MajorCommonElectrical

Honda Jazz: 12V Auxiliary Battery Parasitic Drain — BCM Software Defect

12V Auxiliary Battery Parasitic Drain — BCM Software Defect is a common electrical fault on the Honda Jazz on the 2020–2022 cars, and we rate it major. Putting it right costs $250 to $550 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 51 documented faults on the Honda Jazz.

Vehicle: Honda Jazz
Years: 2020–2022
Fuel: hybrid
Gearbox: auto
System: Electrical

This page covers the Honda Jazz as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Honda Jazz faults51 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the 12V battery yet. We would rather show none than show a picture of a different part.

What goes wrong

Early GR Jazz e:HEV models (primarily 2020–2021 build dates) contained a Body Control Module (BCM) software deficiency that kept the boot lock circuit and telematics control unit active after the car was locked. This parasitic current draw could flatten the small 12V auxiliary battery within 7–10 days of parking. Honda identified the fault and issued a BCM software update (replacing version M0E010 with M0E020). Even on updated vehicles, the 12V battery in e:HEV models has a shorter service life than conventional cars — typically 2–3 years — due to the hybrid management system's ongoing auxiliary power demands when parked.

What you would notice

Car refuses to start after 7–10 days of parking without being driven
Dashboard goes blank or displays a power loss warning on approaching the car
Key fob fails to unlock doors after a short lay-up period
Battery warning light on instrument cluster after returning to the car
Repeated 12V battery replacements within 2–3 years of ownership

How to check it

Where to look. 12V auxiliary battery under bonnet; Body Control Module behind dashboard

Ask for the BCM software version history (Honda dealer scan required).
Check the 12V battery manufacture date sticker on the battery casing.
Perform a parasitic draw test if the car has sat unused for more than a week.
Verify the BCM update has been stamped in the service history.

Parts involved: 12V battery.

What it costs to put right

$250 to $550 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the BCM software been updated by a Honda dealer, and is there a record of the update in the service history?”
“Has the 12V battery been replaced, and how old is the current battery?”
“Has the car ever failed to start after sitting unused for a week or more?”

Now check the Honda Jazz you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Honda Jazz buyer questions

Is 12v auxiliary battery parasitic drain — bcm software defect serious on a Honda Jazz?

We rate it major and common on the Honda Jazz. Early GR Jazz e:HEV models (primarily 2020–2021 build dates) contained a Body Control Module (BCM) software deficiency that kept the boot lock circuit and telematics control unit active after the car was locked. This parasitic current draw could flatten the small 12V auxiliary battery within 7–10 days of parking. Honda identified the fault and issued a BCM software update (replacing version M0E010 with M0E020). Even on updated vehicles, the 12V battery in e:HEV models has a shorter service life than conventional cars — typically 2–3 years — due to the hybrid management system's ongoing auxiliary power demands when parked.

How much does it cost to fix on a Honda Jazz?

$250 to $550 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Honda Jazz years are affected?

Our research records this fault on the 2020–2022 Honda Jazz. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Ask for the BCM software version history (Honda dealer scan required). Check the 12V battery manufacture date sticker on the battery casing. Perform a parasitic draw test if the car has sat unused for more than a week. Verify the BCM update has been stamped in the service history. Look here: 12V auxiliary battery under bonnet; Body Control Module behind dashboard