Workshop Repair and Service Manuals GMC SIERRA

13-08-116-001A Aftermarket ALDL or DLC Interface Devices Causing Multiple Issues - (Mar 22 2013)


Subject:Aftermarket ALDL or DLC Interface Devices Causing Multiple Issues

#13-08-116-001A: Aftermarket ALDL or DLC Interface Devices Causing Multiple Issues - (Mar 22, 2013)

Models: 2006-2014 GM Passenger Cars and Trucks

This bulletin is being revised to add additional possible symptoms, clarify the languageand revise the photos. Please discard Corporate Bulletin Number 13-08-116-001 (Section08 - Body and Accessories).


Customers may comment on various issues with their vehicle related to high or lowspeed data bus traffic. These concerns may be widely varied, but some of the knownissues are listed below.

The information contained in this bulletin is not meant to single out any one deviceor symptom, but to provide additional information that may be useful for diagnosingissues that do not have other diagnostic methods to identify the root cause.

Note:This bulletin is being written with a focus on full size truck and full size van alongwith other fleet vehicles, but could apply to any vehicle.


Known Symptoms (not specific to any one device)

The radio may not shut off after shutting down vehicle.Bus or LAN traffic may stay active leading to a discharged vehicle battery.Problems reprogramming modules either because of interference or the device will notallow the bus to power down.ONSTAR® may lose the ability to provide diagnostic data.Various engine and transmission performance issues with SES light set.Intermittent driveability issues.Reduced power message and codes.Stabilitrak® message and codes.C0561 stored in the EBCM leading to a traction control issue.No high speed LAN communication along with various communication U-codes.Transmission may not shift for one key cycle (TCM in default mode).Erratic gauge readings or flickering displays.SES, MIL or CEL light set and numerous DTC communication codes such as U0100, U0101,U186B and U1862.Diesel power-up devices causing no power in 4WD low range.Erratic electric power steering boost potentially associated with codes U2109, U2107,U2100, B1325, C0000.Service Tire Pressure Monitoring (TPM) system light illuminated.

– Cannot relearn TPM

Specific to Hybrids:Reduced propulsion power message.Service high voltage charging system message.Cause

If nothing else can be identified as the root cause of the issue after normal diagnosticsas found in SI, check for a device plugged into the Assembly Line Diagnostic Link(ALDL) or Data Link Connector (DLC) for tracking and/or maintenance interval scheduling.Monitoring devices, along with other electronic accessories such as aftermarket cruisecontrol, or police speed checking devices (RADAR or LIDAR) may cause one or more ofthe concernslisted above.

Many of the problems described could be caused by an open connection on the HSCANbus. Example: if the device only makes connection with one CAN +, then it will causebus errors and erratic ECU behavior.

These devices may be removed by the customer for use in another vehicle while theirsis brought in for service. The intent of this bulletin is to identify a potentialsource of concerns that do not have other diagnostic methods to identify them.

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