01 Thinking of Upgrading to LED Headlights? Here's What You Mu… • 02 Is it bad to brake while cruise control is enabled? • 03 5 Spark Plug Replacement Mistakes That Are Killing Your Eng… • 04 How to Start a Rebuilt Engine for the First Time • 05 This Is How to Fix Sensor-Related Fuel Consumption Problems… • 06 This Is Why It’s Almost Impossible To Sink A Modern Cruise … • 07 Long Distance SUV vs. Saloon Car Review: Which Is the Best … • 08 The Most Problematic Mitsubishi Cars: A Comprehensive Review • 09 P0116 – Engine Coolant Temperature Range Fault: Causes and … • 10 Here's Why Your Car Feels Sluggish Even With A Full Tank Of… •

DTC codes / P05xx · Vehicle speed, idle control and auxiliary inputs / P0562

P0562System Voltage Low

P0562 means the engine control module (ECM) has detected that the vehicle's main electrical system voltage has dropped below the manufacturer's specified threshold for a calibrated amount of time. In plain English, the computer sees the battery and charging system operating at too low a voltage while the engine is running, which can starve electronic modules of the power they need to function correctly.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

  • The check engine light or battery/charging warning light illuminates on the dashboard.
  • The engine may crank slowly or hesitate to start, especially after sitting overnight.
  • Interior and exterior lights dim or flicker, particularly at idle when alternator output is lowest.
  • Electronic accessories such as the radio, power windows, or climate control may behave erratically or reset.
  • The transmission may shift harshly or enter limp mode because solenoids and the transmission control module need stable voltage.
  • Often no symptoms besides the warning light, especially if the voltage drop is brief or intermittent.

Common causes, most likely first

  1. A failing or worn-out battery that cannot hold a charge under load.
  2. A weak or failing alternator that is not producing enough current at idle or under electrical load.
  3. Corroded, loose, or damaged battery cables and terminals creating high resistance in the charging circuit.
  4. A slipping or worn serpentine belt that drives the alternator inconsistently.
  5. Poor ground connections between the engine, chassis, and battery that raise resistance in the return path.
  6. A parasitic draw that drains the battery overnight, leaving system voltage low on startup.
  7. A faulty voltage regulator inside the alternator or a damaged sense wire causing incorrect charging output.

How to diagnose and fix it

  1. Perform a visual inspection of the battery terminals, cables, and grounds for corrosion, looseness, or damage, and clean or tighten as needed.
  2. Measure battery voltage at rest with a digital multimeter; a healthy fully charged battery should read about 12.6 volts.
  3. Check charging voltage at the battery with the engine running and accessories off; it should be roughly 13.5 to 14.5 volts.
  4. Load-test the battery with a conductance tester or carbon pile to confirm it can supply cranking current without dropping excessively.
  5. Inspect the serpentine belt and tensioner for wear, glazing, or slippage that would reduce alternator output.
  6. Perform a voltage drop test on the positive and ground circuits between the alternator, battery, and chassis to find hidden resistance.
  7. If voltage output is low and all connections are good, remove the alternator for bench testing or replacement.

Why a New Battery Does Not Fix P0562

  • A common misdiagnosis is replacing the battery when the real problem is a corroded ground strap between the engine block and chassis, which raises resistance and lowers measured system voltage.
  • P0562 can be set by a brief voltage dip during cranking if the battery is marginal, so the code may appear only on cold mornings and clear itself after the engine runs.
  • Some vehicles set P0562 when the alternator's internal voltage regulator fails intermittently, producing normal voltage at idle but dropping under load when the engine bay heats up.
  • A parasitic draw from a stuck relay or aftermarket accessory can drain the battery overnight and trigger P0562 on the first start of the day even though the charging system tests fine.
  • The ECM itself can cause a false P0562 if its power or ground feeds are compromised, so check the module's own supply circuits before condemning the alternator.

Can I keep driving with P0562?

You can usually drive a short distance to a repair shop, but avoid long trips, heavy electrical loads such as rear defroster and headlights together, and night driving where a voltage collapse could kill the engine or lights. If the battery warning light is on and voltage is dropping, stop driving and arrange a jump start or tow to prevent being stranded.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage