Navigation Multi Info Display. Dtc B15C3 Speaker Output Short

DTC Code	DTC Detection Condition	Trouble Area
B15C3	A short is detected in the speaker output circuit.	Speakers Harness or connector Stereo component amplifier assembly Navigation receiver assembly

WIRING DIAGRAM

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Navigation Multi Info Display.Navigation System (For Radio And Display Type).
Dtc
B15C3 Speaker Output Short

INSPECTION PROCEDURE

1.CHECK FOR DTC

Clear the DTCs (LandCruiser RM0000011BU0W7X.html).

Check for DTCs (LandCruiser RM0000011BU0W7X.html).
OK:
No DTCs are output.

Go to step 2

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)

2.CHECK VEHICLE CONDITION

Check the vehicle condition.
Result
Result
Proceed to
for JBL Made
A
except JBL Made
B

Result
Result	Proceed to
for JBL Made	A
except JBL Made	B

Go to step 13

A

3.CHECK HARNESS AND CONNECTOR (SPEAKER CIRCUIT)

*1: for RH Side
*2: for LH Side

Disconnect the J4*1 and/or K3*2 front No. 1 speaker assembly connector.

Disconnect the H10*1 and/or H13*2 front No. 2 speaker assembly connector.

Disconnect the H21*1 and/or H22*2 front No. 3 speaker assembly connector.

Disconnect the H14 front No. 4 speaker assembly connector.

Disconnect the L1*1 and/or M1*2 rear speaker set connector.

Disconnect the L3*1 and/or M3*2 rear No. 2 speaker assembly connector.

Disconnect the Q15*1 and/or R13*2 rear header speaker assembly connector.

Disconnect the R24 No. 1 speaker with box assembly connector.

Disconnect the H65 and H66 stereo component amplifier assembly connectors.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
H65-4 (FR+) - H21-1 (TWR+)*1	Always	Below 1 Ω
H65-10 (FR-) - H21-2 (TWR-)*1	Always	Below 1 Ω
H21-3 (+) - H10-2*1	Always	Below 1 Ω
H21-4 (-) - H10-1*1	Always	Below 1 Ω
H66-10 (WFR+) - J4-1*1	Always	Below 1 Ω
H66-9 (WFR-) - J4-2*1	Always	Below 1 Ω
H65-3 (FL+) - H22-1 (TWL+)*2	Always	Below 1 Ω
H65-9 (FL-) - H22-2 (TWL-)*2	Always	Below 1 Ω
H22-3 (+) - H13-2*2	Always	Below 1 Ω
H22-4 (-) - H13-1*2	Always	Below 1 Ω
H65-1 (WF1+) - R24-1 (WF1+)	Always	Below 1 Ω
H65-5 (WF1-) - R24-3 (WF1-)	Always	Below 1 Ω
H65-2 (WF2+) - R24-2 (WF2+)	Always	Below 1 Ω
H65-6 (WF2-) - R24-4 (WF2-)	Always	Below 1 Ω
H66-2 (MR+) - Q15-2*1	Always	Below 1 Ω
H66-7 (MR-) - Q15-1*1	Always	Below 1 Ω
H66-3 (WFL+) - K3-1*2	Always	Below 1 Ω
H66-8 (WFL-) - K3-2*2	Always	Below 1 Ω
H66-5 (RR+) - L3-1 (+TW)*1	Always	Below 1 Ω
H66-12 (RR-) - L3-2 (-TW)*1	Always	Below 1 Ω
L3-3 (+) - L1-1*1	Always	Below 1 Ω
L3-4 (-) - L1-2*1	Always	Below 1 Ω
H66-4 (RL+) - M3-1 (+TW)*2	Always	Below 1 Ω
H66-11 (RL-) - M3-2 (-TW)*2	Always	Below 1 Ω
M3-3 (+) - M1-1*2	Always	Below 1 Ω
M3-4 (-) - M1-2*2	Always	Below 1 Ω
H66-1 (ML+) - R13-2*2	Always	Below 1 Ω
H66-6 (ML-) - R13-1*2	Always	Below 1 Ω
H65-8 (CTR+) - H14-2	Always	Below 1 Ω
H66-7 (CTR-) - H14-1	Always	Below 1 Ω
H65-4 (FR+) - Body ground*1	Always	10 kΩ or higher
H65-10 (FR-) - Body ground*1	Always	10 kΩ or higher
H21-3 (+) - Body ground*1	Always	10 kΩ or higher
H21-4 (-) - Body ground*1	Always	10 kΩ or higher
H66-10 (WFR+) - Body ground*1	Always	10 kΩ or higher
H66-9 (WFR-) - Body ground*1	Always	10 kΩ or higher
H65-3 (FL+) - Body ground*2	Always	10 kΩ or higher
H65-9 (FL-) - Body ground*2	Always	10 kΩ or higher
H22-3 (+) - Body ground*2	Always	10 kΩ or higher
H22-4 (-) - Body ground*2	Always	10 kΩ or higher
H65-1 (WF1+) - Body ground	Always	10 kΩ or higher
H65-5 (WF1-) - Body ground	Always	10 kΩ or higher
H65-2 (WF2+) - Body ground	Always	10 kΩ or higher
H65-6 (WF2-) - Body ground	Always	10 kΩ or higher
H66-2 (MR+) - Body ground*1	Always	10 kΩ or higher
H66-7 (MR-) - Body ground*1	Always	10 kΩ or higher
H66-3 (WFL+) - Body ground*2	Always	10 kΩ or higher
H66-8 (WFL-) - Body ground*2	Always	10 kΩ or higher
H66-5 (RR+) - Body ground*1	Always	10 kΩ or higher
H66-12 (RR-) - Body ground*1	Always	10 kΩ or higher
L3-3 (+) - Body ground*1	Always	10 kΩ or higher
L3-4 (-) - Body ground*1	Always	10 kΩ or higher
H66-4 (RL+) - Body ground*2	Always	10 kΩ or higher
H66-11 (RL-) - Body ground*2	Always	10 kΩ or higher
M3-3 (+) - Body ground*2	Always	10 kΩ or higher
M3-4 (-) - Body ground*2	Always	10 kΩ or higher
H66-1 (ML+) - Body ground*2	Always	10 kΩ or higher
H66-6 (ML-) - Body ground*2	Always	10 kΩ or higher
H65-8 (CTR+) - Body ground	Always	10 kΩ or higher
H66-7 (CTR-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.INSPECT FRONT NO. 1 SPEAKER ASSEMBLY

