Honda All Keys Lost and Key Fob Battery Guide (Civic, Jazz, CR-V, HR-V)

When a Honda key stops working, the cause is usually far cheaper than you fear — and occasionally it is the big one, a lost or failed key. This guide covers both ends: the two-minute fob battery fix that fixes most “dead key” scares, and what a full all-keys-lost actually involves if you have genuinely lost every key. It applies to the Civic, Jazz, CR-V and HR-V.

First, rule out a flat fob battery

Before you assume the worst, check the cheapest cause. A Honda remote or Keyless Access fob runs off a small coin-cell — most commonly a CR2032 (check the number printed on the old cell before you buy). A flat cell makes the remote weak or dead and, on a Keyless Access car, throws up a key warning on the dash. Tell-tale signs it is just the battery:

• The remote lock/unlock buttons have gone weak, or only work right next to the car.
• A low-key-battery warning appeared on the dash before the fob stopped.
• Your spare key works fine when the main one does not.

How to change a Honda fob battery

• Open the fob: on a Keyless Access smart key, slide out the hidden emergency blade first, then use it (or a taped flat screwdriver) to prise the two halves apart at the seam. A bladed remote usually has a small screw or a clip.
• Note the orientation: look at which way up the old cell sits (which face is +) before you lift it out, and fit the new one the same way.
• Handle by the edge: skin oils shorten a coin cell’s life — try not to touch both faces. Clip the fob shut and reinsert the emergency blade.

The car will not start — the fob is already dead

If the fob is completely flat you can usually still get in and drive a Keyless Access Honda:

• Get in: pull the emergency blade out of the smart key and use it in the driver’s door lock (the keyhole is sometimes hidden behind a small cap on the handle).
• Start it: with your foot on the brake, hold the fob against or very close to the start button and press. The car reads the transponder at close range and starts even with a dead battery. (Check your handbook for the exact spot — it varies by model [verify against your VIN].)

If a fresh, correct battery and the hold-to-start trick both fail, the fob itself may have failed, or the fault is car-side (a weak 12V battery is a common culprit if the dash is dim or the car has stood). Both keys failing at once points away from the fob. At that point you may need a programmed replacement — a key programming job, not a copy — which our Honda key programming and Keyless Access guide explains.

When it really is all-keys-lost

If you have genuinely lost or destroyed every key, that is all-keys-lost — and it is a routine job for a mobile auto locksmith. You do not need to have the car recovered to a Honda dealer. It takes longer than adding a spare because, with no working key, the immobiliser has to be brought into a programmable state from scratch, but it is still done at the roadside.

What the all-keys-lost job involves

• Prove the car is yours: we ask for ID and proof of ownership (V5C/logbook) before generating keys to a car — standard practice and your protection.
• Get into the car: if it is locked, we gain non-destructive entry — no drilling, no broken glass. See our lost-key and lockout service.
• Cut a new HON66 blade: cut to your locks by decoding them or to a key code (this is the emergency blade inside a Keyless Access fob).
• Access the immobiliser security: read the security data the car holds with dealer-level equipment — the step ordinary key-cutters cannot do.
• Programme a fresh key: register the new bladed key or Keyless Access fob to the immobiliser via the OBD port, then test it end-to-end.

One-key Hondas are most at risk

Many used Hondas are sold with only one key. The day that single key is lost or fails, you are straight into an all-keys-lost — the most expensive version — with no fallback. If you have only one key, the cheapest insurance is a programmed spare while the working key still exists. And if a key was stolen rather than mislaid, our stolen car keys service covers disabling the missing one, which matters most on a Keyless Access car.

Roadside Honda help across Bristol & Bath

Lock City handles everything from a fob battery to a full all-keys-lost at your home, work or the roadside across Bristol, Bath and South Gloucestershire — no towing, no dealer wait. We carry the dealer-level software and the correct HON66 blanks and Keyless Access fobs to sort your Civic, Jazz, CR-V or HR-V in one visit. See our lost car keys service, the Honda key hub, or car key programming. Prices depend on the exact key, so we do not quote fixed figures — give us your registration for an exact price before we travel. Call 07967 097 899, Mon–Fri 8am–5:30pm.