Aftermarket ALDL or DLC Interface Devices Causing

Aftermarket ALDL or DLC Interface Devices Causing
Aftermarket ALDL or DLC Interface Devices
Causing Multiple Issues
2006-2013 GM Passenger Cars and Trucks
Customers may comment on various issues with their vehicle related to high or low speed data bus
traffic. These concerns may be widely varied, but some of the known issues are listed below.
This bulletin is being issued with a focus on full-size trucks and full-size vans along with other fleet
vehicles, but may apply to any vehicle.
Known Symptoms:
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 not allow
the bus to power down.
ONSTAR® may lose the ability to provide diagnostic data.
Various engine and transmission performance issues with SES light ON.
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.
Service Tire Pressure Monitoring (TPM) system light illuminated.
Cannot relearn TPM
Specific to Hybrids:
Reduced propulsion power message.
Service high voltage charging system message.
If nothing else can be identified as the root cause of the issue, check for a device plugged into the
Assembly Line Diagnostic Link (ALDL) or Data Link Connector (DLC) for tracking and/or
maintenance interval scheduling. Insurance monitoring devices, along with other electronic
accessories such as aftermarket cruise control, or police speed checking devices (RADAR or
LIDAR) may cause one or more of the concerns listed above.
Many of the problems described could be caused by an open connection on the HSCAN bus.
Example: if the device only makes connection with one CAN +, then it will cause bus errors and
erratic ECU behavior.
These devices may be removed by the customer for use in another vehicle while theirs is brought in
for service. The intent of this bulletin is to identify a potential source of concerns that do not have
other diagnostic methods to identify them. The examples below illustrate some of the devices
Device W/Secondary DLC Connector
This device has another DLC connector on it. The rest of the harness along with the device can be
placed out of sight hidden from the technician, who may not notice the diagnostic connector is not in
the factory location.
Pedal Mounted Aftermarket Cruise Control Interface
Aftermarket Cruise Control Interface at ALDL
Aftermarket Cruise Control Switch
Insurance Monitoring Device
Fleet Tracking Device Interface (May Include Rental and Lease Vehicles)
Fleet Tracking Device Plugged Into the DLC
If the device is available, attempt to duplicate the condition, then remove the device to determine if
the condition is eliminated. If confirmed, inform the customer of the issue and that they need to work
with the supplier of the device for further resolution.
If the condition is not eliminated, continue with Service Information Diagnostics.
Parts Information
There should not be any parts required. If parts appear to have been damaged by the device or the
installation of the device, this would not be a defect covered under the New Vehicle Limited
Warranty. For more information on Non-General Motors Parts & Equipment and Original
Equipment Alterations, please refer to Article of the Service Policies and Procedures
Manual. The repair order must be documented correctly stating factual information on what
alteration or product was identified on the vehicle.
Warranty Information
If ALDL interface devices are suspected as the root cause for a customer's concerns submit a claim
using the Z1111 labor operation to document the concern as detailed in bulletin “Warranty
Administration - Labor Operation Z1111 - Suspected Tampering or Vehicle Modifications 09-00-89016B including submitting the claim under the appropriate labor operation and Customer
Satisfaction selection in Global Warranty Management.
If a claim is submitted to GM, follow all existing guidelines within the Policy and Procedures and
Claims Processing Manual, Administrative Messages, Bulletins or any other communication format.
Labor Operation
*This is a unique labor operation for bulletin use only. It will not be
published in the Labor Time Guide.
0.2 hr
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF