Monthly Archives: May 2015

Damaged Suspension Components Due to Vehicle Modifications

There may be some various handling or vehicle dynamics concerns, noises from the suspension or underbody, or issues related to damaged suspension components on some 2007-2013 Escalade EXT, Avalanche; 2007-2015 Escalade models, Silverado, Suburban, Tahoe, Sierra models and Yukon models. … Continue reading

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Safety Alert Seat Cushion Discomfort

When sitting in the driver’s seat on some 2015 Escalade models, Silverado, Suburban, Tahoe, Sierra, Yukon Models; 2014 Silverado 1500 and Sierra 1500 models equipped with the Driver Alert Package (RPO Y65), it may be possible to feel the left … Continue reading

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Duramax Diesel Head Gasket Replacement

The following are recommendations and best practices to follow during Duramax diesel cylinder head service or gasket replacement on 2001-2015 Express, Silverado, Savana and Sierra models equipped with the Duramax diesel engine (RPO LB7, LBZ, LGH, LLY, LML, LMM).   … Continue reading

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Comfort Open/Remote Venting Windows

On some 2013-2014 XTS and 2014 CTS Sedan (VIN A) models, the windows may roll down when this operation is not desired after using the Remote Keyless Entry (RKE) transmitter (key fob). Some owners may have found all windows were … Continue reading

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Unseated Pins in the Transmission Connector

On some 2006-2011 STS; 2007-2009 SRX; 2008-2014 CTS (VIN D) built prior to May 1, 2014; 2013-2014 ATS built prior to May 1, 2014; and 2014 CTS Sedan (VIN A) built prior to May 1, 2014, equipped with a 6-speed … Continue reading

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Mobile Device Wireless Charging Update

The Wireless Charging system for smartphone is an inductively coupled means for wirelessly charging mobile devices in the vehicle; no cables necessary.   It’s available on 2015-2016 ATS, CTS sedan, Tahoe (Fig. 4), Suburban, Yukon models, and Escalade models. It … Continue reading

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Service Information Circuit/System Verification Changes

Based on feedback from GM field service engineers, the Technical Assistance Center (TAC), GM service trainers and dealership service technicians, there have been a few cases documenting the difficulty of isolating an issue using the diagnostic procedure Circuit/System Testing category … Continue reading

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The Beginnings of a New Bulletin

Things change fast in the automotive world. Products and components may require repairs that need to be made immediately or service procedures need to be updated. So how are these conditions found? And how does the word get out to … Continue reading

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CH-51450-A Oscilloscope Diagnostic Kit with NVH Released as Essential Tool

GM has begun shipping the CH-51450-A NVH Kit as an essential diagnostic tool to all GM dealerships. Shipments will continue through July 2015.   The CH-51450 NVH Kit (Fig. 1) was first released last year as the replacement of the … Continue reading

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GDS 2 Update Enables Users to “Contact Us”

The latest GDS 2 software update (14.0.x) recently released provides users with a new way to provide feedback or ask questions about the diagnostic software application.   Feedback Options   After updating GDS 2 to 14.0.x, users can click the … Continue reading

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Loss of Isolation Testing on High Voltage Systems

The following technical information is intended to inform professional service technicians about Loss of Isolation testing on high-voltage vehicle systems.   The high voltage system in the Volt (Fig. 7), ELR and Spark EV is isolated from the vehicle. It … Continue reading

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OnStar and XM Antenna Malfunctions

On some 2015 Escalade, Silverado, Suburban, Tahoe, Sierra and Yukon models equipped with a high-frequency painted antenna assembly (Fig. 12), one or more of the following symptoms may be present: • Visible water leak or signs of water intrusion from … Continue reading

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Water Leak Diagnostic Tips

A water leak into the cab, water staining of the headliner or water on the floor may be found on some 2015 Colorado or Canyon models.   To diagnose these water leak conditions, follow the appropriate procedures in the Service … Continue reading

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Full-Size Truck Instrument Panel Cluster Replacement

If the instrument panel cluster (IPC) (Fig. 13), which is on parts restriction, requires replacement on 2014 Silverado 1500, Sierra 1500; 2015 Silverado, Suburban, Tahoe, Sierra and Yukon models, authorization must be received from the Techline Customer Support Center (TCSC) … Continue reading

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Increased Seat Motor Noise

There may be an increased power seat motor noise when moving the driver or passenger seat forward or backward using the Easy Entry power seat switch or the power seat switch on the 2015 ATS coupe and 2014-2015 ELR compared … Continue reading

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Special Edition Paint Codes

Dealerships may have difficulty locating the correct paint code for the following special edition vehicle models: 2003-2005 Deville – Mary Kay Edition 2003–2004 Seville – Mary Kay Edition 2004 XLR – Neiman Marcus Edition 2006–2011 DTS – Mary Kay Edition … Continue reading

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Service Know-How

10215.05D – Emerging Issues May 14, 2014   To view Emerging Issues seminars: • Log in to www.centerlearning.com –   Select Resources > Service Know-How/TECHAssist > Emerging Issues > Searchable Streaming Video; or –   Select Catalog to search for the course … Continue reading

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Bulletin Review – April 2014

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