Remove the front No. 1 speaker assembly (LandCruiser RM000002MK7039X.html).

Inspect the front No. 1 speaker assembly (LandCruiser RM000002MK5028X.html).

REPLACE FRONT NO. 1 SPEAKER ASSEMBLY (LandCruiser RM000002MK7039X.html)

OK

5.INSPECT FRONT NO. 2 SPEAKER ASSEMBLY

Remove the front No. 2 speaker assembly (LandCruiser RM000000VEO04BX.html).

Inspect the front No. 2 speaker assembly (LandCruiser RM000000VEM033X.html).

REPLACE FRONT NO. 2 SPEAKER ASSEMBLY (LandCruiser RM000000VEO04BX.html)

OK

6.CHECK FRONT NO. 3 SPEAKER ASSEMBLY

Replace the front No. 3 speaker assembly with a known good one (LandCruiser RM000003AW801GX.html).

Check that the malfunction disappears.
NOTICE:
1. Connect all the connectors that were disconnected to the front No. 3 speaker assemblies.
2. Perform the above inspection on both LH and RH sides.
OK:
No DTCs are output.

Go to step 7

END (FRONT NO. 3 SPEAKER ASSEMBLY IS DEFECTIVE)

7.CHECK FRONT NO. 4 SPEAKER ASSEMBLY

Replace the front No. 4 speaker assembly with a known good one (LandCruiser RM000000VEO04BX.html).

Check that the malfunction disappears.
OK:
No DTCs are output.

Go to step 8

END (FRONT NO. 4 SPEAKER ASSEMBLY IS DEFECTIVE)

8.INSPECT REAR SPEAKER SET

Remove the rear speaker set (LandCruiser RM000002MKB042X.html).

Inspect the rear speaker set (LandCruiser RM000002MK902UX.html).

