System Voltage Low Below ECM Threshold
The KOHLER-COMMAND-P0562 (Kohler Command) diesel fault code means: System Voltage Low Below ECM Threshold. This is a moderate severity code.
Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.
- Keep running?
- Limited operation only
- DIY difficulty
- moderate
- Estimated cost
- $20-$200 DIY depending on part needed. Battery replacement runs $60-$90 at most parts stores. A rectifier-regulator is $25-$80 OEM. Pro shop diagnosis and repair typically $80-$250 including labor.
What Are the Symptoms of KOHLER-COMMAND-P0562?
- Engine cranks slowly or struggles to start, especially on a warm day
- EFI fault light flashes or stays on during operation
- Engine runs rough or stumbles at low throttle
- RPM hunting or surging under light load
- Intermittent stalling, especially right after engaging the PTO
- Dash warning light illuminated on Toro, Exmark, or Scag operator panel
- Fuel injector pulse feels weak or engine response is sluggish
What Causes KOHLER-COMMAND-P0562? (Most Likely First)
- Weak or partially discharged battery not holding 12.4V or above at rest Very Likely
- Charging system not producing adequate voltage, typically caused by a worn or slipping alternator stator on the engine Very Likely
- Loose, corroded, or broken battery cable connections at the battery terminals or chassis ground point Likely
- Worn or glazed charging belt slipping and reducing alternator output Likely
- High-resistance ground path between engine block and frame causing voltage drop under load Possible
- ECM power supply circuit has a poor connection or corroded pin at the ECM harness connector Possible
- Parasitic draw from an accessory or damaged wiring harness slowly draining the battery between uses Less Likely
Can I Keep Running It with KOHLER-COMMAND-P0562?
Limited operation only. KOHLER-COMMAND-P0562 is rated moderate severity. Keep runs short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What does Kohler Command code P0562 mean on my commercial mower?
It means the ECM measured the system voltage on the engine electrical supply circuit below the minimum threshold it needs to operate the fuel injection system reliably. On Kohler EFI Command engines that threshold is roughly 10.5V to 11.0V. The most common reasons are a weak battery, a failing charging stator, or corroded battery cables.
Can I keep mowing with P0562 active?
You can in the short term, but it is not a great idea on an EFI model. Low voltage causes the ECM to miscalculate injector timing and fuel delivery, which leads to rough running and can eventually cause a hard stall in the middle of a job. Fix the charging issue before relying on it for a full commercial day.
How much does it cost to fix P0562 on a Kohler Command EFI engine?
If a battery swap fixes it, you are looking at $60-$90 in parts and about 15 minutes of your time. A new rectifier-regulator is $25-$80 depending on the model. If a dealer needs to diagnose and replace the charging stator inside the engine, labor pushes the total to $150-$300.
Will my mower start next time with this code stored?
Probably yes if the battery still has enough charge to crank the engine, but P0562 often gets worse over a season. A battery that borderlines today may not start the engine on a cold morning next week. Get the charging system tested and replace the battery if it is more than three years old.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose KOHLER-COMMAND-P0562?
Start with a static battery voltage check. With the engine off and key in the OFF position, measure DC voltage across the battery terminals. You want 12.4V or higher. Below 12.0V means the battery is too weak to feed the ECM reliably and is your first fix.
Start the engine and measure battery voltage again with a multimeter across the terminals. At idle you should see 13.2V to 14.7V. If voltage stays below 13.0V at 3000 RPM, the charging system is not keeping up and the stator or rectifier-regulator is suspect.
Inspect both battery cable ends. Remove the positive and negative cables one at a time, clean the terminals with a wire brush, and check for corrosion under the cable boots. Green or white powder buildup here will cause a voltage drop that triggers P0562 even with a good battery.
Check the main chassis ground strap from the engine block to the mower frame. Wiggle it and look for fraying or loose bolts. Use your multimeter on the DC millivolt setting and measure voltage drop across that strap while the engine runs. More than 200 millivolts of drop across a ground strap means it needs to be replaced or cleaned.
Locate the charging belt on the engine. With the engine cold and the key out, try to deflect the belt with your thumb. More than about half an inch of deflection means it is loose. Also look for glazing or cracking on the belt surface. A slipping belt cuts charging output directly.
If the battery and cables check out, test the rectifier-regulator output. Backprobe the output wire from the rectifier-regulator with the engine running at full throttle and compare that reading to the battery terminal voltage. A large difference between the two points to a failed rectifier-regulator.
If all the above pass, connect a Kohler PCM diagnostic tool to the EFI data link on ECV-series engines. Live data will show you the actual voltage the ECM is seeing on its supply pin. A reading lower than what your multimeter shows at the battery means there is resistance in the harness between the battery and the ECM, and you will need to trace the supply wires pin by pin.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines P0562 as a generic OBD-II code)
Which Vehicles Commonly Get KOHLER-COMMAND-P0562?
- Kohler Command Pro ECV730 (EFI 25HP) on Exmark Lazer Z
- Kohler Command Pro ECV749 (27HP EFI) on Toro TimeCutter and Grandstand
- Kohler Command Pro ECV880 (37HP EFI) on Scag Turf Tiger and Bad Boy Outlaw
- Kohler Command Pro EFI 999cc on Wright Stander and Hustler Super Z
- Kohler Command Pro CV730 (23.5HP) on Ferris IS2100Z
- Kohler Command Pro CV640 (19HP) on smaller Scag and Exmark walk-behinds
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