U0197 on Chevrolet: How to Diagnose & Fix
Lost Communication With Telephone Control Module
1 Chevrolet model · 1 documented issue · 1 critical
U0197 on Chevrolet by model: symptoms, diagnosis and fix
The telematics control module — the OnStar unit — fails on a large scale across the redesigned Equinox and the Equinox EV. It is the single largest complaint cluster in NHTSA's electrical-system category for the 2025 Equinox. When the module fails it stops sleeping and continuously draws current, flattening the 12-volt battery; owners report waking to a dead vehicle and, in the worst cases, the car shutting down mid-drive, with one report of the battery measured at 0.03 volts. The failure simultaneously disables every OnStar-dependent safety and convenience function: Automatic Crash Response, emergency calling, GPS position (which can read miles off), remote start, remote lock/unlock through the myChevrolet app, and over-the-air update delivery. Replacement modules have been on nationwide backorder for extended periods, with owners reporting month-plus waits and at least one case where the replacement module was itself faulty. GM has not issued a recall or a public service bulletin for the defect.
Common Symptoms
- Dead 12V battery repeatedly, especially after the car sits a day or two
- Vehicle shuts down or loses power while driving
- OnStar unavailable / 'Service OnStar' message
- Remote start and remote lock/unlock stop working in the myChevrolet app
- GPS location wrong by miles
- Automatic Crash Response and emergency calling inoperative
- Dealer says the telematics module is on national backorder
How to Fix
Have the dealer perform a parasitic draw test with the telematics module fused out to confirm the module is the current draw before replacing the 12-volt battery — repeatedly replacing a battery that a failed TCM is killing wastes money and does not fix the fault. Confirm the diagnosis by checking whether OnStar services, app remote commands and GPS position are all dead at once, which points at the module rather than the battery. Open a case with GM Customer Assistance to get a parts-priority escalation and a loaner while the module is on backorder, and keep every repair order — the combination of a documented safety-system loss and a long parts wait is the basis for a state lemon-law or Magnuson-Moss claim. As a stopgap, a battery tender will keep the vehicle startable but does not restore crash response.
Sources for this issue (3)
U0197 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U0197 mean on a Chevrolet?
U0197 stands for "Lost Communication With Telephone Control Module." A generic network code that sets when a module loses the expected data messages from the Telephone Control Module, which manages hands-free/Bluetooth phone functions. Set after the module fails to respond for a calibrated period. On Chevrolet it is documented across 1 model: Equinox.
What are the most common causes of U0197?
The most common causes of U0197 are: Loss of power or ground to the telephone control module, Open, shorted, or corroded bus wiring, Loose or corroded connector, Blown fuse, Failed telephone control module. The specific cause varies by vehicle.
How much does it cost to fix U0197 on a Chevrolet?
Repair costs vary widely with the root cause and Chevrolet model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.