Inspection Procedure

1. Remove the navigation ECU with connectors with still connected.
2. Check voltage.
   1. Measure voltage between terminals +B, ACC and GND of navigation ECU at each conditions, as shown in the chart.
   Fig 1: Inspecting Navigation ECU (+B, ACC, GND)

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   Fig 2: STANDARD

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3. Check continuity.

1. Check that the continuity exists between terminal GND of navigation ECU and body ground.

Standard: Continuity exists. 

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go To Next Step 

1. Check continuity.
   1. Check that the continuity exists between each terminals, as shown in the chart.
   Fig 3: Inspecting Navigation ECU (Sync, Vr, Vg)

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   Fig 4: STANDARD

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2. Check signal waveform.

1. Using an oscilloscope, check signal waveform between terminals SYNC and GND of navigation ECU

HINT:

Signal wave from is shown in the chart.

Fig 5: Checking Signal Waveform

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NG: CHECK AND REPLACE RADIO RECEIVER ASSY 

OK: Go To Next Step 

1. Check continuity.
   1. Check that the continuity exists between each terminals, as shown in the chart.
   Fig 6: Identifying Terminals Condition And Voltage Specification Table

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   Fig 7: STANDARD

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2. Check signal waveform.

1. Using an oscilloscope, check signal waveform between terminals SYNC and GND of radio receiver assy.

Fig 8: Identifying Signal Waveform

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HINT:

Signal wave from is shown in the chart.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: CHECK AND REPLACE RADIO RECEIVER ASSY