Problem Symptoms Table

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

Before inspecting the suspected areas listed in the table below, check the fuse and relay.
Before inspecting the suspected areas listed in the table below, check the DTCs.
Methods used to verify the cause of the problem are listed in order of probability in the suspected area column.

Display function

SYMPTOM CHART

Symptom

Suspected area

Black screen (No image appears on navigation/audio screen).

1. "BLACK SCREEN (NO IMAGE APPEARS ON NAVIGATION AND AUDIO SCREEN) "

2. DIMMER SIGNAL CIRCUIT

3. MULTI-DISPLAY POWER SOURCE CIRCUIT

4. AVC-LAN CIRCUIT

5. Replace MULTI-DISPLAY

Illumination for panel switch does not come on with TAIL switch on.

1. "ILLUMINATION FOR PANEL SWITCH DOES NOT COME ON WITH TAIL SWITCH ON "

2. ILLUMINATION CIRCUIT

3. Replace MULTI-DISPLAY

Display does not dim (Night Screen) with TAIL switch on.

1. "DISPLAY DOES NOT DIM (NIGHT SCREEN) WITH TAIL SWITCH ON "

2. DIMMER SIGNAL CIRCUIT

3. Replace MULTI-DISPLAY

Power does not turn off (The screen remains on).

1. MULTI-DISPLAY POWER SOURCE CIRCUIT

2. Replace MULTI-DISPLAY

Panel switches do not function.

1. "PANEL SWITCHES DO NOT FUNCTION "

2. Steering pad switch circuit (audio function). See TAPE IS TANGLED DUE TO INCORRECT TAPE SPEED OR AUTO-REVERSE MALFUNCTION

3. STEERING PAD SWITCH CIRCUIT (NAVIGATION FUNCTION)

4. MULTI-DISPLAY POWER SOURCE CIRCUIT

5. Replace MULTI-DISPLAY

Touch panel switch does not function.

1. "TOUCH PANEL SWITCH DOES NOT FUNCTION "

2. Steering pad switch circuit (audio function). See TAPE IS TANGLED DUE TO INCORRECT TAPE SPEED OR AUTO-REVERSE MALFUNCTION

3. Steering pad switch circuit (navigation function)

4. MULTI-DISPLAY POWER SOURCE CIRCUIT

5. Replace MULTI-DISPLAY

Navigation screen is not displayed.

1. DISPLAY SIGNAL CIRCUIT BETWEEN NAVIGATION ECU AND MULTI-DISPLAY CONTROLLER (⁽¹⁾)

2. DISPLAY SIGNAL CIRCUIT BETWEEN NAVIGATION ECU AND TELEVISION CAMERA ECU (⁽²⁾)

3. DISPLAY SIGNAL CIRCUIT BETWEEN MULTI-DISPLAY CONTROLLER AND TELEVISION CAMERA ECU (⁽¹⁾)

4. DISPLAY SIGNAL CIRCUIT BETWEEN TELEVISION CAMERA ECU AND MULTI-DISPLAY

5. Replace MULTI-DISPLAY

Screen flicker or color distortion.

1. "SCREEN FLICKER OR COLOR DISTORTION "

2. DISPLAY SIGNAL CIRCUIT BETWEEN NAVIGATION ECU AND MULTI-DISPLAY CONTROLLER (⁽¹⁾)

3. DISPLAY SIGNAL CIRCUIT BETWEEN NAVIGATION ECU AND TELEVISION CAMERA ECU (⁽²⁾)

4. DISPLAY SIGNAL CIRCUIT BETWEEN MULTI-DISPLAY CONTROLLER AND TELEVISION CAMERA ECU (⁽¹⁾)

5. DISPLAY SIGNAL CIRCUIT BETWEEN TELEVISION CAMERA ECU AND MULTI-DISPLAY

6. Replace navigation ECU. See REMOVAL

7. Replace MULTI-DISPLAY

Navigation function switches can be operated while vehicle is running.

1. VEHICLE SPEED SIGNAL CIRCUIT BETWEEN MULTI-DISPLAY AND COMBINATION METER

DVD image cannot be displayed on front screen. (Parking brake is on.)

