P0562 on Cadillac: How to Diagnose & Fix
System Voltage Low
2 Cadillac models · 2 documented issues
P0562 on Cadillac by model: symptoms, diagnosis and fix
A low ELR 12-volt battery can leave control modules unable to wake and prevent a normal start. GM also issued VIN-gated program 14395A for a specific 2015 OnStar-module battery-drain condition; that program expired in 2017 and is not proof of a universal drain.
Common Symptoms
- Control modules do not wake
- Vehicle will not enter Ready mode
- Low 12-volt battery after parking
How to Fix
Test the AGM battery and charging state, preserve DTC and low-voltage history, and diagnose the source of discharge before replacement. For a 2015 vehicle, ask a Cadillac dealer to check VIN and program history.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (2)
A software defect in the serial data gateway module can leave vehicle modules awake after an over-the-air update completes, so the car never fully goes to sleep. The result is partial or complete 12-volt battery drain — the car will not start after sitting, or starts weakly and throws a cascade of unrelated module warnings caused by low system voltage. GM opened Customer Satisfaction Program N242435630 for the 2023-2024 CT4 and later added the 2025 CT4, covering exactly this failure, including affected units still in dealer inventory. The same low-voltage-after-sitting complaint appears in owner discussion of GM's OTA update rollouts more broadly, so the symptom is worth checking on any OTA-capable CT4 that repeatedly wakes up with a dead battery.
Common Symptoms
- Vehicle will not start after sitting a few days
- Repeated dead 12-volt battery
- Multiple unrelated module warning messages on startup
- Battery drain begins after an over-the-air update
How to Fix
Have the dealer perform Customer Satisfaction Program N242435630, which reprograms the serial data gateway module — no new parts are required and the program is free of charge. Before or after the reprogram, have the 12-volt AGM battery load-tested and recharged properly; a battery that has been deeply discharged several times is usually damaged and should be replaced, not just recharged. If drain persists after the reprogram, a parasitic draw test module-by-module is the next step rather than repeatedly replacing batteries.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (4)
- GM Customer Satisfaction Program N242435630: Serial Data Gateway Module (Revision 03)tsb
- GM Releases Fix For 2025 Cadillac CT4 Battery Drain | GM Authorityarticle
- OTA Update GM N25-249834 | Cadillac Owners Forumforum
- 12V battery dead again: GM says this is normal if you don't drive the car more | Cadillac Owners Forumforum
P0562 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 P0562 mean on a Cadillac?
P0562 stands for "System Voltage Low." P0562 means the engine computer detected that the vehicle's system (battery/charging) voltage is too low for normal operation. The computer constantly monitors charging-system voltage because nearly every sensor, injector, and module depends on a stable supply; sustained low voltage can cause erratic behavior and other false codes. This is most often a charging or battery problem — the alternator isn't keeping up, the battery is weak, or there's resistance in the cables/grounds. You may notice dim lights, slow cranking, or multiple unrelated warning lights. On Cadillac it is documented across 2 models: ELR, CT4.
What are the most common causes of P0562?
The most common causes of P0562 are: Failing alternator or worn alternator brushes/regulator, Weak, old, or discharged battery, Corroded, loose, or damaged battery cables and terminals, Bad engine or chassis ground connections, Slipping, glazed, or broken serpentine/drive belt, High resistance in charging system wiring or fusible link, Faulty PCM voltage reference or charging-system control. The specific cause varies by vehicle.
How much does it cost to fix P0562 on a Cadillac?
Repair costs vary widely with the root cause and Cadillac 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.