REPLACE REAR SPEAKER SET (LandCruiser RM000002MKB042X.html)

OK

9.CHECK REAR NO. 2 SPEAKER ASSEMBLY

Replace the rear No. 2 speaker assembly with a known good one (LandCruiser RM000002MKB042X.html).

Check that the malfunction disappears.
NOTICE:
1. Connect all the connectors that were disconnected to the rear No. 2 speaker assemblies.
2. Perform the above inspection on both LH and RH sides.
OK:
No DTCs are output.

Go to step 10

END (REAR NO. 2 SPEAKER ASSEMBLY IS DEFECTIVE)

10.CHECK REAR HEADER SPEAKER ASSEMBLY

Replace the rear header speaker assembly with a known good one (LandCruiser RM000003FS302RX.html).

Check that the malfunction disappears.
NOTICE:
1. Connect all the connectors that were disconnected to the rear header speaker assemblies.
2. Perform the above inspection on both LH and RH sides.
OK:
No DTCs are output.

Go to step 11

END (REAR HEADER SPEAKER ASSEMBLY IS DEFECTIVE)

11.INSPECT NO. 1 SPEAKER WITH BOX ASSEMBLY

Remove the No. 1 speaker with box assembly (LandCruiser RM000003FS302RX.html).

Inspect the No. 1 speaker with box assembly (LandCruiser RM000002ZX4025X.html).

REPLACE NO. 1 SPEAKER WITH BOX ASSEMBLY (LandCruiser RM000003FS302RX.html)

OK

12.CHECK STEREO COMPONENT AMPLIFIER ASSEMBLY

Replace the stereo component amplifier assembly with a known good one (LandCruiser RM000003AI9027X.html).

Check that the malfunction disappears.
OK:
No DTCs are output.

REPLACE NAVIGATION RECEIVER ASSEMBLY (LandCruiser RM000003B6H02GX.html)

END (STEREO COMPONENT AMPLIFIER ASSEMBLY IS DEFECTIVE)

13.CHECK VEHICLE CONDITION

Check the vehicle condition.
Result
Result
Proceed to
for 14 Speakers
A
for 9 Speakers
B

Go to step 24

A

14.CHECK HARNESS AND CONNECTOR (SPEAKER CIRCUIT)

*1: for RH Side
*2: for LH Side

Disconnect the J4*1 and/or K3*2 front No. 1 speaker assembly connector.

Disconnect the H10*1 and/or H13*2 front No. 2 speaker assembly connector.

Disconnect the H21*1 and/or H22*2 front No. 3 speaker assembly connector.

Disconnect the H14 front No. 4 speaker assembly connector.

Disconnect the L1*1 and/or M1*2 rear speaker set connector.

Disconnect the L3*1 and/or M3*2 rear No. 2 speaker assembly connector.

Disconnect the Q15*1 and/or R13*2 rear header speaker assembly connector.

Disconnect the R24 No. 1 speaker with box assembly connector.

