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2018 TLX Battery Draining Overnight - Help!

0

Chris P. · rep 0 · May 22, 4:57 AM · 1 replies · solved · Question

Vehicle: 2018 Acura TLX A-Spec

My 2018 Acura TLX A-Spec keeps having its battery die if I leave it parked for more than a day. I've had the battery tested, and it seems fine, less than a year old. It's really frustrating to wake up to a dead car.

I've checked for lights left on, but everything seems off. Could it be a parasitic draw? What should I even look for? This just started happening a few weeks ago, and I'm at a loss.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 4:57 AM

0

ClearTheCode admin answer:

Battery drain, especially on a relatively new battery, often points to a parasitic draw. This means something in your vehicle is still consuming power even when the car is off. Here's how to approach it:

  1. Verify the Battery & Charging System: Even if the battery tested 'good,' ensure your alternator is charging correctly. A weak alternator can lead to undercharging, mimicking a drain. Most auto parts stores can test both for free.
  2. Check for Obvious Culprits:
    • Glove box light, trunk light, or under-hood light staying on.
    • Aftermarket accessories (stereo, alarm, dash cam) wired incorrectly.
    • Faulty door switches that don't register the door as closed.
  3. Perform a Parasitic Draw Test:
    • You'll need a multimeter. Connect it in series between the negative battery post and the negative battery cable (after disconnecting the cable).
    • Wait for all modules to 'go to sleep' (this can take 15-30 minutes). A normal draw is usually under 50 milliamps (0.05 amps).
    • If the draw is high, start pulling fuses one by one while watching the multimeter. When the draw drops significantly, you've found the circuit causing the issue.

Common Causes of Parasitic Draw in Acuras:

  • Faulty infotainment system modules.
  • Stuck relays (e.g., for the HVAC blower).
  • Door lock actuators or window motors.
  • Navigation or telematics units.

When to See a Shop: If you're uncomfortable performing a parasitic draw test or can't pinpoint the circuit, it's best to visit a qualified mechanic or an Acura dealership. They have specialized diagnostic tools to identify module faults and trace complex electrical issues. Ignoring a parasitic draw can lead to premature battery failure and leave you stranded.

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