Your Honda is telling you that the ignition is in accessory or ACC mode, meaning the electrical system is powered without the engine running. This lets you use radios, navigation, climate controls, and other electronics without idling the engine.
What “Accessory Mode” means in a Honda
Accessory mode (ACC) is a power state that turns on only the vehicle’s electrical systems. The engine stays off, which helps you use features like the radio, display screens, and power windows without burning fuel or producing exhaust.
- ACC powers essential electronics (radio, infotainment, display screens, navigation, charging ports, climate control interfaces) but does not run the engine.
- The ignition or instrument cluster will usually show an indicator such as “ACC” or “Accessory.”
- In push-button Hondas, ACC is typically reached by a specific sequence of button presses without pressing the brake; ON, with more systems active, is reached with another press or when you press the brake and the button in the right model-specific way.
- In traditional key-equipped Hondas, turning the key to the ACC position powers the same subset of electricals without starting the engine.
When you’re ready to drive, you’ll switch from ACC to ON (or start) depending on your model, following the standard ignition sequence described in your owner’s manual. If you’re unsure which sequence your model uses, check the manual or ask a dealer for model-specific steps.
Why you might see “Accessory Mode” unexpectedly
There are a few common reasons this message or state appears, and most are normal or easily fixed. If you aren’t actively trying to use ACC, a quick check can rule out simple causes before seeking service.
- You pressed the start button or turned the ignition to ACC by mistake (common with push-button starts).
- The car’s key fob was detected, and the system moved to ACC without you intending to drive.
- A recent remote start or after-market device interaction left the car in ACC while you wait to drive.
- A sensor or switch (for example, the brake pedal switch or ignition switch) isn’t reading correctly, causing the system to default to ACC.
- The 12-volt battery is weak or recently discharged, so the vehicle powers only the minimal ACC circuits until the battery is recharged or replaced.
- In some models, certain features require ON mode; if the vehicle thinks you aren’t ready to drive, it may stay in ACC to protect systems.
Most of these situations are harmless and temporary. If ACC persists and you’re unable to access other functions or start the engine, consult your owner’s manual or contact a Honda dealer or qualified technician to diagnose electrical or sensor issues.
How to move out of Accessory Mode and start driving
To resume driving, you’ll typically need to advance to ON (or START) and, if you’re ready to move the engine, engage START with the brake pedal. The exact sequence varies by model and year, so use this as a general guide and refer to your manual for model-specific steps.
- From ACC to ON: press the Start/Stop button once more (without depressing the brake on some models) to energize more systems into ON.
- To start the engine: depress the brake pedal (in most models) and press the Start/Stop button to engage START and start the engine.
- To turn the car off from ACC/ON: press the Start/Stop button again until the vehicle shuts down completely, returning to OFF.
If your model uses a traditional key, this sequence may look different, but the concepts are the same: ACC powers electronics, ON energizes a broader set of systems, and START begins engine operation. When in doubt, follow the owner’s manual or contact a dealer for model-specific instructions.
Battery health and safety considerations
Leaving accessories on in ACC for an extended period can drain the 12-volt battery, potentially preventing you from starting the car. If you notice slow engine cranking, dim lights, or warning chimes, have the battery tested. Some Honda models also include energy-management features that protect the battery, but prolonged ACC use should be minimized when the car isn’t running.
To minimize risk, avoid running high-draw features (like climate systems at high power) for long periods in ACC, and if you anticipate needing power for an extended time, start the engine or consider a portable charger if appropriate for your situation.
If you suspect a fault (e.g., the car stays in ACC despite attempts to start, or the brake/ignition sensors don’t respond as described in the manual), seek service promptly to prevent battery or electrical system damage.
Summary
Accessory mode in a Honda is a normal ignition state that powers only the car’s electrical systems without starting the engine. It’s commonly accessed via the start button sequence in push-button models or by turning the key in traditional ignition. You may see ACC when testing electronics, after remote starts, or if a sensor misreads. To drive, move from ACC to ON and then use the brake to start the engine, or follow your model’s specific sequence. Keep an eye on battery health, as extended ACC use can drain the 12-volt battery, and consult your manual or a dealer if ACC behavior seems abnormal.