Electrical - One Horn Inoperative Or Poor Sound Quality
90 Dual-tone horn: One horn will not work or has poor sound quality90 10 08
2017859/3
June 15, 2010
Supersedes Technical Service Bulletin Group 90 number 08-08 dated November 5, 2008 for reasons listed below.
Affected Vehicles
Condition
^ The high tone or low tone horn does not function.
^ Poor sound quality from one or both horns.
Technical Background
The vibrations caused when using the horn are transmitted through the steel bracket to the bumper carrier.
Inoperable high or low horn: The horn cannot properly vibrate, as the bracket and the bumper carrier vibrate
with the same frequency. As a result, the horn draws more current during operation, which may cause the horn to
become overloaded and eventually fail.
Poor horn sound quality: The horn vibrates, but the bumper carrier also vibrates, partly superimposing the
output of the horn. This affects the sound quality of the horn.
Production Solution
Improved horn mounting bracket made of aluminum.
Service
If the horn is inoperable:
1. Visually inspect the electrical harness connector to the horn for corroded, backed-out or widened contacts.
2. Check the voltage supply to the inoperable horn. Replace the horn if the voltage supply is correct.
3. If a steel bracket is installed, replace it with a new aluminum bracket, part number 8E0 951 229E.
a. Remove the front bumper.
b. Attach the bracket in the sequence specified by Figure 1.
If the horn has poor sound quality:
1. Check the current draw of the horn during operation. The specified values with 13.8V vehicle battery voltage (engine running or battery charger connected) are as follows:
^ Low-tone horn: 5.2 A to 6.0 A.
^ High-tone horn: 4.5 A to 5.6 A.
2. If the current draw is not correct, replace the horn.
3. If a steel bracket is installed, replace it with a new aluminum bracket, part number 8E0 951 229E.
a. Remove the front bumper.
b. Attach the bracket in the sequence specified by Figure 1.
Warranty
Vehicles without intercooler/Vehicles With intercooler.
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.