Rainier AWD L6-4.2L (2007)
Horn Switch: All Technical Service Bulletins
Horn - Inoperative When Pressing Horn Pad
TECHNICAL
Bulletin No.: 07-08-54-001C
Date: October 17, 2008
Subject:
EI07279 - Horn Inoperative from Steering Wheel Horn Pad (Ground Path Repair Procedure)
Models:
2006-2007 Buick Rainier
2006 Chevrolet TrailBlazer EXT
2006-2009 Chevrolet TrailBlazer
2006 GMC Envoy XL, Envoy XUV
2006-2009 GMC Envoy, Envoy Denali
Supercede:
This bulletin is being revised to provide field fix information. Please discard Corporate Bulletin Number 07-08-54-001B (Section 08 - Body and
Accessories).
Condition
Important:
If the horn does NOT work from the key fob horn button, disregard this bulletin and proceed with diagnosis/repair according to SI.
Some customers may comment that the horn is inoperative from the horn pad on the steering wheel.
Cause
The general cause of this condition is high resistance in the ground path through the steering column that energizes the horn relay. The key fob panic
button uses a different ground path and is not affected. A number of locations in the circuit have been identified as sources of the high resistance. It is
often difficult to pinpoint the specific location of the high resistance because the condition is usually intermittent. Attempting to discover the location can
be frustrating because as circuit components are moved, the condition will often disappear. A few locations have been identified as frequent contributors
to the problem.
Correction
Complete the following steps to diagnose and repair this condition:
1.
Does the horn work by depressing the button(s) on the key fob?
^
Yes - proceed with step 2.
^
No - do not proceed with this bulletin. Diagnose and repair using information found in SI.
2.
To aid in the diagnosis and to avoid disturbing others, disconnect the wiring harness from the horn assembly and insert appropriate connectors to
monitor the voltage with a multi-meter or a test light. If the horn pad is currently working, rotate the steering wheel lock to lock while depressing
the horn pad to determine if there are any spots in the rotation where the horn pad quits working.
Caution:
When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and
Enabling. Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system
