DTC 74-40
AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: 74-40: Short in Speaker Circuit
DTC 74-40 - Short in Speaker Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
After the inspection is completed, clear the DTCs.
PROCEDURE
1. CHECK AUDIO MODELS
(a) Check the audio model.
Result
B -- CHECK DTC
A -- Continue to next step.
2. CHECK FOR DTC
(a) Disconnect the F31, F4 and F3 amplifier connectors.
(b) Clear the DTCs.
(c) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
OK -- Continue to next step.
3. CHECK FOR DTC
(a) Reconnect the F3 amplifier connector.
(b) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
OK -- Continue to next step.
4. CHECK FOR DTC
(a) Reconnect the F31 amplifier connector.
(b) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
(a) Disconnect the F4 amplifier connector.
(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.
6. INSPECT FRONT NO. 1 SPEAKER ASSEMBLY
(a) Disconnect the I10 and I1 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 1 SPEAKER ASSEMBLY
OK -- Continue to next step.
7. INSPECT REAR HEADER SPEAKER ASSEMBLY
(a) Disconnect the S9 and S8 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE REAR HEADER SPEAKER ASSEMBLY
OK -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
8. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
(a) Disconnect the F3 amplifier connector.
(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.
9. INSPECT FRONT NO. 4 SPEAKER ASSEMBLY
(a) Disconnect the F6 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 4 SPEAKER ASSEMBLY
OK -- Continue to next step.
10. INSPECT REAR SPEAKER SET LH
(a) Disconnect the J17 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE REAR SPEAKER SET LH
OK -- Continue to next step.
11. INSPECT NO. 1 WOOFER BOX SPEAKER ASSEMBLY
(a) Disconnect the L4 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE NO. 1 WOOFER BOX SPEAKER ASSEMBLY
OK -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
12. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
(a) Disconnect the F31 amplifier connector.
(b) Disconnect the P2 ECU connector.*
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
*: w/ LEXUS Link System
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
13. INSPECT REAR SPEAKER SET RH
(a) Disconnect the J15 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE REAR SPEAKER SET RH
OK -- Continue to next step.
14. INSPECT REAR NO. 2 SPEAKER ASSEMBLY
(a) Disconnect the rear No. 2 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE REAR NO. 2 SPEAKER ASSEMBLY
OK -- Continue to next step.
15. CHECK REAR NO. 3 SPEAKER ASSEMBLY
(a) Disconnect the rear No. 3 speaker connectors.
(b) Interchange the rear No. 3 speaker LH with RH.
(c) Check that the malfunction disappears.
OK:
Malfunction disappears.
HINT:
- Connect all the connectors to the rear No. 3 speakers.
- When there is a possibility that either the right or left rear speaker is defective, inspect by interchanging the right one with the left one.
- Perform the inspection above on both the LH and RH sides.
NG -- INSPECT FRONT NO. 2 SPEAKER ASSEMBLY
OK -- REPLACE REAR NO. 3 SPEAKER ASSEMBLY
16. INSPECT FRONT NO. 2 SPEAKER ASSEMBLY
(a) Disconnect the F8 and F7 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 2 SPEAKER ASSEMBLY
OK -- Continue to next step.
17. CHECK FRONT NO. 3 SPEAKER ASSEMBLY
(a) Disconnect the F14 and F13 speaker connectors.
(b) Interchange the front No. 3 speaker LH with RH.
(c) Check that the malfunction disappears.
OK:
Malfunction disappears.
HINT:
- Connect all the connectors to the front No. 3 speakers.
- When there is a possibility that either the right or left front speaker is defective, inspect by interchanging the right one with the left one.
- Perform the inspection above on both the LH and RH sides.
NG -- CHECK HARNESS AND CONNECTOR (FRONT NO. 2 SPEAKER - FRONT NO. 3 SPEAKER)
OK -- REPLACE FRONT NO. 3 SPEAKER ASSEMBLY
18. CHECK HARNESS AND CONNECTOR (FRONT NO. 2 SPEAKER - FRONT NO. 3 SPEAKER)
(a) Disconnect the F8, F7, F14 and F13 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for LH
for RH
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
19. CHECK VEHICLE EQUIPMENT
(a) Check if the vehicle is equipped with the LEXUS Link System.
Result
B -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
A -- Continue to next step.
20. CHECK HARNESS AND CONNECTOR (TELEPHONE ECU - STEREO COMPONENT AMPLIFIER AND FRONT NO. 2 SPEAKER RH)
(a) Disconnect the F31 amplifier connector.
(b) Disconnect the F7 speaker connector.
(c) Disconnect the P2 ECU connector.
(d) 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.
21. REPLACE STEREO COMPONENT AMPLIFIER WITH NORMAL ONE AND CHECK
(a) Replace the stereo component amplifier with a normal one and check if the same problem occurs again Removal.
OK:
Same problem does not occur.
NG -- REPLACE TELEPHONE ECU ASSEMBLY
OK -- END (STEREO COMPONENT AMPLIFIER IS DEFECTIVE)
22. CHECK DTC
(a) Disconnect the F3 and F31 amplifier connectors.
(b) Clear the DTCs.
(c) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
OK -- Continue to next step.
23. CHECK DTC
(a) Reconnect the F31 amplifier connector.
(b) Clear the DTCs.
(c) Check if DTC 74-40 is output.
OK:
DTC 74-40 is not output.
NG -- CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
OK -- Continue to next step.
24. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
(a) Disconnect the F3 amplifier connector.
(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.
25. INSPECT FRONT NO. 1 SPEAKER ASSEMBLY LH
(a) Disconnect the I10 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 1 SPEAKER ASSEMBLY LH
OK -- Continue to next step.
26. INSPECT FRONT NO. 4 SPEAKER ASSEMBLY
(a) Disconnect the F6 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 4 SPEAKER ASSEMBLY
OK -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
27. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)
(a) Disconnect the F31 amplifier connector.
(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.
28. INSPECT FRONT NO. 1 SPEAKER ASSEMBLY RH
(a) Disconnect the I1 speaker connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 1 SPEAKER ASSEMBLY RH
OK -- Continue to next step.
29. INSPECT REAR SPEAKER SET
(a) Disconnect the J17 and J15 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE REAR SPEAKER SET
OK -- Continue to next step.
30. INSPECT FRONT NO. 2 SPEAKER ASSEMBLY
(a) Disconnect the F8 and F7 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 2 SPEAKER ASSEMBLY
OK -- Continue to next step.
31. INSPECT FRONT NO. 3 SPEAKER ASSEMBLY
(a) Disconnect the F14 and F13 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FRONT NO. 3 SPEAKER ASSEMBLY
OK -- Continue to next step.
32. CHECK HARNESS AND CONNECTOR (FRONT NO. 2 SPEAKER - FRONT NO. 3 SPEAKER)
(a) Disconnect the F8, F7, F14 and F13 speaker connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for LH
for RH
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
33. CHECK VEHICLE EQUIPMENT
(a) Check if the vehicle is equipped with the LEXUS Link System.
Result
B -- REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY
A -- Continue to next step.
34. CHECK HARNESS AND CONNECTOR (TELEPHONE ECU - STEREO COMPONENT AMPLIFIER AND FRONT NO. 2 SPEAKER LH)
(a) Disconnect the F31 amplifier connector.
(b) Disconnect the F7 speaker connector.
(c) Disconnect the P2 ECU connector.
(d) 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.
35. REPLACE STEREO COMPONENT AMPLIFIER WITH NORMAL ONE AND CHECK
(a) Replace the stereo component amplifier with a normal one and check if the same problem occurs again Removal.
OK:
Same problem does not occur.
NG -- REPLACE TELEPHONE ECU ASSEMBLY
OK -- END (STEREO COMPONENT AMPLIFIER IS DEFECTIVE)