File in Section:
Bulletin No.:

Service Bulletin

Date:

PI1107
November, 2013

PRELIMINARY INFORMATION
Subject:

Normal Characteristic – High Pitched Whine or Squeal Noise Coming from Front
Wheel Area

Models:

2010-2014 Cadillac SRX
Equipped with Continuously Variable Real Time Damping Suspension (RPO F45)

Condition/Concern
Some customers may comment on a faint high pitched whine or squeal noise coming from the front wheel area. The
noise will be more apparent when the vehicle is stopped in close quarters (i.e. a garage) with little ambient noise. As
vehicle speed increases, the sound will be drowned out by normal engine and road noise.
The noise that is heard may be the sound of electrical current going through the coils of the strut and shock dampers
for the electronic suspension control system. The electrical current is the source of the variable damping. During
normal operation, the current values are expected to be near 100mA during wake up with engine off. When the
engine is in RUN mode, the current goes to its steady state current of approximately 500mA. This change in current
may cause the tone to change slightly. While driving over 5 km/h (3 mph), the dampers are in a normal/regulated
mode. This means that the current goes to a softer setting (approximately 1600mA) and will adjust the firmness
(reduce the current) based on driving conditions and vehicle/road input. This change in current can also affect the
tone of the hum.

Recommendation/Instructions
This is a normal characteristic of the vehicle’s electronic suspension and no repair(s) should be attempted for this
concern. This can be verified if the noise is eliminated when either both front wheel suspension accelerometers or
both front strut dampeners are disconnected.

Customer Information
Please communicate to the customer this condition is a normal operating characteristic of their vehicle. It will not
impact the designed performance or reliability of the vehicle. Please share this information with the customer,
including a copy of this message.

Warranty Information
For vehicles repaired under warranty, use:
Labor Operation

Description

Labor Time

8029929

Customer Concern Not Duplicated (CCND) – Suspension

Use Published
Labor
Operation Time