Car & driving · Free
P0562: system voltage low
P0562 means the engine computer measured a supply voltage that was too low. The usual reasons are a weak battery, poor battery terminals or an alternator that no longer charges properly. Live data tells you which one in about a minute.
- No account
- Runs on your device
- Phone & desktop
Check your car for P0562
Runs on your device
Connect your OBD2 adapter
- Plug the adapter into the OBD2 port – usually under the steering wheel, near the pedals.
- Switch the ignition on, or start the engine.
- Bluetooth adapter? Turn Bluetooth on. Nothing else to set up.
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Classic Bluetooth adapter (PIN 1234)? Pair it in your system settings first, then choose USB or paired Bluetooth – on a computer or in Chrome 138+ on Android. Wi-Fi adapters cannot work in a browser.
Your car data stays on your device. The page talks to the adapter directly; codes, VIN and values are never uploaded.
Never use it while you drive. Set things up before you set off, or let a passenger handle the phone. Standard OBD2 reads engine and emissions data; ABS, airbag and coding need workshop equipment.
What P0562 means
Every control unit in the car needs a stable supply voltage. With the engine off, a healthy 12-volt battery shows about 12.4 to 12.7 V. With the engine running, the alternator should raise it to roughly 13.8 to 14.6 V to power the car and recharge the battery.
The engine computer measures its own supply voltage and stores P0562 if it stays below a threshold for a while. Low voltage can also confuse other modules, so random warning lights and communication codes often show up at the same time.
Symptoms of P0562
- Slow cranking or no start.
- A battery warning light, dim lights or a weak blower.
- Other warnings or communication codes that come and go.
- Start-stop no longer works.
Causes of P0562, cheapest first
Work down the list in order: the first checks cost little or nothing, the last ones are jobs for a workshop.
Loose or corroded battery terminals
White or green deposits and loose clamps cause voltage drops. Clean the terminals and tighten the clamps: the cheapest fix.
A weak or old battery
Car batteries often last around five to seven years, less with many short trips. Test it with the engine off; if the voltage collapses when starting, it needs charging or replacing.
A slipping or worn drive belt
The alternator is driven by a belt. A squealing, glazed or loose belt slips, and the alternator does not charge fully.
A faulty alternator or regulator
If the voltage stays near battery level with the engine running, the alternator or its regulator is not charging.
Poor ground connections
Corroded earth straps between engine, body and battery add resistance. Check them, especially after accident repairs.
Can you drive with P0562?
Drive on, but check it now. The car may leave you stranded, and some functions can fail when the voltage drops further. If the battery light is on while you drive, the alternator is probably not charging: switch off what you can and head straight home or to a workshop.
Check P0562 with OBD Studio
Connect your adapter above, or try the demo car, then:
- With the engine off, read Control module voltage in Live data. About 12.4 to 12.7 V is a charged battery; much lower means it needs charging.
- Start the engine. The value should rise to about 13.8 to 14.6 V. The Overview tab also says whether the alternator seems to be charging.
- Switch on the headlights, blower and rear window heater: the voltage may dip briefly but should stay above about 13 V.
- Set an alert below 12 V in Live data to catch drops while you drive.
More fault code guides
Each of these codes has its own page with causes ranked by cost and the checks that go with them.
- P0420Catalyst efficiency below threshold
- P0171System too lean
- P0300Random or multiple misfire
- P0455EVAP system large leak
- P0442EVAP system small leak
- P0128Engine warms up too slowly
- P0172System too rich
- P0401EGR flow too low
- P0101Air flow sensor implausible
- P0135Front O2 sensor heater
- P0016Crankshaft and camshaft out of step
- P0011Intake camshaft timing over-advanced
- P0141Rear O2 sensor heater
- P0113Intake air temperature sensor high
- P0457Fuel cap loose or missing
- P0299Turbo underboost
- P0700Transmission control system fault
- P0087Fuel rail pressure too low
- U0100Lost communication with engine computer
More OBD Studio pages
Frequently asked questions
Can a bad battery cause P0562?
Yes, it is one of the most common causes. A battery that cannot hold its charge drops below the threshold, especially while starting. Test it and the charging voltage before you replace anything.
What voltage should my car show while running?
Most cars show about 13.8 to 14.6 V with the engine running. Some modern cars with smart charging vary more and briefly show lower values; what counts is that the voltage rises clearly above battery voltage.
Why do several codes appear together with P0562?
Low voltage affects every electronic module. Communication codes and sensor faults that appear along with P0562 often disappear once the supply voltage is back to normal.
Can I read P0562 without going to a workshop?
Yes. With any ELM327-compatible Bluetooth LE or USB adapter, OBD Studio on this page reads P0562 and every other stored code for free, shows the freeze frame and clears the code after the repair. Nothing to install, no account.