1. DISPLAY SIGNAL CIRCUIT BETWEEN MULTI-DISPLAY AND MULTI-DISPLAY CONTROLLER

2. PARKING BRAKE SWITCH CIRCUIT

3. Replace MULTI-DISPLAY

⁽¹⁾	With Rear Seat Entertainment System

⁽²⁾	Without Rear Seat Entertainment System

Navigation function

SYMPTOM CHART (NAVIGATION FUNCTION)

Symptom	Suspected area
Map disc cannot be inserted.	1. "MAP DISC CANNOT BE INSERTED "
	2. NAVIGATION ECU POWER SOURCE CIRCUIT
	3. Replace navigation ECU. See REMOVAL
Map disc cannot be ejected.	1. NAVIGATION ECU POWER SOURCE CIRCUIT
Map disc cannot be ejected.	2. Replace navigation ECU. See REMOVAL
Vehicle position mark deviates greatly.	1. "VEHICLE POSITION MARK DEVIATES GREATLY "
	2. REPLACE GPS ANTENNA
	3. Replace navigation ECU. See REMOVAL
Vehicle position mark is not updated.	1. "VEHICLE POSITION MARK IS NOT UPDATED "
	2. Replace map disc
	3. Replace navigation ECU. See REMOVAL
Current position display does not appear.	1. "CURRENT POSITION DISPLAY DOES NOT APPEAR "
	2. REPLACE GPS ANTENNA
	3. Replace navigation ECU. See REMOVAL
GPS mark is not displayed.	1. "GPS MARK IS NOT DISPLAYED "
	2. REPLACE GPS ANTENNA
	3. Replace navigation ECU. See REMOVAL
Voice guidance does not function.	1. "VOICE GUIDANCE DOES NOT FUNCTION "
	2. Mute signal circuit between stereo component amplifier and navigation ECU
	3. NAVIGATION VOICE SPEAKER CIRCUIT
	4. Replace map disc
	5. Replace navigation ECU. See REMOVAL
Map display incomplete	1. "MAP DISPLAY INCOMPLETE "
	2. Replace map disc
	3. Replace navigation ECU. See REMOVAL
Route cannot be calculated.	1. "ROUTE CANNOT BE CALCULATED "
	2. Replace map disc
	3. Replace navigation ECU. See REMOVAL
Voice recognition difficulty	1. "VOICE RECOGNITION DIFFICULTY "
Voice recognition difficulty	2. Replace navigation ECU. See REMOVAL
Voice is not recognized.	1. "VOICE IS NOT RECOGNIZED "
	2. MICROPHONE CIRCUIT BETWEEN OVERHEAD J/B AND MULTI-DISPLAY
	3. MICROPHONE CIRCUIT BETWEEN MULTI-DISPLAY AND NAVIGATION ECU
	4. STEERING PAD SWITCH CIRCUIT
	5. Replace MICROPHONE
	6. Replace overhead J/B. See MICROPHONE AMPLIFIER
	7. Replace navigation ECU. See REMOVAL
	8. Replace MULTI-DISPLAY
	9. Replace RADIO RECEIVER

Steering pad switch function

STEERING PAD SWITCH FUNCTION

Symptom	Suspected area
Voice navigation cannot be operated with steering pad switch.	1. STEERING PAD SWITCH CIRCUIT
	2. Replace RADIO RECEIVER
	3. Replace navigation ECU. See REMOVAL

Bluetooth function

BLUETOOTH FUNCTION

Symptom	Suspected area
Cellular phone registration failure, phone directory transfer failure	1. "CELLULAR PHONE REGISTRATION FAILURE, PHONE DIRECTORY TRANSFER FAILURE "
Cellular phone cannot send/receive.	1. "CELLULAR PHONE CANNOT SEND/RECEIVE "
	2. CELLULAR PHONE VOICE CIRCUIT BETWEEN MULTI-DISPLAY AND NAVIGATION ECU
	3. Replace MULTI-DISPLAY
	4. Replace navigation ECU. See REMOVAL
Cannot call in a certain place.	1. "CANNOT CALL IN A CERTAIN PLACE "
The other callers voice cannot be heard, is too quiet, or distorted.	1. "The Other Callers Voice cannot be Heard, is too Quiet, or Distorted"
	2. Replace navigation ECU. See REMOVAL
	3. Replace MULTI-DISPLAY
The other caller cannot hear your voice, or your voice is too quiet or distorted.	1. "The Other Caller cannot Hear Your Voice, or Your Voice is too Quiet or Distorted"