Disconnect and Reconnect the Battery

Reviewed by the Service Reset editor · Updated August 22, 2026 · How we verify
Quick referenceTools10 mm spannerTime~15 minMethodDisconnect negative terminal first

These instructions apply to the Mitsubishi ASX Mk1 (GA) 2010-2023.
For other models, please choose your vehicle here.

Disconnecting the 12 V battery on a Mitsubishi ASX Mk1 (GA, 2010–2023) is a routine job for a battery change or before electrical work. There is no dealer registration to worry about, but the power windows need re-initialising afterwards and you should have your radio code ready. This guide covers the safe order of work.

Mitsubishi ASX Mk1 — the vehicle covered in this guide.
Mitsubishi ASX Mk1. Photo by Ethan Llamas via Wikimedia Commons, licensed CC BY-SA 4.0.

Where the Battery Is

The battery is in the engine bay. Lift any cover to reach the two terminal clamps. Fit a like-for-like replacement if you are renewing it — match the original specification.

Before You Disconnect

  • Check the audio system security code before you remove power — have it ready if your radio uses one.
  • Apply the parking brake and make sure all electrical consumers are switched off.
  • Make sure the ignition key is in the OFF position.
  • If working near airbags or seat-belt pretensioners, disconnect the battery and wait 1 minute before handling those parts.

Disconnecting — Correct Order

  1. Turn the ignition off and open the bonnet.
  2. Slacken the negative (−, earth) terminal first and lift the lead clear.
  3. Only undo the positive (+) terminal if you are removing the battery completely.
  4. If removing the battery, undo the hold-down clamp and lift it out upright.

Reconnecting — Correct Order

  1. Refit the battery and secure the hold-down clamp.
  2. Connect the positive (+) lead first, then the negative (−) earth lead last. Tighten both firmly.
  3. Turn the ignition on for a few seconds before starting the engine.

What to Reset Afterwards

  • Enter the radio code if prompted, and reset the date, time and presets.
  • Re-initialise the power windows — one-touch won’t work until re-taught (see our window initialise guide).
  • Re-initialise the tyre-pressure system from the menu once your pressures are correct (see our TPMS reset guide).

When a Warning Persists

One or two lights right after reconnecting is normal and should clear on a short drive. If the airbag, ABS or engine light stays on, a fault code was logged — reading it needs an OBD scanner, and you can look up what a Mitsubishi code means on our sister site autodtcs.com.

Frequently Asked Questions

Do I need to register a new battery on an ASX?

No dealer coding is required. Fit the correct battery, reconnect, and restore your settings.

Why won’t my windows auto-close after the battery change?

Disconnecting power clears the window motors’ learned positions. Run the simple re-initialise routine and one-touch returns.

How long should I leave it disconnected to reset the electronics?

Around 10–15 minutes with the doors shut lets the modules power down fully.

Will I lose my radio?

Some ASX head units ask for a security code after a power loss. Have it ready, or use a memory-saver to avoid it.

To clear the service reminder after maintenance, see our Mitsubishi ASX service indicator reset guide.

Independent guide — not affiliated with Mitsubishi. Always follow your official service manual and safety precautions. Read our full disclaimer.

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