OnStar is one of GM's most valued features — but when it stops working it is a real headache. Whether the OnStar button does nothing, the light has gone red, remote commands have stopped, or the system went offline after a battery replacement, this guide covers the common causes and what GM has actually published about them.
Read the primary documents yourself: GM Service Update N262547330-01, released 7 May 2026 (PDF) — the current revision, with the full vehicle list and service procedure. The original April 2026 release is also public. Both hosted by NHTSA as manufacturer communications.
Updates and corrections.
- Service Update N262547330 was revised on 7 May 2026, adding vehicles and updating the procedure. An earlier version of this page listed a partial and now-outdated set of models. The current list is below.
- The 3G section contradicted itself, giving 2010–2018 in one place and 2010–2015 in another. GM moved to 4G LTE around the 2015 model year, so the vehicles affected by the 3G shutdown are roughly 2010–2014.
- The claim that emergency calling stays free without a subscription has been removed. We could not substantiate it, and it is not a safe thing to be wrong about — if you are relying on Automatic Crash Response, verify your own plan status rather than assuming.
How OnStar Works
OnStar depends on a telematics module — GM calls it the Telematic Control Module in its service bulletins, and it also appears as the Communication Interface Module, telematics interface module or TCU depending on the document. It contains the cellular transceiver and GPS receiver, and it handles:
- Emergency and roadside assistance calls, including Automatic Crash Response
- Remote start, lock and unlock through the owner app
- Vehicle diagnostics and monthly reports
- The Wi-Fi hotspot
- Stolen vehicle assistance and location services
A note on the abbreviation. You will see this module called the "TCM" in places, but TCM conventionally means Transmission Control Module, and confusing the two sends you to entirely the wrong diagnostics. We spell out "telematics module" on this page for that reason.
GM Service Update N262547330 — Telematics Module Reprogramming
If you have a recent GM vehicle with OnStar problems, start here.
GM's bulletin describes the condition plainly: certain vehicles "may have a condition in which the Telematic Control Module may enter an unrecoverable state." In practice that disables OnStar, remote commands and app connectivity.
The correction is to reprogram the module — and GM adds a detail that explains why some owners make more than one trip:
The module may be several software versions behind and could take multiple programming events to bring it to the latest software level.
GM instructs technicians to keep programming until the same-calibration screen appears, confirming the module is current. If your dealer reprograms it once and the fault returns, that is a known pattern rather than a new problem.
Vehicles covered by the current revision
From the 7 May 2026 revision:
- 2025–2026 Buick Enclave
- 2025 Cadillac CELESTIQ
- 2025–2026 Cadillac CT5
- 2024–2026 Cadillac LYRIQ
- 2025–2026 Cadillac OPTIQ
- 2026 Cadillac VISTIQ
- 2024–2025 Cadillac XT4
- 2024–2026 Chevrolet Blazer EV
- 2025–2026 Chevrolet BrightDrop 400 and 600
- 2026 Chevrolet Corvette
- 2025–2026 Chevrolet Equinox
- 2024–2026 Chevrolet Equinox EV
- 2025–2026 Chevrolet Silverado EV
- 2025–2026 Chevrolet Traverse
- 2025–2026 GMC Acadia
- 2025–2026 GMC Sierra EV
- 2025–2026 GMC Terrain
Being on this list does not mean your VIN is included. A dealer check against Investigate Vehicle History is the only way to confirm.
Three practical points from the bulletin
It may arrive over the air. Owners who have accepted the applicable terms and conditions may receive the update wirelessly, with no dealer visit. Worth checking your software update settings before booking anything.
EVs need a certified dealer. GM restricts this work on electric vehicles to authorised EV dealers with trained technicians. Confirm when you schedule rather than on arrival.
An OnStar call is part of the procedure. GM's steps require pressing the OnStar button to place a test call after reprogramming, so the advisor can verify the module is properly provisioned. If your dealer returns the vehicle without that step, the job is not finished — and an unverified module is a common reason the problem appears to come back.
This is a service update, not a recall, which means dealers complete it during routine visits rather than contacting owners urgently. You may need to raise it yourself.
Other Common OnStar Problems
Red light on the OnStar button
The most reported symptom, and often the first sign of a telematics module fault. Causes include loss of network connection, the module entering the unrecoverable state described above, a power supply or fuse problem, or disruption following a battery replacement.
OnStar went offline after a battery replacement
Very common. When the battery is disconnected or fully discharged, the module can lose configuration or hang.
- Drive normally for a while somewhere with decent cellular coverage — some modules re-establish their connection on their own
- Avoid judging it from an underground car park
- Call OnStar and ask them to re-provision the module remotely
App and remote commands not working
The button works and reaches an advisor, but the app reports the vehicle unavailable.
- Check subscription status — remote features generally require an active plan
- Sign out and back in, or reinstall the app
- Confirm the vehicle is still linked to your account
- Ask OnStar to re-push provisioning
Wi-Fi hotspot dropped
Usually a data plan that has lapsed or hit its cap, or a carrier network problem. If the plan is active and the hotspot is still missing, the module may need reprogramming.
Poor voice quality on OnStar calls
Advisors struggling to hear you points at the microphone rather than the module — commonly near the mirror base or overhead console, and vulnerable to a loose or corroded connector. Weak local cellular coverage produces the same complaint.
Subscriptions — Check Rather Than Assume
After the trial included with a new vehicle, most OnStar features require an active plan, and GM has restructured its plans and their names more than once.
