit malfunction of the steering wheel sensor
  • Malfunction of the steering column switch (steering wheel sensor)
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Connector check: joint connector (CAN1) and column switch connector
cautionThe strand end of the twist wire should be within 10 cm (3.9 inches) from the connector. For details refer to .
When checking the joint connector, ensure that its wiring harness side and its short pins are not damaged.
Is the check result normal?
Go to Step 2.
Repair the defective connector. Replace the joint connector as necessary.
 
STEP 2. Resistance measurement at joint connector (CAN1) and column switch connector.
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1) and the column switch connector, and measure at the wiring harness side.
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(4) Continuity between joint connector (CAN1) terminal No.10 and column switch connector terminal No.13
OK: The resistance should be 2 ohms or less
(5) Continuity between joint connector (CAN1) terminal No.21 and column switch connector terminal No.14
OK: The resistance should be 2 ohms or less
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<All the resistance measure 2 ohms or less> Go to Step 3.
<Either or all of the resistances measure more than 2 ohms> Repair the wiring harness between joint connector (CAN1) and the column switch connector.
 
STEP 3. Resistance measurement at column switch connector.
cautionA digital multimeter should be used. For details refer to .
(1) Remove the column switch, and measure at the equipment side.
(2) Resistance between column switch connector terminal Nos.13 and 14
OK: 1 kΩ or more
Is the check result normal?
Power supply to the steering wheel sensor may be suspected. Diagnose the steering wheel sensor. Refer to GROUP 35C - Troubleshooting .
Replace the steering column switch (steering wheel sensor).