Progressive Power Steering System - Diagnosis: Pre-Check

DESCRIPTION
1. DIAGNOSIS SYSTEM
  When troubleshooting is conducted for Multiplex OBD (M-OBD) vehicles, the only difference from the usual troubleshooting procedure is that the LEXUS hand-held tester is to be connected to read off various data output from the vehicle's skid control ECU.
  
  The skid control ECU records the corresponding DTC when the computer detects a malfunction in the computer itself or its circuit.
  
  To check DTC, connect a LEXUS hand-held tester to DLC3 on the vehicle. The LEXUS hand-held tester enables you to erase DTC and activate the several solenoids and actuators, and check freeze frame data and various forms on skid control data.
2. DATA LINK CONNECTOR 3 (DLC3)
  The skid control ECU uses ISO 14230 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 14230 format.
  
  Fig 1: Identifying DLC3 Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: DLC3 Terminals Description Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:

If the display shows "UNABLE TO CONNECT TO VEHICLE" when the LEXUS hand-held tester cable is connected to DLC3, the ignition switch is turned ON and the LEXUS hand-held tester is operated, there is a problem on the vehicle side or the tester side.
- If communication is normal when the tester is connected to another vehicle, inspect DLC3 on the original vehicle.
- If communication is still not possible when the tester is connected to another vehicle, the problem is probably the tester itself, so consult the Service Department listed in the tester's Operator's Manual.
DIAGNOSIS INSPECTION
1. Check the battery.
  1. Inspect the battery positive voltage.
    Battery positive voltage: 10 - 14 V
2. Check the DTC.
  1. Hook up the LEXUS hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. Read the DTC by following the prompts on the tester screen.
  HINT:
  
  Please refer to the LEXUS hand-held tester operator's manual for further details.
3. Clear the DTC.
  1. Hook up the LEXUS hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. Operate the LEXUS hand-held tester to erase the codes.
  HINT:
  
  Please refer to the LEXUS hand-held tester operator's manual for further details.
REFERENCE VALUE OF ECU DATA
1. Hook up the LEXUS hand-held tester to the DLC3.
2. Monitor the ECU data by following the prompts on the tester screen.
Please refer to the LEXUS hand-held tester operator's manual for more information.

Fig 3: ECU Data Reference Value Table
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002