Rather than reproduce a plan list that may already be out of date, check your own status directly — through your OnStar account, the owner app, or by pressing the button and asking the advisor what your vehicle currently has.
This matters most for emergency services. If you are counting on Automatic Crash Response being there after a collision, confirm it is active on your vehicle today. That is a one-minute check and not something to take on trust from any article, including this one.
Older GM Vehicles: the 3G Shutdown
If you have an older GM vehicle whose OnStar simply stopped working and never came back, the cause is likely the 3G cellular network shutdown completed by US carriers in 2022. Those modules had no path to the newer networks.
This affects roughly 2010–2014 vehicles. GM moved to 4G LTE hardware around the 2015 model year, so a 2015 or newer vehicle losing OnStar almost certainly has a different problem worth diagnosing.
GM ran hardware upgrade programmes for some affected vehicles. Whether yours qualifies is a question for OnStar with your VIN — for many older vehicles, connectivity is simply not recoverable without new hardware.
Troubleshooting Checklist
- Check your subscription status
- Press the OnStar button — do you reach an advisor at all?
- Try it somewhere with strong cellular coverage
- Drive normally for a day or two after any battery work before concluding it is broken
- Update or reinstall the owner app and sign in again
- Check whether your vehicle has pending over-the-air updates
- Ask a dealer whether Service Update N262547330 applies to your VIN
- Call OnStar and ask for remote re-provisioning before booking a visit
- If a dealer reprograms the module, make sure the verification call is done before you leave
Frequently Asked Questions
Why is my OnStar light red?
A red light usually means the telematics module has lost its connection or entered a fault state. On recent GM vehicles this is frequently the condition covered by Service Update N262547330, where the module can enter what GM calls an unrecoverable state. Ask a dealer to check whether that update applies to your VIN before paying for diagnosis.
What is GM Service Update N262547330?
A service update, not a recall, covering a wide range of 2024 to 2026 Buick, Cadillac, Chevrolet and GMC vehicles where the Telematic Control Module may enter an unrecoverable state, disabling OnStar, remote commands and app features. The remedy is reprogramming the module. It was revised on 7 May 2026 to add vehicles and update the procedure.
Why did my dealer have to reprogram the module more than once?
Because GM's own bulletin says to. The module may be several software versions behind, and GM instructs technicians to keep running the programming until the same-calibration screen confirms it has reached the latest level. Multiple programming events in one visit are expected, not a sign of incompetence.
Can the fix be done over the air?
Sometimes. GM states that owners who have accepted the applicable terms and conditions may receive the update wirelessly without visiting a dealer. Check your vehicle's software update settings before booking an appointment. Electric vehicles that do need a dealer visit must go to a certified EV dealer.
My OnStar stopped after a battery replacement. Is it broken?
Not necessarily. Losing power can leave the telematics module hung or unprovisioned. Drive normally for a day or two in areas with decent coverage, then call OnStar and ask them to re-provision the module remotely. That resolves it often enough to be worth trying before a dealer visit.
Why did OnStar stop working on my older GM vehicle?
Most likely the 3G network shutdown completed by US carriers in 2022, which stranded telematics hardware in roughly 2010 to 2014 vehicles. GM moved to 4G LTE around the 2015 model year. If your vehicle is 2015 or newer, the 3G sunset is not your problem and it is worth diagnosing properly.
Do I still have emergency services without a subscription?
Do not assume so. Most OnStar features require an active plan, and GM has changed its plan structure more than once. If you are relying on Automatic Crash Response, confirm it is currently active on your vehicle through your account, the app, or by pressing the button and asking the advisor. An earlier version of this page stated emergency calling remained free without a subscription; we could not substantiate that and have removed it.
What should I make sure the dealer does?
Confirm the module reached the latest calibration, and confirm the OnStar verification call was made. GM's procedure requires pressing the OnStar button after reprogramming so an advisor can verify the module is properly provisioned. Skipping that step is a common reason the problem appears to return.
A Note on Sourcing
The Service Update N262547330 details — the condition, the correction, the vehicle list, the multiple-programming instruction, the over-the-air provision, the EV dealer restriction and the required OnStar verification call — come from GM's bulletin N262547330-01 of 7 May 2026, which we read directly. The original April 2026 release is linked for reference.
Three things changed in this revision. The vehicle list was outdated and has been replaced with the current one. The 3G section contradicted itself on model years and now gives roughly 2010–2014, consistent with GM's move to 4G LTE around 2015. And a claim that emergency calling remains free without a subscription was removed as unsubstantiated.
Subscription plan names and contents change, so this page deliberately does not reproduce a plan list. Check your own account instead.
The troubleshooting steps are ours, based on service experience rather than GM procedure.
Bulletins get revised. This one was revised within a month of release. Your dealer's check against Investigate Vehicle History is authoritative for your VIN.
Related GM Service Guides
- CSP N252501791: Telematic Control Module Reprogramming (2023 Lyriq, Colorado, Canyon)
- CSP N262545571: Infotainment System Software Update
- GM Check Engine Light Codes
- The Complete GM & Chevrolet Owner's Guide
Shop Related Parts & Accessories
Related accessories — note that none of these fix a telematics module fault, which is dealer work:
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Buture Beta04 Heavy Duty Car Jump Starter 6000A — $109.99. A flat battery is a common trigger for telematics dropouts, so avoiding a full discharge helps.
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GPS Sat Nav Update SD Card — $41.07. For onboard map updates on Cadillac models with SD-based navigation.
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Silicone Key Fob Case Cover — $14.29