Lexus IS250 · Service Manual STEERING

DIAGNOSIS SYSTEM

Troubleshooting


DESCRIPTION

  1. When troubleshooting a vehicle with the diagnostic system, the only difference from the usual troubleshooting procedure is connecting the intelligent tester to the vehicle and reading various data output from the vehicle's multiplex tilt & telescopic ECU.
    The multiplex tilt & telescopic ECU records DTCs when the ECU detects a malfunction in the computer itself or in its circuits.
    To check the DTCs, connect the intelligent tester to the DLC3 on the vehicle. The intelligent tester enables you to erase the DTCs, activate several actuators, and check the freeze frame data and various forms of steering data.


DLC3 CHECK

  1. A082779E02
    Check the DLC3.

    1. The multiplex tilt & telescopic ECU uses CAN and ISO 15765-04 for its communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-03 and matches the ISO 15765-04 format.

      Symbols (Terminal No.)
      		 Terminal Description
      		 Condition
      		 Specified Condition
      SIL (7) - SG (5)
      		 Bus "+" line
      		 During communication
      		 Pulse generation
      CG (4) - Body ground
      		 Chassis ground
      		 Always
      		 Below 1 Ω
      SG (5) - Body ground
      		 Signal ground
      		 Always
      		 Below 1 Ω
      BAT (16) - Body ground
      		 Battery positive
      		 Always
      		 11 to 14 V
      CANH (6) - CANL (14)
      		 HIGH-level CAN bus line
      		 Engine switch off
      		 54 to 67 Ω
      CANH (6) - Battery positive
      		 HIGH-level CAN bus line
      		 Engine switch off
      		 1 MΩ or higher
      CANH (6) - CG (4)
      		 HIGH-level CAN bus line
      		 Engine switch off
      		 3 kΩ or higher
      CANL (14) - Battery positive
      		 LOW-level CAN bus line
      		 Engine switch off
      		 1 MΩ or higher
      CANL (14) - CG (4)
      		 LOW-level CAN bus line
      		 Engine switch off
      		 3 kΩ or higher

      HINT:
      If the display shows a communication error message after connecting the intelligent testercable to the DLC3 and turning the engine switch on (IG), there is a problem either with the vehicle or the tester.
      1. If communication is normal when connecting the tester to another vehicle, inspect the DLC3 on the original vehicle.
      2. If communication is still not possible when connecting the tester to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's operator's manual.

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