Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

Service check mode (Navigation ECU) (See PRE-CHECK ).
1. CHECK: Troubleshoot for each diagnosis.
2. OK : Replace multi display (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
3. NCON: Go to next step.
Check navigation ECU.
PREPARATION:

Disconnect the navigation ECU connector.

CHECK:

Check the voltage of terminal +B.

OK:

+B: 10 - 14 V

CHECK:

Check the voltage of terminal ACC when the ignition switch is in ACC or ON position.

OK:

ACC: 10 - 14 V

CHECK:

Check continuity at terminal GND.

OK:

GND: Continuity
1. NG : Replace or repair wire harness (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Go to next step.
Check navigation ECU.
CHECK:

Check terminal R, G and B.

OK:

R, G, B: See "Navigation ECU" of "TERMINAL OF ECU".
1. NG : Replace navigation ECU (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Go to next step.
Check multi display.
PREPARATION:

Disconnect the multi display connector.

CHECK:

Check the voltage of terminal +B.

OK:

+B: 10 - 14 V

CHECK:

Check the voltage of terminal ACC when the ignition switch is in ACC or ON position.

OK:

ACC: 10 - 14 V

CHECK:

Check continuity at terminal GND.

OK:

GND: Continuity

CHECK:

Check terminal R, G and B.

OK:

R, G, B: See "multi display" of "TERMINAL OF ECU"
1. NG : Replace or repair wire harness or connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Go to next step.
Check "AVC-LAN communication circuit" (See AVC-LAN (COMMUNICATION BUS) CIRCUIT ).
CHECK:

Check continuity of the wire harness between the multi display and the navigation ECU.

OK:

Continuity
1. NG : Replace or repair AVC-LAN circuit (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Replace multi display (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).