Disconnect the H67 stereo component amplifier assembly connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
H67-13 (FR+) - H21-1 (TWR+)*1	Always	Below 1 Ω
H67-28 (FR-) - H21-2 (TWR-)*1	Always	Below 1 Ω
H21-3 (+) - H10-2*1	Always	Below 1 Ω
H21-4 (-) - H10-1*1	Always	Below 1 Ω
H67-5 (WFR+) - J4-1*1	Always	Below 1 Ω
H67-20 (WFR-) - J4-2*1	Always	Below 1 Ω
H67-12 (FL+) - H22-1 (TWL+)*2	Always	Below 1 Ω
H67-27 (FL-) - H22-2 (TWL-)*2	Always	Below 1 Ω
H22-3 (+) - H13-2*2	Always	Below 1 Ω
H22-4 (-) - H13-1*2	Always	Below 1 Ω
H67-6 (WF1+) - R24-1 (WF1+)	Always	Below 1 Ω
H67-21 (WF1-) - R24-3 (WF1-)	Always	Below 1 Ω
H67-9 (MR+) - Q15-2*1	Always	Below 1 Ω
H67-24 (MR-) - Q15-1*1	Always	Below 1 Ω
H67-4 (WFL+) - K3-1*2	Always	Below 1 Ω
H67-19 (WFL-) - K3-2*2	Always	Below 1 Ω
H67-15 (RR+) - L3-1 (+TW)*1	Always	Below 1 Ω
H67-30 (RR-) - L3-2 (-TW)*1	Always	Below 1 Ω
L3-3 (+) - L1-1*1	Always	Below 1 Ω
L3-4 (-) - L1-2*1	Always	Below 1 Ω
H67-14 (RL+) - M3-1 (+TW)*2	Always	Below 1 Ω
H67-29 (RL-) - M3-2 (-TW)*2	Always	Below 1 Ω
M3-3 (+) - M1-1*2	Always	Below 1 Ω
M3-4 (-) - M1-2*2	Always	Below 1 Ω
H67-8 (ML+) - R13-2*2	Always	Below 1 Ω
H67-23 (ML-) - R13-1*2	Always	Below 1 Ω
H67-7 (CTR+) - H14-2	Always	Below 1 Ω
H67-22 (CTR-) - H14-1	Always	Below 1 Ω
H67-13 (FR+) - Body ground*1	Always	10 kΩ or higher
H67-28 (FR-) - Body ground*1	Always	10 kΩ or higher
H21-3 (+) - Body ground*1	Always	10 kΩ or higher
H21-4 (-) - Body ground*1	Always	10 kΩ or higher
H67-5 (WFR+) - Body ground*1	Always	10 kΩ or higher
H67-20 (WFR-) - Body ground*1	Always	10 kΩ or higher
H67-12 (FL+) - Body ground*2	Always	10 kΩ or higher
H67-27 (FL-) - Body ground*2	Always	10 kΩ or higher
H22-3 (+) - Body ground*2	Always	10 kΩ or higher
H22-4 (-) - Body ground*2	Always	10 kΩ or higher
H67-6 (WF1+) - Body ground	Always	10 kΩ or higher
H67-21 (WF1-) - Body ground	Always	10 kΩ or higher
H67-9 (MR+) - Body ground*1	Always	10 kΩ or higher
H67-24 (MR-) - Body ground*1	Always	10 kΩ or higher
H67-4 (WFL+) - Body ground*2	Always	10 kΩ or higher
H67-19 (WFL-) - Body ground*2	Always	10 kΩ or higher
H67-15 (RR+) - Body ground*1	Always	10 kΩ or higher
H67-30 (RR-) - Body ground*1	Always	10 kΩ or higher
L3-3 (+) - Body ground*1	Always	10 kΩ or higher
L3-4 (-) - Body ground*1	Always	10 kΩ or higher
H67-14 (RL+) - Body ground*2	Always	10 kΩ or higher
H67-29 (RL-) - Body ground*2	Always	10 kΩ or higher
M3-3 (+) - Body ground*2	Always	10 kΩ or higher
M3-4 (-) - Body ground*2	Always	10 kΩ or higher
H67-8 (ML+) - Body ground*2	Always	10 kΩ or higher
H67-23 (ML-) - Body ground*2	Always	10 kΩ or higher
H67-7 (CTR+) - Body ground	Always	10 kΩ or higher
H67-22 (CTR-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

15.INSPECT FRONT NO. 1 SPEAKER ASSEMBLY

Remove the front No. 1 speaker assembly (LandCruiser RM000002MK7039X.html).

Inspect the front No. 1 speaker assembly (LandCruiser RM000002MK5028X.html).

REPLACE FRONT NO. 1 SPEAKER ASSEMBLY (LandCruiser RM000002MK7039X.html)

OK

16.INSPECT FRONT NO. 2 SPEAKER ASSEMBLY

Remove the front No. 2 speaker assembly (LandCruiser RM000000VEO04BX.html).

Inspect the front No. 2 speaker assembly (LandCruiser RM000000VEM033X.html).
OK:
No DTCs are output.

REPLACE FRONT NO. 2 SPEAKER ASSEMBLY (LandCruiser RM000000VEO04BX.html)

OK

17.CHECK FRONT NO. 3 SPEAKER ASSEMBLY

Replace the front No. 3 speaker assembly with a known good one (LandCruiser RM000003AW801GX.html).

Check that the malfunction disappears.
NOTICE:
1. Connect all the connectors that were disconnected to the front No. 3 speaker assemblies.
2. Perform the above inspection on both LH and RH sides.
OK:
No DTCs are output.

