TCSC Top Issues This Week

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).

TCSC has now released their latest tips to help technicians when using Techline Connect applications. (Fig. 1) Look for the latest tips on TechLink each week.

 

Fig. 1

 

To get the most out of Techline Connect, be sure to review the following items before making a call to the TCSC.

The following information covers current issues and trends facing dealerships as of March 18, 2026.

 

WEEKLY ISSUES

 

1. UPDATED – FCM Learn Fails at 94%, DTC U3000 Set, Service Front Camera, Service Forward Collision or Forward Collision Unavailable Displayed on Cluster

#PIT6473D has been updated for these issues.

On MY2022 Only (Built with RPO: J22), issues may have been caused by incorrectly released calibrations. Engineering is working on re-releasing the correct calibrations. Do not contact TAC or TCSC about this issue. The PI will be updated once the calibrations have been corrected.

Note: The FCM has been removed from Supported Controllers in SPS2.

 

2. UPDATED – 2026 Envision SDM Programming Setting DTCs

There is currently a known issue affecting the SDM modules on 2026 Envision causing DTCs to set after programming. DTCs can include B10B4 or B120C, and B17F0 or B17F2.

This is being investigated by Engineering and a PI/Bulletin is being developed to address this issue. As a temporary workaround, Techline can be contacted to inquire with Engineering for a VCI to resolve this concern.

Note: The DTC reference documents in SI have been updated to check the EPC for the correct H/W part number(s).

 

3. NEW – 2026 T1 Trucks Governor Changes (9C2/9B9/9D7) Require Certain Tire Sizes

Please be aware that for MY2026 T1 trucks that governor changes now require the vehicle to be equipped with certain tire sizes.

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

 

4. Chevrolet Express MY2015+ SOSM E-4399 Issue

GM is aware of a known issue where programming current/replacement SOSM modules (Left/Right) will cause an E-4399 error in SPS2, despite the modules having communication.

Please reach out to TCSC for a VCI to correct this concern.

 

5. 2020 Trax IPC Programming Issue

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).

This issue is currently being investigated by Engineering. Please reach out to TCSC if you are experiencing this issue.

 

6. 2023-2026 HUMMER EV RWQ (37-inch Tire) Calibration Freeze

Currently, TCSC is unable to add 37-inch “RWQ” tires to any 2023-2026 HUMMER EV.

A resolution for this issue is being developed by Engineering but there is currently no ETA or workaround.

 

7. 9G8 (DRL/AHL Disable) and SK4 (Engine Idle Timeout) are NOT Yet Available on 2026 Vehicles

Calibrations for 9G8 and SK4 are not yet available but are planned to be released for model year 2026 vehicles. However, we do not currently have an ETA.

 

8. 2025 Blazer EV Radio USB File Transfer Option Missing

For 2025 Blazers built with an RPO IVE Radio, the USB Programming option has been removed from Radio programming. No USB update is required for replacement parts. Refer to #PIC6641A for more information.

 

9. Corvette E-9056/E-9113/E-9114 Errors with Park Lock Valve PUN Learn.

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.

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.

For more information, refer to Document ID 6970447 in the appropriate Service Information.

 

10. Front-View Camera Programming or Camera Learn Issues Specific to 2024 Colorado and Canyon (ZR2)

There is currently a known issue with the Front-View Camera involving ONLY 2024 Colorado/Canyon built with ZR2 and UHY, and without UWI, UKW, or ULV.

The Front-View Camera may fail to program or set loss of communication codes such as DTC U0265. The Camera Learn also may fail in GDS2 with various errors.

A VCI is required to correct this problem. Please reach out to TCSC for this fix.

 

COMMON ISSUES AND HELPFUL INFORMATION

 

1. T1XX Trucks ECM/Radio/IPC Part Missing from SPS2 Part Dropdown

When performing IPC Graphics programming, Radio USB, or ECM programming, you may be prompted in SPS2 to select “Service Hardware.” However, this is misleading.

For IPC Graphics programming, use the “Boot Software Part Number 1” found in GDS2 under Identification Information.

Similarly, for the Radio USB Programming, use the “Calibration Part Number 1” (also may be called “Application Part Number 1”) found in GDS2 under Identification Information.

