Navigation ECU Power Source Circuit: Procedure
- INSPECT FUSE (RADIO NO. 2, AM1, TV)
- Remove the RADIO NO. 2 and TV fuses from the passenger side junction block.
- Remove the AM1 fuse from the driver side junction block.
- Measure the resistance of the fuses.
Standard resistance
Below 1 Ω
NG → REPLACE FUSE
OK: Go to next step
- INSPECT RELAY (Marking: ACC)
- Remove the ACC relay from the passenger side junction block.
- Measure the resistance of the relay.
Standard resistance
Tester Connection Specified Condition 3 - 5 Below 1 Ω 3 - 5 10 kΩ or higher
(when battery voltage is applied to terminals 1 and 2)
NG → REPLACE RELAY
OK: Go to next step
- CHECK WIRE HARNESS (NAVIGATION ECU - BATTERY AND BODY GROUND)
- Disconnect the N3 and N7 ECU connectors.
- Measure the resistance and voltage of the wire harness side connectors.
Standard resistance
Standard voltage
Tester Connection Specified Condition N3-17 (GND1) - Body ground Below 1 Ω N7-7 (SNSE) - Body ground Below 1 Ω Tester Connection Condition Specified Condition N3-18 (ACC) - Body ground Ignition switch ACC 10 to 14 V N3-9 (+B) - Body ground Always 10 to 14 V
NG → REPAIR OR REPLACE HARNESS AND CONNECTOR
OK → PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE OR DIAGNOSTIC TROUBLE CODE CHART