These instructions apply to the Lexus NX Mk1 (Z1) 2014-2021. For other models, please choose your vehicle here.
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Disconnecting the 12 V battery on your Lexus NX (2014–2021) — to fit a new one, store the car, or work near the airbags — is straightforward, but on the NX 300h hybrid the 12 V battery isn’t where most people look. Here’s where it is and the safe sequence.
Find the 12 V Battery First
On the NX 300h hybrid, the 12 V battery is in the luggage compartment (under the boot floor), not under the bonnet — there are only jump-start terminals under the bonnet. On the 200t / 300 petrol NX, the 12 V battery is in the engine bay. Either way, this 12 V battery is the one you service — never touch the orange high-voltage cables or the hybrid battery.
Disconnecting Safely
- Switch off and make sure all electrical consumers are off.
- Disconnect the negative (−) terminal first, then the positive.
- Working near airbags or pretensioners? Wait 90 seconds after disconnecting before starting.
Reconnecting and Re-initialising
Reconnect positive first, then negative. The NX then needs a few items re-initialised, which mostly happen by driving:
- Steering angle sensor — drive straight and turn fully each way; the relearn completes on the move.
- Parking-assist / camera calibration.
- Re-enter the clock, audio presets and settings.
If Something Isn’t Right Afterwards
- Warning lights after reconnection (e.g. steering/assist) usually clear once the relearns complete after a short drive.
- A persistent light stores a code — look it up on autodtcs.com.
- Fit a like-for-like battery (the hybrid uses a specific AGM-type aux battery).
Frequently Asked Questions
Where is the 12 V battery on a Lexus NX 300h?
In the luggage compartment under the boot floor — the under-bonnet terminals are for jump-starting only.
Is it safe to disconnect the 12 V on a hybrid?
Yes — the 12 V is separate from the high-voltage system; just never touch the orange HV cabling.
Which terminal first?
Negative (−) off first, reconnect it last.
What needs resetting afterwards?
Steering-angle and parking-assist re-initialise (mostly by driving), plus the clock and presets.
If a warning light stays on after reconnecting, look up the code on autodtcs.com.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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