B12C5 on Honda

Engine start/stop switch failure (Honda, Acura)

Severity: Inspect soon

Honda's bulletin says the car may not start on the first press of the start/stop button, so it can leave you unable to start the car.

This page covers only what differs on Honda. For what B12C5 means, the ranked causes and the test order, see the B12C5 guide.

2016–2018 · HR-V
Supported by vehicle data
Honda extended warranty on the keyless start system for B12C5, and an HR-V owner reports the switch replaced after the car stopped starting reliably. Whether the extension still applies is not verified.

A20-098Status unverified
Start/stop switch failure, DTC B12C5
2015–2017fit · issued December 9, 2020 · NHTSA 10184317
Warranty extension for the keyless start system on Fit models that may not start on the first press.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Honda owner notification letter: may not start on first press of ENGINE START/STOP, DTC B12C5; warranty extended (2016-2018 HR-V) — American Honda Motor Co. , February 16, 2021
NHTSA complaint ODI 1666455 (2017 Honda HR-V) — NHTSA Office of Defects Investigation
Honda A20-098: vehicle may not start on first press of the ENGINE START/STOP button, DTC B12C5 (Engine Start/Stop Switch Failure); warranty extension (2015-2017 Fit) — American Honda Motor Co. , December 9, 2020

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