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NAVIGATION: NAVIGATION SYSTEM: 74-40: Short in Speaker Circuit

DTC 74-40 - Short in Speaker Circuit

DESCRIPTION





This circuit has a fail-safe function.

- When a short in the speaker circuit is detected, all sound outputs are stopped.

WIRING DIAGRAM









INSPECTION PROCEDURE
HINT: After the inspection is completed, clear the DTCs.

PROCEDURE

1. CONFIRM MODEL
Result:






B -- INSPECT STEREO COMPONENT AMPLIFIER
A -- Continue to next step.
2. INSPECT STEREO COMPONENT AMPLIFIER
(a) Disconnect the stereo component amplifier connectors S28 and S35.
(b) Clear the DTCs and recheck for DTCs.
(c) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- REPLACE STEREO COMPONENT AMPLIFIER
OK -- Continue to next step.
3. CHECK OPERATION
(a) Reconnect the stereo component amplifier connector S35.
(b) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- CHECK HARNESS AND CONNECTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR




(a) Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT FRONT NO. 1 SPEAKER (RIGHT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
7 to 9 Ohms
NG -- REPLACE FRONT NO. 1 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
6. INSPECT REAR SPEAKER (RIGHT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
14 to 18 Ohms
NG -- REPLACE REAR SPEAKER (RIGHT HAND)
OK -- Continue to next step.
7. INSPECT REAR SPEAKER (LEFT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
14 to 18 Ohms
NG -- REPLACE REAR SPEAKER (LEFT HAND)
OK -- Continue to next step.
8. INSPECT FRONT NO. 2 SPEAKER (LEFT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
7 to 9 Ohms
NG -- REPLACE FRONT NO. 2 SPEAKER (LEFT HAND)
OK -- Continue to next step.
9. INSPECT FRONT NO. 2 SPEAKER (RIGHT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
7 to 9 Ohms
NG -- REPLACE FRONT NO. 2 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
10. INSPECT FRONT STEREO COMPONENT SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and front stereo component speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE FRONT STEREO COMPONENT SPEAKER (LEFT HAND)
OK -- REPLACE FRONT STEREO COMPONENT SPEAKER (RIGHT HAND)
11. CHECK HARNESS AND CONNECTOR




(a) Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
12. INSPECT FRONT NO. 1 SPEAKER (LEFT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
7 to 9 Ohms
NG -- REPLACE FRONT NO. 1 SPEAKER (LEFT HAND)
OK -- REPLACE FRONT NO. 2 SPEAKER (CENTER)
13. INSPECT STEREO COMPONENT AMPLIFIER
(a) Disconnect the stereo component amplifier connectors S30 and S35.
(b) Clear the DTCs and recheck for DTCs.
(c) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- REPLACE STEREO COMPONENT AMPLIFIER
OK -- Continue to next step.
14. CHECK OPERATION
(a) Reconnect the stereo component amplifier connector S35.
(b) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- CHECK HARNESS AND CONNECTOR
OK -- Continue to next step.
15. CHECK HARNESS AND CONNECTOR




(a) Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
16. INSPECT REAR SPEAKER (RIGHT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
Approximately 4 Ohms
NG -- REPLACE REAR SPEAKER (RIGHT HAND)
OK -- Continue to next step.
17. INSPECT REAR SPEAKER (LEFT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
Approximately 4 Ohms
NG -- REPLACE REAR SPEAKER (LEFT HAND)
OK -- Continue to next step.
18. INSPECT FRONT NO. 2 SPEAKER (LEFT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
Approximately 4 Ohms
NG -- REPLACE FRONT NO. 2 SPEAKER (LEFT HAND)
OK -- Continue to next step.
19. INSPECT FRONT NO. 2 SPEAKER (RIGHT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
Approximately 4 Ohms
NG -- REPLACE FRONT NO. 2 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
20. INSPECT FRONT STEREO COMPONENT SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and front stereo component speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE FRONT STEREO COMPONENT SPEAKER (LEFT HAND)
OK -- REPLACE FRONT STEREO COMPONENT SPEAKER (RIGHT HAND)
21. CHECK HARNESS AND CONNECTOR




(a) Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
22. INSPECT FRONT NO. 1 SPEAKER (RIGHT HAND)
(a) Resistance check
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
Approximately 2 Ohms
NG -- REPLACE FRONT NO. 1 SPEAKER (RIGHT HAND)
OK -- REPLACE FRONT NO. 1 SPEAKER (LEFT HAND)