GM Has a Dealer Software Fix for 2027 Cadillac Lyriq Super Cruise Outages

Owners of a 2027 Cadillac Lyriq whose Super Cruise hands-free driving system keeps showing as unavailable now have a known dealer fix. On October 16, 2026, GM updated a preliminary service bulletin that blames the fault on camera-related software and tells technicians to reprogram the SUV's image processing module. The revision added a second diagnostic trouble code to the checklist, B0126, alongside the B1599 code named in the original.

What the bulletin says

Bulletin PIC6663A applies to 2027 Lyriq models equipped with Super Cruise. It also covers the 2027 Chevrolet Tahoe and Suburban and the GMC Yukon and Yukon XL with the same system. The complaint is straightforward: Super Cruise reports that it is not working or not available.

When a dealer scans an affected vehicle, it may find code B1599, subtype 86, stored in the K124 image processing module, a computer that handles camera data for the driver-assistance systems. GM's explanation is a software glitch involving an 8-megapixel camera the bulletin calls a data collection camera. No hardware is replaced.

The repair runs in four steps. The technician contacts GM's technical support line to get updated software for the module, reprograms it, clears the codes, then drives the vehicle under the conditions that triggered the fault to confirm it does not return. If B1599 or B0126 (subtype 49) comes back, the dealer moves on to standard diagnostics. The work is billed to the bumper-to-bumper warranty at GM's published labor time.

GM first released the bulletin on September 17, 2026. Adding B0126 in October suggests technicians were finding the second code on some vehicles with the same symptom.

Not the only reason Super Cruise drops out

Super Cruise relies on several systems, and this bulletin covers only one failure. GM has a separate preliminary bulletin on 2027 models losing their OnStar connection, which also takes Super Cruise offline. The 2027 Lyriq was on that list until October 16, when GM's revision moved it and several other models to another bulletin, 26-NA-282, which was not in NHTSA's public files as of October 23. An OnStar problem tends to show up as a lost Wi-Fi hotspot, a frozen navigation map and a red OnStar button, while the camera software bulletin describes only Super Cruise being unavailable.

Super Cruise also switches off for routine reasons that are not faults: roads outside GM's mapped network, worn lane lines, heavy rain or snow, or a driver who looks away from the road too long. Those situations clear on their own once conditions change. The bulletin problem persists.

Owner brief

What it means for owners

• Who is affected: owners of a 2027 Lyriq with Super Cruise who find it unavailable, drive after drive, on highways where it normally works.
• What to do: book a service visit and mention bulletin PIC6663A. The dealer has to scan the image processing module to confirm B1599 or B0126; basic code readers generally cannot see that module.
• What the dealer does: a software reprogram after a call to GM for the update, followed by a test drive. The bulletin calls for the reprogram at the dealer rather than over the air, so plan for a shop visit.
• Cost: none for a 2027 model, which is well within Cadillac's four-year/50,000-mile bumper-to-bumper warranty.
• If the hotspot and map also fail: say so at check-in. That points to the OnStar issue, a different bulletin and a different repair.
• Recalls: this is a service bulletin, not a recall, and there is no NHTSA campaign for it. Owners can still check their VIN for open recalls at nhtsa.gov/recalls.

Dashbird tip

Record the dealer visit and module reprogram in the service history in Dashbird, so the date and mileage of the fix are on file if Super Cruise starts acting up again.