HandsFreeLink Has a "Parasitic Draw" That Drains the Battery

While most cars nowadays come with some sort of hands-free calling system, it wasn't that long ago that it was considered to be a luxury feature. Certain 2004 Acura vehicles were among the first to get a Bluetooth-enabled system for connecting their phones to their cars, but it came with a giant parasite of a catch.

The blue user interface of HandsFreeLink is shown making a call via a BlackBerry.

Acura's parent company Honda was one of the first to offer a hands-free system called HandsFreeLink. In their rush to beat the competition, however, they missed a defect that allows the system to stay on at all times. Yes, even after the car has been turned off. This parasitic electrical drain puts strain on the entire electrical system and had led to numerous reports of dead batteries and burnt out alternators.

TSB Shows Internal Knowledge of a 250mA Draw

Acura mechanics received their first Technical Service Bulletin (TSB) about HandsFreeLink battery drain problems in 2005. They were told the system can get "locked up" in an "on" position and that the "system staying on may cause a dead or low battery while the vehicle’s ignition switch is off." Sounds about right.

Unfortunately the only suggested solution was to replace any units that owners complained about with the same, defective product.

A 2008 TSB went a but further into explaining the problem by saying that the HandsFreeLink "control unit has an internal problem, which creates a parasitic current draw of 250mA.” That's a big enough drain to empty the battery overnight and make it impossible to start the vehicle without a jumpstart.

The Parasitic Drain Lawsuit

Before the release of the second TSB, a lawsuit was filed in California by owners tired of needing multiple jump starts, new batteries, and alternator replacements.

The lawsuit says owners are left with no good options. Either disconnect the system that they paid for, or replace it with another defective $1,000 unit and hope nothing bad happens. Spoiler alert … it will.

The case is moving forward after a round of dismissals

Honda was not impressed with the lawsuit's claims. Unfortunately neither was the judge. who dismissed any claims about warranty and consumer proctection laws because the plaintiffs waited too long.

The judge did rule that the plaintiffs provided enough evidence to move forward on claims that the automaker concealed possible defects in the Acura cars.

Vehicles That Might Have This Problem

Watch out for this problem in the following generations and model years.

Model Generation Years
MDX 2nd Generation 2007—2013
TL 3rd Generation 2004—2008

Owner Complaints

Here are some possibly related problems from owners over at CarComplaints.com. Click on one of the links to read about the problems and see how they compare to your experience.

Model Year Problem Count Mileage Cost
MDX 2014 battery drain 2 34000 $300
2011 low battery warning 1 95000 N/A
2010 replace battery light comes on 1 53000 N/A
battery keeps going dead 1 0 N/A
2009 battery drains 2 96500 $500
2007 dead battery 2 110500 N/A
parasitic draw after multiple dead battery events 7 122000 $100
RDX 2013 battery keeps going dead 3 43500 N/A
2008 battery drains 1 95000 $50
2007 parasitic battery drain 1 14000 N/A
RL 2008 dead battery 1 68000 N/A
TL battery drains 4 82500 $200
2007 battery dies overnight 4 57000 $200
2006 battery drains 13 105500 $200
2005 battery drains 4 132000 N/A
TSX 2006 parasitic drain of battery by hands free/bluetooth 1 84500 N/A
2004 dead battery after sitting 1 78000 N/A
This data was last updated on .

Further Reading


  • HansFreeLink Lawsuit Survives Dismissal of Claims

    Despite a judge ruling that certain warranty and consumer protection claims aren't applicable, the HandsFreeLink battery drain lawsuit will be allowed to continue on the claim that the automaer concealed possible defects.

    Published in #lawsuit on


This article was published in #electrical, #lawsuit, and last updated on by Scott McCracken.

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