Go to step 18

END (FRONT NO. 3 SPEAKER ASSEMBLY IS DEFECTIVE)

18.INSPECT FRONT NO. 4 SPEAKER ASSEMBLY

Remove the front No. 4 speaker assembly (LandCruiser RM000000VEO04BX.html).

Inspect the front No. 4 speaker assembly (LandCruiser RM000000VEM033X.html).

REPLACE FRONT NO. 4 SPEAKER ASSEMBLY (LandCruiser RM000000VEO04BX.html)

OK

19.INSPECT REAR SPEAKER SET

Remove the rear speaker set (LandCruiser RM000002MKB042X.html).

Inspect the rear speaker set (LandCruiser RM000002MK902UX.html).

REPLACE REAR SPEAKER SET (LandCruiser RM000002MKB042X.html)

OK

20.INSPECT REAR NO. 2 SPEAKER ASSEMBLY

Remove the rear No. 2 speaker assembly (LandCruiser RM000002MKB042X.html).

Inspect the rear No. 2 speaker assembly (LandCruiser RM000002MK902UX.html).

REPLACE REAR NO. 2 SPEAKER ASSEMBLY (LandCruiser RM000002MKB042X.html)

OK

21.INSPECT REAR HEADER SPEAKER ASSEMBLY

Remove the rear header speaker assembly (LandCruiser RM000003FS302RX.html).

Inspect the rear header speaker assembly (LandCruiser RM000002ZX4025X.html).

REPLACE REAR HEADER SPEAKER ASSEMBLY (LandCruiser RM000003FS302RX.html)

OK

22.INSPECT NO. 1 SPEAKER WITH BOX ASSEMBLY

Remove the No. 1 speaker with box assembly (LandCruiser RM000003FS302RX.html).

Inspect the No. 1 speaker with box assembly (LandCruiser RM000002ZX4025X.html).

REPLACE NO. 1 SPEAKER WITH BOX ASSEMBLY (LandCruiser RM000003FS302RX.html)

OK

23.CHECK STEREO COMPONENT AMPLIFIER ASSEMBLY

Replace the stereo component amplifier assembly with a known good one (LandCruiser RM000003AI9027X.html).

Check that the malfunction disappears.
OK:
No DTCs are output.

REPLACE NAVIGATION RECEIVER ASSEMBLY (LandCruiser RM000003B6H02GX.html)

END (STEREO COMPONENT AMPLIFIER ASSEMBLY IS DEFECTIVE)

24.CHECK HARNESS AND CONNECTOR (SPEAKER CIRCUIT)

*1: for RH Side
*2: for LH Side

Disconnect the J4*1 and/or K3*2 front No. 1 speaker assembly connector.

Disconnect the H10*1 and/or H13*2 front No. 2 speaker assembly connector.

Disconnect the H21*1 and/or H22*2 front No. 3 speaker assembly connector.

Disconnect the H14 front No. 4 speaker assembly connector.

Disconnect the L1*1 and/or M1*2 rear speaker set connector.

