Audio System - Buzzing From Rear Speakers
Bulletin No.: 04-08-44-014ADate: September 03, 2004
ADVANCE SERVICE INFORMATION RESOLUTION
Subject:
Buzz Type Noise Coming From Rear Speakers (Twist/Shield Speaker Wires and Relocate Ground)
Models:
2004 Buick Rainier
2004 Chevrolet TrailBlazer, TrailBlazer EXT
2004 GMC Envoy, Envoy XL, Envoy XUV
2004 Oldsmobile Bravada
with Speaker System Premium Performance Enhanced (Bose(R)) Audio (RPO UQA) and A4WD/AWD
Built After November 1, 2003 (Non Class 2 System)
Supercede:
This bulletin is being revised to provide the correction information, which is now available for Advanced Service Information Bulletin Number 04-08-44-014. Please discard Corporate Bulletin Number 04-08-44-014 (Section 08 - Body and Accessories).
Condition
Some customers may comment on a buzz type noise heard through the rear speakers. This noise can only be heard when the radio is on, volume low and while driving in A4WD/AWD mode. The noise USUALLY occurs above 32 km/h (20 mph) and is related to the active transfer case operation.
Correction
Perform the following procedure to reduce the rear speaker buzz noise caused by the active transfer case.
1. Remove the left side I/P closeout panel.
2. Remove the transfer case control module and mounting bracket from the I/P mag beam.
3. Disconnect the C3 connector from the transfer case control module.
4. Remove the wire and terminal from cavity A (circuit 2250) from C3 connector. Tape back.
5. Construct new ground wire using terminals P/N 12047767 and P/N 12089496. Route this wire through the grommet from the IP out to the engine compartment.
6. Install the new ring terminal onto ground stud (G105) located on the bulkhead just above the brake booster.
7. Install the new terminal into cavity A of connector C3.
8. Connect the C3 connector to the transfer case control module.
9. Install the transfer case control module and mounting bracket to the I/P mag beam.
10. Install the left side I/P closeout panel.
11. Remove the console floor bracket from the vehicle.
12. Remove the rear seat audio module from the console.
13. Remove the console harness from the console.
14. On the console harness, remove the following circuits from the inline to IP connector (C307) and twist together (minimum of 1 twist per inch) in 4 separate pairs. Mark like color wires with cavity location.
^ B1 (circuit 199, brown) and B5 (circuit 116, yellow)
^ A8 (circuit 599, brown) and B3 (circuit 1547, brown)
^ B2 (circuit 46, dark blue) and B6 (circuit 115, light blue)
^ A9 (circuit 546, dark blue) and A1 (circuit 1946, black)
15. Repin the circuits as follows and then wrap foil tape GM P/N 10184916, around the outside of all 4 twisted pairs ensuring that there are no gaps in the taping around the twisted wires.
^ B1 (circuit 199, brown) to B6
^ B5 (circuit 116, yellow) to B5 (original location)
^ A8 (circuit 599, brown) to A8 (original location)
^ B3 (circuit 1547, brown) to A9
^ B2 (circuit 46, dark blue) to B2 (original location)
^ B6 (circuit 115, light blue) to B3
^ A9 (circuit 546, dark blue) to B1
^ A1 (circuit 1946, black) to A1 (original location)
Important:
Circuit 199 requires new terminal P/N 15304711 and circuit 115 requires new terminal P/N 12191811.
16. Ground the foil tape utilizing a 14 gauge wire where one end is contacting the conductive side of the foil tape and the other end is placed in cavity B8. Use terminal P/N 12191811. Wrap the wire and harness with vinyl electrical tape.
17. Install the console harness into the console.
18. Install the rear seat audio module to the console.
19. On the IP side of connector C307, repin the following circuits.
^ B1 (circuit 199, brown) to B6
^ B3 (circuit 1547, brown) to A9
^ B6 (circuit 115, light blue) to B3
^ A9 (circuit 546, dark blue) to B1
Important:
Circuit 199 (B1) requires new terminal P/N 15304728 and circuit 115 (B6) requires new terminal P/N 15304701.
20. On the IP side of connector C307, add the remaining ground for the foil tape. Connect one end to ground G102 located in the engine compartment at the left fender. Place the other end into cavity B8 using terminal P/N 15304701. Route along existing harness and secure with tape.
21. Install the console floor bracket into the vehicle.
Part Information
Warranty Information
For vehicles repaired under warranty, use the table.
Disclaimer