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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 output is stopped.

WIRING DIAGRAM













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

PROCEDURE

1. INSPECT STEREO COMPONENT AMPLIFIER
(a) Disconnect the stereo component amplifier connectors P29 and P28.
(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.
2. CHECK OPERATION
(a) Reconnect the stereo component amplifier connector P29.
(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.
3. 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:





*1: with Front Center Speaker
*2: without Front Center Speaker
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT FRONT NO. 1 SPEAKER (LEFT HAND)
(a) Resistance check.
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
with Front Center Speaker
6 to 10 Ohms
without Front Center Speaker
Approximately 4 Ohms
NG -- REPLACE FRONT NO. 1 SPEAKER (LEFT HAND)
OK -- Continue to next step.
5. CONFIRM MODEL
Result:






B -- INSPECT REAR STEREO COMPONENT SPEAKER (LEFT HAND)
A -- Continue to next step.
6. INSPECT REAR NO. 2 SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR NO. 2 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
7. INSPECT REAR NO. 2 SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR NO. 2 SPEAKER (LEFT HAND)
OK -- Continue to next step.
8. INSPECT REAR NO. 3 SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and rear No. 3 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR NO. 3 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
9. INSPECT REAR NO. 3 SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and rear No. 3 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
OK -- INSPECT WOOFER BOX SPEAKER
NG -- REPLACE REAR NO. 3 SPEAKER (LEFT HAND)
10. INSPECT REAR STEREO COMPONENT SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and rear stereo component speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR STEREO COMPONENT SPEAKER (LEFT HAND)
OK -- Continue to next step.
11. INSPECT REAR STEREO COMPONENT SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and rear stereo component speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR STEREO COMPONENT SPEAKER (RIGHT HAND)
OK -- Continue to next step.
12. INSPECT FRONT STEREO COMPONENT SPEAKER
(a) Resistance check.
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
7 to 9 Ohms
NG -- REPLACE FRONT STEREO COMPONENT SPEAKER
OK -- Continue to next step.
13. INSPECT WOOFER BOX SPEAKER





(a) Resistance check.
(b) Measure the resistance according to the value(s) in the table below.
NOTE: The speaker should not be removed for checking.

Standard resistance:
with Front Center Speaker






without Front Center Speaker






NG -- REPLACE WOOFER BOX SPEAKER
OK -- Continue to next step.
14. 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:





*1: with Front Center Speaker
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
15. INSPECT FRONT NO. 1 SPEAKER (RIGHT HAND)
(a) Resistance check.
(1) Measure the resistance between the terminals of the speaker.
Standard resistance:
with Front Center Speaker
6 to 10 Ohms
without Front Center Speaker
Approximately 4 Ohms
NG -- REPLACE FRONT NO. 1 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
16. INSPECT FRONT NO. 2 SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and front No. 2 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE FRONT NO. 2 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
17. INSPECT FRONT NO. 2 SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and front No. 2 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE FRONT NO. 2 SPEAKER (LEFT HAND)
OK -- Continue to next step.
18. INSPECT FRONT NO. 3 SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and front No. 3 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE FRONT NO. 3 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
19. INSPECT FRONT NO. 3 SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and front No. 3 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE FRONT NO. 3 SPEAKER (LEFT HAND)
OK -- Continue to next step.
20. CONFIRM MODEL
Result:






B -- INSPECT REAR SPEAKER (LEFT HAND)
A -- Continue to next step.
21. INSPECT REAR NO. 2 SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR NO. 2 SPEAKER (RIGHT HAND)
OK -- Continue to next step.
22. INSPECT REAR NO. 2 SPEAKER (LEFT HAND)
(a) Reconnect the stereo component amplifier connector and rear No. 2 speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR NO. 2 SPEAKER (LEFT HAND)
OK -- Continue to next step.
23. INSPECT REAR SPEAKER (RIGHT HAND)
(a) Reconnect the stereo component amplifier connector and rear speaker connector.
(b) Check that audio sound can be heard from the speaker.
OK:
Audio sound can be heard.
NG -- REPLACE REAR SPEAKER (RIGHT HAND)
OK -- REPLACE REAR SPEAKER (LEFT HAND)
24. 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 -- REPLACE REAR SPEAKER (RIGHT HAND)