Inspection Procedure

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

Check And Operate Again
1. Turn the ignition switch from OFF to ON, the check that the malfunction disappear.
  Standard: Malfunction disappear
NOTE: Even if the works correctly, the following conditions may be seen, vehicle position mark turns, or the map turns unwillingly. (It is because by turning the IG switch to ACC or ON during turning, navigation system stores based on the angular speed). In that case, turn the IG switch from OFF to ACC or ON to return the correct function.
1. OK: Normal (Recheck The Operation)
2. NG: Go To Next Step
Navigation Check Mode (Vehicle Sensors)
1. Perform vehicle signal check of navigation check mode.
  1. Start up the diagnosis system and read of "SPD" signal in vehicle sensors mode.
  Standard: Input signal is normal
1. OK: Check And Replace Navigation ECU
2. NG: Go To Next Step
Inspect Navigation ECU (SPD, GND)
1. Remove the navigation ECU with connectors still connected.
2. Check voltage.
  1. Shift the shift lever to neutral.
  2. Jack up one of the front wheels.
  3. Turn ignition switch ON.
  4. Measure voltage between terminals SPD and GND of navigation ECU when the front wheel are turned slowly.
    
    Fig 1: Inspecting Navigation ECU Terminals
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  Voltage is generated intermittently.
  
  Fig 2: Identifying Waveform Of SPD And GND Terminal
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Check And Replace Navigation ECU
2. NG: Repair Or Replace Harness Or Connector