P0562 System Voltage Low
Caution
The engine computer saw the car's electrical voltage drop too low. A weak battery, a failing alternator or a loose or corroded connection is the usual cause. The car may not restart or may stall, so get it checked soon.
- Safe to drive?
- Short trips only, it can strand you
- Typical cost at a shop
- $125-$1,073 RepairPal national averages, parts and labor
- Emissions test
- Yes, while the check engine light is on, most OBD emissions tests fail the car.
Watch the system voltage with the engine off and running to tell the battery from the alternator.
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Codes and live sensors are free in the app. Obie, the AI mechanic, is part of ScanMyCar Pro.
What it means
With the engine running, the alternator charges the battery and powers the car. The engine computer watches the supply voltage it receives. P0562 means that voltage stayed below its limit for a while. The battery, the alternator, the belt that drives it, or the cables and grounds between them are the usual suspects.
The technical version
The computer reads its own supply voltage, usually the ignition feed. P0562 sets when it stays below a calibrated limit for a set time with the engine running. P0563 is the high side. A voltage drop during cranking from a weak battery can also set it on some cars. Other modules may log low-voltage codes at the same time.
Official name: System Voltage Low.
Symptoms
- Battery or charging warning light.
- Dim or flickering lights.
- Slow cranking or no start.
- Several warning lights or odd electrical behavior at once.
Causes, most likely first
| Cause | How likely | How to tell |
|---|---|---|
| A weak or failing battery | most common | Slow cranking; the battery is old or reads low after resting. |
| A failing alternator or voltage regulator | common | Running voltage stays near battery voltage or drops with loads on. |
| Loose or corroded battery cables or grounds | common | White or green corrosion; a terminal that moves by hand. |
| A slipping or broken drive belt | less common | Squealing, especially at start-up or with loads on. |
| A wiring fault in the computer's power feed | rare | Battery and alternator test good. |
How likely is our ranking from repair data and common practice, not a published rate.
What the live data shows
Control module voltage is a standard OBD reading. With the engine off and rested, a healthy battery reads about 12.4 to 12.7 V. With the engine running, a healthy charging system usually holds about 13.5 to 14.7 V, and it should stay there when you switch on the headlights, fan and rear defroster. A running voltage near 12 V or lower points to the charging system.
What to check first, in order
-
Clean and tighten the battery terminals and check the ground cables.
Bad connections are common and cheap to fix.
What the data shows: No reading needed.
Cost: free to look
-
Read module voltage engine off, then running with loads on.
It tells the battery from the alternator.
What the data shows: About 12.4 V off, about 13.5 to 14.7 V running.
Cost: no cost if you have a scanner
-
Have the battery load-tested.
A weak battery can read fine at rest.
What the data shows: Not a scanner step.
Cost: free at many parts stores
-
Replace the battery if it fails the test.
The most common cause.
What the data shows: Cranking is quick and voltage holds.
Cost: $456-$493 at a shop (Battery replacement, RepairPal)
-
Replace the alternator if running voltage stays low.
It is not charging.
What the data shows: Running voltage back in the normal range.
Cost: $802-$1,073 at a shop (Alternator replacement, RepairPal)
Is it safe to drive?
Caution
Short trips only, it can strand you. If the alternator is failing, the battery drains while you drive.
Treat it seriously. If the alternator is failing, the car runs on the battery alone until it goes flat, and then the engine can stall in traffic. If the battery light is on, drive straight to a repair or home, with as few electrical loads as possible. If it only happened during a hard start, it may be the battery.
Stop driving and get help if
- The battery or charging light comes on while driving.
- Lights dim, gauges act strangely or warning lights come on together.
- You smell burning or hear a squeal from the belt.
What it costs
| Repair | Typical cost |
|---|---|
| Check engine light diagnosis (shop)RepairPal, updated September 3, 2026 | $125-$183 |
| Battery replacementRepairPal, updated September 3, 2026 | $456-$493 |
| Alternator replacementRepairPal, updated June 18, 2026 | $802-$1,073 |
National averages for the full job at a shop, parts and labor, from RepairPal (updated June 18 and September 3, 2026). Your price depends on the car and the area. Many of the first checks on this page cost nothing with a scanner.
Can I clear it? Will it come back?
After the repair, clear the code and drive with your normal loads. Recheck module voltage running: it should stay in the normal range, and the code should not return.
Will it fail an emissions test?
Yes, while the check engine light is on, most OBD emissions tests fail the car.
Related codes
Also related, no guide yet: P0560, P0563.
How Obie handles P0562
Obie reads module voltage with the engine off and running and tells you whether the pattern points to the battery, the alternator or a connection. Obie is part of ScanMyCar Pro. Codes and live sensors are free.
Questions people ask
Is P0562 the battery or the alternator?
Either. Check voltage with the engine off and running: low running voltage points to the alternator.
Can I drive with P0562?
Short trips only. If the alternator is failing, the car can stall when the battery runs down.
Can a bad battery cause P0562?
Yes, especially if it set during a slow start.
Sources
- RepairPal: P0562 code page repairpal.com
- RepairPal: Check engine light diagnosis (shop) (updated September 3, 2026) repairpal.com
- RepairPal: Battery replacement (updated September 3, 2026) repairpal.com
- RepairPal: Alternator replacement (updated June 18, 2026) repairpal.com
- Texas DPS emissions testing FAQ dps.texas.gov
- Arizona myazcar.com: OBD and the check engine light myazcar.com
A guide, not a diagnosis. This page describes what P0562 generally means across OBD2 cars. What is actually wrong with your car depends on its live data and its history, and any repair decision deserves a proper diagnosis, whether that is you with a scanner or a professional with a lift.