{"id":19820,"date":"2026-04-30T05:00:17","date_gmt":"2026-04-30T09:00:17","guid":{"rendered":"https:\/\/gm-techlink.com\/?p=19820"},"modified":"2026-04-30T15:59:02","modified_gmt":"2026-04-30T19:59:02","slug":"tcsc-top-issues-this-week","status":"publish","type":"post","link":"https:\/\/gm-techlink.com\/?p=19820","title":{"rendered":"TCSC Top Issues This Week"},"content":{"rendered":"

The Techline Customer Support Center (TCSC) is available to help dealerships with diagnostic and programming issues related to Techline Connect (TLC) and the Service Programming System (SPS).<\/p>\n

TCSC has now released its latest tips to help technicians when using Techline Connect applications. (Fig. 1) Look for the latest information on TechLink each week.<\/p>\n

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\"\"Fig. 1<\/strong><\/p>\n

 <\/p>\n

To get the most out of Techline Connect, be sure to review the following items before making a call to TCSC.<\/p>\n

The following information covers current issues and trends facing dealerships as of April 30, 2026.<\/strong><\/p>\n

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WEEKLY ISSUES<\/strong><\/p>\n

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1. NEW<\/span> \u2013 MDI\/Scan Tool Disconnecting in SPS2 Showing Status: Disconnected in TLC<\/strong><\/p>\n

Users may see the MDI\/scan tool disconnect\/reconnect rapidly in SPS2, causing issues with connectivity. GM is aware of this issue and actively investigating.<\/p>\n

To potentially resolve this issue, disconnect the scan tool, reboot the tool, and then reconnect.<\/p>\n

 <\/p>\n

2. Dealer Infrastructure & Security Guidelines (DISG) Exceptions Update<\/strong><\/p>\n

Users may see the following error during Techline Connect installation or launch:<\/p>\n

PDS101:C:\\Users\\<userID>\\sps\\nativelibs\\DllTzSale.dll<\/p>\n

A file not currently included in the DISG exceptions is being flagged by some firewall\/antivirus suites.<\/p>\n

The file is:<\/p>\n

C:\\users\\<userID>\\sps\\nativelibs\\DllTzSale.dll.<\/p>\n

Please make sure your IT support has added this file path to the whitelist exceptions in the firewall\/antivirus suite.<\/p>\n

 <\/p>\n

3. Accessory\/Reconfiguration Programming Window Reduced from 90 Days to 14 Days on VIP Vehicles Only<\/strong><\/p>\n

Starting April 25, 2026, an Accessory\/Reconfiguration added to a VIP Vehicle VIN by TCSC must be reprogrammed by the dealership within 2 weeks (14 days). If programming is not completed by this time, the changes will be reverted, and the dealership will be required to reach out to TCSC and request the update(s) again.<\/p>\n

Note: There will not be an additional charge for changes that are requested again.<\/p>\n

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4. 2021 T1 SUVs (Tahoe, Suburban, Yukon, Escalade) Unable to Complete SDAC (Serial Authentication Data Configuration)<\/strong><\/p>\n

There is currently a known issue affecting 2021 T1 SUVs where the SDAC may fail. The radio, IPC, or Telematics (OnStar) module may be the cause of these failures.<\/p>\n

DO NOT REPLACE THE MODULE. This is a known SPS issue and the current workaround is to disconnect the SDGM X3 connector and re-attempt SDAC. Engineering is aware of this concern and working on a permanent resolution.<\/p>\n

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5. UPDATED<\/span> \u2013 9G8 (DRL\/AHL Disable), SK4 (Engine Idle Timeout), UTQ (Content Theft) and 6N6 (Rear Window Disable) Not Yet Available on 2026 Vehicles<\/strong><\/p>\n

Calibrations for RPOs 9G8, SK4, UTQ and 6N6 are not yet available for model year 2026 vehicles but are planned to be released. However, there is not currently an ETA.<\/p>\n

Note: RPO SK4 calibrations are now available for T1 Trucks (Silverado, Sierra). T1 SUV (Tahoe, Suburban, Yukon, Escalade) is still being worked on.<\/p>\n

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6. 2026 Envision SDM Programming Setting DTCs<\/strong><\/p>\n

There is currently a known issue affecting the SDM modules on 2026 Envision causing DTCs to set after programming. DTCs may include B10B4 or B120C, and B17F0 or B17F2.<\/p>\n

This is being investigated by Engineering. Refer to Bulletin #26-NA-115 for more information.<\/p>\n

 <\/p>\n

7. 2023-2026 HUMMER EV RWQ (37-inch Tire) Calibration Freeze<\/strong><\/p>\n

Currently, TCSC is unable to add 37-inch \u201cRWQ\u201d tires to any 2023-2026 HUMMER EV.<\/p>\n

A resolution for this issue is being developed by Engineering but there is currently no ETA or workaround.<\/p>\n

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COMMON ISSUES AND HELPFUL INFORMATION<\/strong><\/p>\n

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1. 2020 Trax IPC Programming Issue<\/strong><\/p>\n

GM is aware of an issue affecting 2020 Trax models where a replacement IPC may fail with E-4491 and line\/op\/error indicate (X, B0, 85).<\/p>\n

This issue is currently being investigated by Engineering. Please reach out to TCSC if you are experiencing this issue.<\/p>\n

 <\/p>\n

2. Corvette E-9056\/E-9113\/E-9114 Errors with Park Lock Valve PUN Learn<\/strong><\/p>\n

GM has identified an issue with certain Park Lock Valve (PLV) parts on Corvette vehicles. The 21-digit PUN on the package\/box will differ from the PUN on the physical part itself and cause errors if used.<\/p>\n

The 22-digit PUN on the physical part should be used in these cases. It is recommended to notate and\/or screenshot the PUN before installation in case further support is needed from TCSC.<\/p>\n

For more information, refer to Document ID 6970447 in the appropriate Service Information.<\/p>\n

 <\/p>\n

3. 2026 T1 Trucks Governor Changes (9C2\/9B9\/9D7) Require Certain Tire Sizes<\/strong><\/p>\n

Please be aware that for 2026 T1 Trucks, governor changes now require the vehicle to be equipped with certain tire sizes.<\/p>\n

Refer to the Online Order Guide for specifics for your Year\/Make\/Model\/Equipment Group to determine which tires are required for these changes.<\/p>\n

 <\/p>\n

4. T1XX Trucks ECM\/Radio\/IPC Part Missing from SPS2 Part Dropdown<\/strong><\/p>\n

When performing IPC Graphics programming, Radio USB, or ECM programming, you may be prompted in SPS2 to select \u201cService Hardware.\u201d<\/strong> However, this is misleading.<\/p>\n