Booming Sound While Driving With Audio Unit On or Off
Booming sound while driving with audio unit on or offNOTE: Always check the connectors for poor connections or loose terminals.
1. Turn the ignition switch ON (II).
2. Operate the audio unit, and check the function of the speakers.
Is a booming sound or a low-frequency hum heard from speakers?
YES - Go to step 3.
NO - Go to no sound is heard from speakers.
3. Open the driver's door.
Is the booming sound or a low-frequency hum still present?
YES - Perform the electrical noise test. Sound Quality Diagnosis
NO - Go to step 4.
4. Turn the audio power switch OFF.
5. Do the self-diagnostic function.
6. Press the "No. 1" button.
Can you hear a low-frequency hum?
YES - Go to step 7.
NO - Go to step 8.
7. Check that the low-frequency hum sound continues sounding for about 1 minute.
Does the low-frequency hum sound continue sounding for about 1 minute?
YES - Go to step 28.
NO - Substitute a known-good active noise control unit and recheck. If the symptom/indication goes away, replace the original active noise control unit. If symptom is still present, substitute a known-good audio unit and recheck. If the symptom/indication goes away, replace the original audio unit.
8. Turn the ignition switch OFF.
9. Check the No. 32 (10 A) fuse in the driver's under-dash fuse/relay box.
Is the fuses OK?
YES - Go to step 10.
NO - Replace the fuse, and recheck.
10. Disconnect the active noise control unit 16P connector.
11. Measure the voltage between the active noise control unit 16P connector No. 8 terminal and body ground.
Is there battery voltage?
YES - Go to step 12.
NO - Repair open in the wire between the No. 32 (10 A) fuse in the driver's under-dash fuse/relay box and the active noise control unit 16P connector terminal No. 8.
12. Reconnect the active noise control unit 16P connector.
13. Measure the voltage between the active noise control unit 16P connector No. 7 terminal and body ground.
Is there less than 0.1 V?
YES - Go to step 14.
NO - Repair open in the wire between the active noise control unit 16P connector No. 7 terminal and body ground (G502).
14. Perform the self-diagnostic function. Initial Inspection and Diagnostic Overview
15. Press the "No. 1" button.
16. Measure the voltage between the active noise control unit 16P connector No. 12 terminal and body ground.
Is there about 5 V?
YES - Go to step 21.
NO - Go to step 17.
17. Turn the ignition switch OFF.
18. Disconnect the active noise control unit 16P connector and audio unit connector E (5P).
19. Check for continuity between the active noise control unit 16P connector No. 12 terminal and audio unit connector E (5P) terminal No. 5.
Is there continuity?
YES - Go to step 20.
NO - Repair open in the wire between the active noise control unit 16P connector No. 12 terminal and audio unit connector E (5P) terminal No. 15.
20. Check for continuity between body ground and the active noise control unit 16P connector terminal No. 12.
Is there continuity?
YES - Repair short in the wire between the active noise control unit 16P connector No. 12 terminal and audio unit connector E (5P) terminal No. 5.
NO - Replace the audio unit.
21. Perform the self-diagnostic function. Initial Inspection and Diagnostic Overview
22. Press and release the "No. 1" button.
23. Measure the voltage between the active noise control unit 16P connector No. 2 terminal and body ground.
Is there about 2.5 V?
YES - Replace the audio unit.
NO - Go to step 24.
24. Turn the ignition switch OFF.
25. Disconnect the active noise control unit 16P connector and audio unit connector E (5P).
26. Check for continuity between the active noise control unit 16P connector and audio unit connector E (5P).
Is there continuity?
YES - Go to step 27.
NO - Repair open in the wire(s) between the active noise control unit 16P connector and audio unit connector E (5P).
27. Check for continuity between body ground and active noise control unit 16P connector terminals No. 1, 2, 9, and 10 individually.
Is there continuity?
YES - Repair short in the wire(s) between the active noise control unit 16P connector and audio unit connector E(5P).
NO - Replace the active noise control unit.
28. Start the engine, and let the vehicle idle.
29. Perform the self-diagnostic function. Initial Inspection and Diagnostic Overview
30. Press the "No. 1" button.
Can you hear a low-frequency hum?
YES - Go to step 31.
NO - The system is OK.
31. Turn the ignition switch OFF.
32. Jump the SCS line with the HDS.
33. Disconnect the active noise control unit 16P connector and PCM connector A (31P).
34. Check for continuity between the active noise control unit 16Pconnector No. 15terminal and PCM connector A (49P) terminal No. 33.
Is there continuity?
YES - Go to step 35.
NO - Repair open in the wire between the active noise control unit 16P connector No. 15 terminal and PCM connector A (49P) terminal No. 33.
35. Check for continuity between the active noise control unit 16P connector No. 15 terminal and body ground.
Is there continuity?
YES - Repair short in the wire between body ground and the active noise control unit 16P connector No. 15 terminal and PCM connector A (49P) terminal No. 33.
NO - Replace the PCM.