Were stored, pending, or historical low-voltage, gateway, body-control, charging, or BMS codes found?

Request this answer in writing from the service advisor before authorizing repair work. The full playbook covers documentation procedures and post-service verification steps.

Was parasitic draw or module wake/sleep testing performed?

Request this answer in writing from the service advisor before authorizing repair work. The full playbook covers documentation procedures and post-service verification steps.

What software versions were installed before and after service?

Request this answer in writing from the service advisor before authorizing repair work. The full playbook covers documentation procedures and post-service verification steps.

Has VIN [VIN] been checked for all applicable Ultium and Lyriq campaigns?

Request this answer in writing from the service advisor before authorizing repair work. The full playbook covers documentation procedures and post-service verification steps.

app / playbooks / Cadillac Lyriq — battery warning

elevated severity battery warning 2023—2025 dealer

Cadillac Lyriq battery warning (2023—2025)

Cadillac Lyriq · 2023—2025 · all trims

Diagnostic code reference

Reading codes off a Cadillac Lyriq service invoice? Look them up in our OBD-II DTC database →

Reported symptoms

12V (the vehicle's low-voltage accessory battery system) battery repeatedly discharges or vehicle fails to wake/start
Vehicle reports electrical-system, charging, or accessory-power warnings
myCadillac app reports vehicle offline or incorrect status
Displays, locks, lighting, or infotainment behave inconsistently before low-voltage event
Vehicle becomes disabled after charging or extended parking
Dealer references gateway, body-control, Ultium, or low-voltage diagnostics

Questions to ask

Pose these to the service advisor at intake. Request answers in writing or via email.

Were stored, pending, or historical low-voltage, gateway, body-control, charging, or BMS (Battery Management System) codes found?
Was parasitic draw or module wake/sleep testing performed?
Was the issue diagnosed as battery failure, software behavior, module fault, or charging-control issue?
What software versions were installed before and after service?
Has VIN (Vehicle Identification Number) [VIN] been checked for all applicable Ultium and Lyriq campaigns?
Will the repair order document whether the vehicle is safe to operate after service?

Documents to request

Each item should be received in writing before authorizing repair work.

Diagnostic report listing low-voltage, gateway, body-control, charging, and BMS codes
Repair order with technician notes and campaign references
Written confirmation of parasitic draw testing if performed
Written confirmation of software versions before and after service
Parts invoice showing any 12V battery or module replacement
Closed repair order showing final remedy

Pre-service evidence

Capture before drop-off. Once the vehicle leaves your possession, proving prior condition becomes significantly harder.

Photograph low-voltage or electrical warnings
Screenshot myCadillac app offline or incorrect-status behavior
Note whether the vehicle was plugged in or recently charged
Document temperature, parking duration, and whether an OTA (Over-the-Air software update) update occurred recently
Record odometer reading at service drop-off and pickup
Retain jump-start or roadside-assistance records

Service advisor interaction

Operational notes specific to the conversation at the service desk.

Ask the dealer to document whether the low-voltage event was a root cause or symptom.
A generic 'battery replaced' note is incomplete if repeated depletion occurred.
If the issue cannot be reproduced, request written confirmation that historical codes were reviewed.
If wake/sleep behavior is suspected, ask whether parasitic draw testing was performed.
Cross-platform Ultium campaigns should be checked rather than relying only on Lyriq-specific references.

Repair authorization

Cautions before signing.

Do not authorize paid low-voltage diagnostics until warranty classification is clarified in writing
If customer-pay battery replacement is proposed, request written explanation of why the root cause is not warranty-covered
Separate unrelated maintenance from electrical-system work before approval
Review authorization forms carefully before approving additional work

Post-service verification

Complete before leaving the service location. Issues that surface after departure are operationally harder to attribute to the visit.

Confirm the vehicle wakes, starts, locks, and reports app status normally
Confirm no low-voltage or charging warnings remain after a full drive cycle
Verify the repair order identifies whether testing went beyond simple battery replacement
Monitor wake/start and app behavior during the first week after service
Save the closed repair order
Document any recurrence with timing and charging state

Email templates

Documentation-focused templates for service correspondence. Tap copy to use. Subject and body are kept verbatim — paste them as-is into your email client.

pre-service inquiry

to: dealer service

Service inquiry — Cadillac Lyriq repeated 12V / low-voltage concern

Service Department, I am scheduling my [YEAR] Cadillac Lyriq, VIN [VIN], for a repeated low-voltage concern. Observed symptoms: [DESCRIBE LOW-VOLTAGE WARNINGS, APP OFFLINE BEHAVIOR, PARKING DURATION, CHARGING STATUS, AND DATES] Please confirm in writing: 1. Whether stored, pending, or historical low-voltage/gateway/body-control/BMS faults were found. 2. Whether parasitic draw or wake/sleep testing was performed. 3. Whether the issue was diagnosed as battery failure, software behavior, module fault, or charging-control issue. 4. Software versions before and after service. 5. Whether Ultium-related campaigns were checked. 6. Warranty, campaign, goodwill, or customer-pay classification. Please include these findings on the repair order. Thank you.

Warranty notes

Lyriq low-voltage, software, gateway, and body-control components should be evaluated under Cadillac's applicable EV warranty terms for VIN [VIN].
Software-only remedies do not extend warranty unless Cadillac states otherwise in writing.
Goodwill repairs do not extend warranty coverage. Confirm classification in writing.
Repeated low-voltage events should be documented as recurring service history.

Observational patterns

Low-voltage complaints should document parking duration, charging status, and whether the issue followed an OTA update.

If only the 12V battery is replaced, request written confirmation that parasitic draw and wake/sleep behavior were evaluated.

App offline behavior and failed wake/start events should be preserved because they help establish timing.

This playbook covers

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