P0562 on Cadillac: How to Diagnose & Fix
System Voltage Low
3 Cadillac models · 3 documented issues · $50-$400 repair
P0562 on Cadillac by model: symptoms, diagnosis and fix
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 2025 CT4 covering exactly this failure, holding affected inventory units from sale until reprogrammed. 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.
Sources for this issue (3)
The auto start-stop system engages and disengages harshly, causing the vehicle to shudder on restart. The AGM battery required for the system degrades quickly, and when it weakens, the start-stop system becomes erratic or disables itself. Many owners find the system intrusive.
Common Symptoms
- Harsh restart vibration
- Start-stop not functioning
- Battery warning message
- Multiple systems acting erratic
- Slow cranking on restart
How to Fix
Replace the AGM battery with a fresh ACDelco unit if the system is not functioning properly. Have the battery monitor sensor reset after replacement. GM has released recalibrations to improve start-stop smoothness. Aftermarket start-stop eliminator modules are available for owners who want to permanently disable the feature.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- AGM Battery (Group 94R / H7, 850 CCA) — main starting batteryOEM88864542 (ACDelco Gold 94RAGM)Cross-refACDelco Professional 94RAGM (O'Reilly/RockAuto listing, 850 , ACDelco Gold 94RAGMHR (88866098) — high-reserve version, sam, Optima YellowTop DH7 (Group 94R AGM)$210–$330
This is the fix part for the start-stop misbehavior described: on GM start-stop vehicles a weak or non-AGM battery makes the system restart harshly, cycle erratically, or shut itself off entirely. It must be an AGM in Group 94R/H7 — a fl…
- Auto Start-Stop Eliminator Module (permanently defeats start-stop)Cross-ref4D Tech Auto Start Stop Eliminator, 2020-2026 Cadillac XT5/X, Autostop Eliminator (autostopeliminator.com) Cadillac applic$25–$110
Optional — this is the second half of the documented fix, for owners who simply want the feature gone rather than to keep chasing it. There is no OEM part number: GM does not sell a permanent-disable part, and the dash button only turns …
Sources for this issue (1)
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 bounded 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. This card does not cover a sudden loss of power while driving and does not prescribe a battery or maintainer.
Sources for this issue (2)
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 3 models: CT4, XT6, ELR.
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?
Published repair estimates on Cadillac range from $50 to $400 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0562 on a different make?
View P0562 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.