Certain generations of Accord and CR-V vehicles chew through batteries. Leave one of these sitting a couple days and there's a good chance it won't start due to an underpowered battery, parasitic drains, and an ineffective battery charging system.
Over the years, Honda has released multiple technical service bulletins (TSB) outlining potential software fixes for battery problems. However, those fixes aren’t always effective and have been limited to the 2012 and 2017 model years.
Why the Accord and CR-V Batteries Keep Dying ∞
The batteries are contending with a parasitic drain, which happens when an electrical component continues to draw power from the battery even after the vehicle is turned off. Even a slight draw can empty the battery if left unattended for a couple days.
Vehicle Stability Assist (VSA) Drain ∞
The vehicle stability assist (VSA) software in the 5th generation CR-V may continue to draw power from the battery after the vehicle is turned off.
In TSB #17-032, titled Parasitic battery draw from VSA modulator (vehicle will not start), Honda says the VSA software logic may not shut down correctly when:
- The electronic parking (EPB) is applied within 3 to 4 seconds of the vehicle being shut off, or…
- The EPB switch is held for a 3 to 4 second duration when the vehicle is off
The VSA modulator will continue to draw 350mA of power after the vehicle is shut off. More than enough to drain the battery after a day or two.
Honda recommends technicians install a software update to the VSA modulator-control unit and perform a VSA sensor neutral position memorization procedure. Unfortunately this TSB only applies to a specific VIN range of 2017 CR-Vs.
- Failed part: #57114-TLA-A04
- Defect Code: 03214
- Symptom Code: 03203
A/C Relay Drain ∞
The A/C relay in 4th generation CR-Vs may stay engaged after the engine is shut off, according to TSB #A11090M.
An electrical short and failed resistor means the relay gets stuck in the open position, draining the battery through the multiplexing system.
The relay (part #39794-SDA) is a $9 part and an easy DIY repair.
Other Battery Problems ∞
It’s not just parasitic drains that are killing off CR-V batteries. Here’s a look at a couple other common problems in post-2010 CR-Vs.
Wrong battery management charge mode ∞
In November of 2012, Honda released SB #12-041 titled The Battery is Dead and Needs Multiple Jump Starts. Two years later they released SB #14-071 titled _ Battery Management Software Update_. Both service bulletins describe an issue in the powertrain control module (PCM) where the proper charge mode for the battery is not selected when the vehicle is turned off.
The system’s computers need a software update with a functional battery present.
- Failed part: #37820-R5A-A65
- Defect Code: 5JS00
- Symptom Code: JL500
Defective alternator ∞
When the engine is running, the alternator charges the battery. But the CR-V’s alternator can sometimes over or under charge the battery, reducing its performance either way.
In February of 2013, Honda released TSB #12-002 outlining procedures for alternator testing with a GR8 Diagnostic Battery Station.