PIC5428D

File in Section:
Service Bulletin
Bulletin No.:
Date:
PIC5428D
March, 2013
PRELIMINARY INFORMATION
Subject:
EBCM Wheel Speed Sensor Diagnostic Aid for ABS Message - Click Or Ratchet Noise Service Traction Message - Service Stabilitrak Message
Models:
2008-2013 Buick Enclave
2010-2013 Buick LaCrosse
2011-2013 Buick Regal
2012-2013 Buick Verano
2008-2013 Cadillac CTS/CTS-V
2010-2013 Cadillac CTS Wagon
2011 2013 Cadillac CTS/CTS-V Coupe
2010-2013 Cadillac SRX
2013 Cadillac XTS - FWD Models (rear non-driven wheel bearings only)
2010-2013 Chevrolet Camaro
2011-2013 Chevrolet Camaro Convertible
2009-2012 Chevrolet Colorado
2011-2013 Chevrolet Cruze, Volt
2010-2013 Chevrolet Equinox
2014 Chevrolet Impala (New Body Style)
2013 Chevrolet Malibu
2009-2013 Chevrolet Traverse
2009-2012 GMC Canyon
2007-2013 GMC Acadia
2010-2013 GMC Terrain
2007-2010 Saturn Outlook
with any of the following DTCs or Symptom codes C0035 C0040 C0045 C0050 with
symptom bytes 18 5A 0F
This PI was superseded to update model list, model years, and condition/concern. Please
discard PIC5428C.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Some customers may comment on any of the following conditions:
• ABS, Service Traction Control System, and/or Service Stabilitrak telltale lights are on. During initial scan for
EBCM module diagnostic codes you may find one or more of the following DTCs C0035-C0050 with specifically
symptom bytes 18, 5A, 0F.
• A brief and intermittent noise, click, ratchet, grind, or ABS pump motor noises typically heard from the inside of
the vehicle at parking lot speeds.
• A flashing Traction Control or Stabilitrak telltale at low speeds.
The latter two conditions correspond with no reported EBCM / ABS / Stability DTCs set current or history.
These conditions may be caused by single or multiple pieces of ferrous metallic debris stuck to the wheel speed
sensor magnetic encoder ring. This magnetic encoder ring is now part of the inboard bearing hub assembly.
Background Information:
2596034
1. Wheel Speed Sensor Magnetic Encoder Ring
North and South Poles are shown
NEW BEARING DESIGN
2596032
1. Magnetic Encoder Ring
Some new model vehicles today have begun to use a different type of wheel speed sensor encoder ring or tone
wheel. Instead of a traditional mechanical type tooth tone wheel, the wheel speed sensor tone wheel is now made of
a magnetized nitrile rubber ring, typically brown in color. This magnetic encoder consists of multiple North and South
Pole pairs surrounding the outer circumference. When this magnetic encoder ring rotates and passes by the wheel
speed sensor head; it generates a sign wave in the wheel speed sensor. The wheel speed sensor converts an
analog signal to a digital square wave, and typical digital signal values switch between 7mA (Low) and 14mA (High)
DC current.
Recommendation/Instructions
Inspect and clean debris from the Encoder Ring.
Inspection and Cleaning Procedure:
Below inspection and cleaning procedure is supporting information to the SI wheel speed sensor diagnostic
mechanical fault table. In most cases the DTCs C0035-C0050 with symptom bytes 18, 5A, 0F can be repaired by
removing and/or cleaning any accumulated debris on the magnetic encoder ring; which is located on the inboard
side of the bearing hub.
Important: Most repairs can be performed without any replacement of the bearing hub assembly or wheel speed
sensor.
Caution: Take care not to damage the bearing outer seal when brushing and/or cleaning the magnetic encoder
debris.
Do not use any type of magnetic tool to remove the debris from the bearing magnetic encoder; an external magnet
can damage the encoder.
BEFORE CLEANING
2596037
1. Sample Debris
1. Based on the specific EBCM module Wheel Speed Sensor DTC code; inspect the appropriate corner magnetic
encoder ring for possible debris.
– C0035 Left Front Corner
– C0040 Right Front Corner
– C0045 Left Rear Corner
– C0050 Right Rear Corner
2. If debris is found, perform the following cleaning recommendations.
Important: To properly clean the magnetic encoder ring, some applications may require removal of the bearing/hub
assembly. Refer to the specific Wheel Bearing and Hub Replacement procedure in SI.
2.1. Gently using a dry nylon soft bristle brush, remove the foreign debris off the magnetic encoder ring. If
debris was removed, proceed to step 3.
2.2. If debris still remains, wash the encoder ring using a mild soap detergent and wipe dry.
AFTER CLEANING
2596035
3. Connect a scan tool to the vehicle. Turn ON the ignition. Clear the DTCs.
4. Perform vehicle diagnostic repair verification procedure for DTC: C0035-C0050. Refer to SI.
Warranty Information
For vehicles repaired under warranty use:
Labor
Operation
* H9757
* H9758
Description
Inspect and Clean Debris From
Front Wheel Speed Sensor Encoder
Ring (One Side)
Inspect and Clean Debris From Rear
Wheel Speed Sensor Encoder Ring
(One Side)
Vehicle(s) Involved
Labor Time
Camaro, CTS (RWD), Colorado (RWD),
Canyon (RWD)
0.4 hr
SRX, Volt
0.7 hr
CTS (AWD), Acadia, Enclave, Outlook, Traverse,
Equinox, Terrain, Cruze, Verano
1.0 hrs
LaCrosse, Regal
0.9 hr
Malibu
0.8 hr
Impala, XTS
1.6 hr
Colorado (4WD), Canyon (4WD)
1.9 hr
Acadia (FWD), Enclave (FWD), Outlook (FWD),
Traverse (FWD), SRX (FWD), LaCrosse (FWD),
Regal (FWD), Equinox (FWD), Terrain (FWD),
Malibu, Impala, XTS (FWD)
0.4 hr
Camaro, CTS, Equinox (AWD), Terrain (AWD)
0.9 hr
SRX (AWD)
1.1 hrs
LaCrosse (AWD), Regal (AWD)
2.1 hrs
Acadia (AWD), Enclave (AWD), Outlook (AWD),
Traverse (AWD)
1.0 hrs
Volt
0.8 hr
Cruze, Verano
0.6 hr
XTS (AWD)
1.4 hr
*This is a unique labor operation number for PI use only. This will not be published in the Labor Time Guide.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.