Disconnect the H67 stereo component amplifier assembly connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
H67-13 (FR+) - H21-1 (TWR+)*1	Always	Below 1 Ω
H67-28 (FR-) - H21-2 (TWR-)*1	Always	Below 1 Ω
H21-3 (+) - H10-2*1	Always	Below 1 Ω
H21-4 (-) - H10-1*1	Always	Below 1 Ω
H67-5 (WFR+) - J4-1*1	Always	Below 1 Ω
H67-20 (WFR-) - J4-2*1	Always	Below 1 Ω
H67-12 (FL+) - H22-1 (TWL+)*2	Always	Below 1 Ω
H67-27 (FL-) - H22-2 (TWL-)*2	Always	Below 1 Ω
H22-3 (+) - H13-2*2	Always	Below 1 Ω
H22-4 (-) - H13-1*2	Always	Below 1 Ω
H67-4 (WFL+) - K3-1*2	Always	Below 1 Ω
H67-19 (WFL-) - K3-2*2	Always	Below 1 Ω
H67-15 (RR+) - L1-1*1	Always	Below 1 Ω
H67-30 (RR-) - L1-2*1	Always	Below 1 Ω
H67-14 (RL+) - M1-1*2	Always	Below 1 Ω
H67-29 (RL-) - M1-2*2	Always	Below 1 Ω
H67-7 (CTR+) - H14-2	Always	Below 1 Ω
H67-22 (CTR-) - H14-1	Always	Below 1 Ω
H67-13 (FR+) - Body ground*1	Always	10 kΩ or higher
H67-28 (FR-) - Body ground*1	Always	10 kΩ or higher
H21-3 (+) - Body ground*1	Always	10 kΩ or higher
H21-4 (-) - Body ground*1	Always	10 kΩ or higher
H67-5 (WFR+) - Body ground*1	Always	10 kΩ or higher
H67-20 (WFR-) - Body ground*1	Always	10 kΩ or higher
H67-12 (FL+) - Body ground*2	Always	10 kΩ or higher
H67-27 (FL-) - Body ground*2	Always	10 kΩ or higher
H22-3 (+) - Body ground*2	Always	10 kΩ or higher
H22-4 (-) - Body ground*2	Always	10 kΩ or higher
H67-4 (WFL+) - Body ground*2	Always	10 kΩ or higher
H67-19 (WFL-) - Body ground*2	Always	10 kΩ or higher
H67-15 (RR+) - Body ground*1	Always	10 kΩ or higher
H67-30 (RR-) - Body ground*1	Always	10 kΩ or higher
H67-14 (RL+) - Body ground*2	Always	10 kΩ or higher
H67-29 (RL-) - Body ground*2	Always	10 kΩ or higher
H67-7 (CTR+) - Body ground	Always	10 kΩ or higher
H67-22 (CTR-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

25.INSPECT FRONT NO. 1 SPEAKER ASSEMBLY

Remove the front No. 1 speaker assembly (LandCruiser RM000002MK7039X.html).

Inspect the front No. 1 speaker assembly (LandCruiser RM000002MK5028X.html).

REPLACE FRONT NO. 1 SPEAKER ASSEMBLY (LandCruiser RM000002MK7039X.html)

OK

26.INSPECT FRONT NO. 2 SPEAKER ASSEMBLY

Remove the front No. 2 speaker assembly (LandCruiser RM000000VEO04BX.html).

Inspect the front No. 2 speaker assembly (LandCruiser RM000000VEM033X.html).
OK:
No DTCs are output.

REPLACE FRONT NO. 2 SPEAKER ASSEMBLY (LandCruiser RM000000VEO04BX.html)

OK

27.CHECK FRONT NO. 3 SPEAKER ASSEMBLY

Replace the front No. 3 speaker assembly with a known good one (LandCruiser RM000003AW801GX.html).

Check that the malfunction disappears.
NOTICE:
1. Connect all the connectors that were disconnected to the front No. 3 speaker assemblies.
2. Perform the above inspection on both LH and RH sides.
OK:
No DTCs are output.

Go to step 28

END (FRONT NO. 3 SPEAKER ASSEMBLY IS DEFECTIVE)

28.INSPECT FRONT NO. 4 SPEAKER ASSEMBLY

Remove the front No. 4 speaker assembly (LandCruiser RM000000VEO04BX.html).

Inspect the front No. 4 speaker assembly (LandCruiser RM000000VEM033X.html).

REPLACE FRONT NO. 4 SPEAKER ASSEMBLY (LandCruiser RM000000VEO04BX.html)

OK

29.INSPECT REAR SPEAKER SET

Remove the rear speaker set (LandCruiser RM000002MKB042X.html).

Inspect the rear speaker set (LandCruiser RM000002MK902UX.html).

REPLACE REAR SPEAKER SET (LandCruiser RM000002MKB042X.html)

OK

30.CHECK STEREO COMPONENT AMPLIFIER ASSEMBLY

Replace the stereo component amplifier assembly with a known good one (LandCruiser RM000003AI9027X.html).

Check that the malfunction disappears.
OK:
No DTCs are output.

REPLACE NAVIGATION RECEIVER ASSEMBLY (LandCruiser RM000003B6H02GX.html)

END (STEREO COMPONENT AMPLIFIER ASSEMBLY IS DEFECTIVE)