Additionally, for the ECM, use the “Calibration Part Number 1” (also may be called “Software Module Part Number 1”) found in GDS2 under Identification Information.

 

2. SPS Info Location

Several requests have been made regarding where SPS Info is currently located. SPS Info is available for calibration lookup and is located on its own tab within the Techline Connect launch page through Global Connect. (Fig. 2)

Fig. 2

 

3. 2024+ Silverado 2500HD/3500HD and Sierra 2500HD/3500HD Adding ZW9 (Bed Delete) Support

Engineering has confirmed that there are not any compatible calibrations that support both RPO ZW9 (Bed Delete) and RPO UV2 (HD Surround Vision Camera).

RPO ZW9 cannot be added to vehicles with RPO UV2 regardless of trim level.

Note: RPO ZW9 is supported for both long and short bed models and is also supported regardless of 17/18/20/22-inch tire sizes.

Refer to the GM Vehicle Order Guide for details, including equipment groups supported (e.g., 1WT, 1LT).

 

4. Bulletin #24-NA-098: SPS Best Practices and Programming Error Troubleshooting

Document ID: 6662319 has been published to assist with common programming errors, descriptions and recommended helpful/general troubleshooting for SPS errors. Please refer to this page if you encounter a programming error within SPS2/TLC.

 

5. TLC Restricted Access

The following message may be seen when attempting to access Techline Connect. (Fig. 3)

Fig. 3

 

The message indicates the current ID is blocked from accessing Global Connect. This can be for a multitude of reasons but typically is due to a counterfeit MDI device.

To unblock the account, reach out to TCSC via Dealer Case Management (DCM) with the following information:

• User ID in Global Connect
• Email of User
• First and Last Name of User
• BAC/Dealer Code and Name of Dealership

TCSC will be able to reach out to the Cybersecurity team that will be able to determine the cause of the block and may be able to unblock the account. In the case of a counterfeit MDI, the counterfeit tool must be destroyed, and a legitimate Bosch device must be used to ensure the ID is not blocked again. Repeat offenders may not be unblocked from access.

 

6. E-9111 or E-9113/E-9114 TCM/MCVM Operation Errors

An E-9111 or E-9113/E-9114 error may occur when programming the TCM, or after replacing the transmission assembly/valve body, and entering the TUN/PUN under MCVM Operations in SPS2.

The error is caused by a mismatch in data between the vehicle’s TUN/PUN and the TUN/PUN uploaded in the GM database. Please ensure the complete TUN/PUN number is entered correctly, and that the TUN/PUN is in capital letters. Double check that the number zero (0) is not a letter “O” and that there are not any typos or extra characters.

If the TUN/PUN is correct, open a DCM case with TCSC and attach a clear picture of the replacement TUN/PUN in the case, as TCSC will require these to work with Engineering and have the issue addressed.

If you are receiving these errors via programming and the TUN/PUN was not replaced, TCSC may still require the TUN number.

 

7. Downsizing of Tires is Not Supported on T1 Full-Size Trucks and SUVs

Please be advised that downsizing tires of any kind is not supported on any T1 series vehicle from 2021 – Current. This includes full-size trucks (Silverado, Sierra) as well as SUVs (Tahoe, Suburban, Yukon, Escalade).

 

8. Approach/Exit Lighting Condition – MY2026 Silverado EVs Built with RPO SFW

 GM has identified a condition where the backup alarm makes noise when approach/exit lighting is activated, such as when locking/unlocking the doors.

The only fix for this issue is to disable the approach/exit lighting through the Settings menu on the infotainment display.

To disable the lighting in the Settings menu, go to Settings > Vehicle > Lighting > Vehicle Locator and toggle Lights [OFF] & Exit Lighting [OFF].

 

How to Contact TCSC

• U.S. ONLY: Assistance can be provided by using the CX Connect portal on Global Connect. If additional support is needed once the CX Connect case is created, contact TCSC at 1-800-828-6860. For U.S. only, a case is required for phone support.
• Canada: Contact TCSC at 1-800-828-6860 (English) or 1-800-503-3222 (French).
• All other regions: Contact your regional Technical Assistance team for Global Techline Support.

 

– Thanks to the Techline team