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2021 G70 2.0T Battery Draining Overnight - Parasitic Draw?

0

Mike T. · rep 0 · May 25, 4:34 AM · 1 replies · solved · Question

Vehicle: 2021 Genesis G70 2.0T RWD

Hi all,

I'm having a frustrating issue with my 2021 Genesis G70 2.0T RWD. For the past week, if I leave it parked overnight, the battery is completely dead in the morning. I've had to jump-start it multiple times.

I just replaced the battery, thinking it was old, but the new one is doing the exact same thing. This points to a parasitic draw, but I'm not sure how to track it down. There are no lights left on, and all accessories seem to be off.

Has anyone else with a G70 experienced a mysterious battery drain? What are the common culprits for parasitic draws on these cars? Any advice on how to test for this effectively would be a lifesaver!

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 4:34 AM

0

ClearTheCode admin answer:

A persistent battery drain, even with a new battery, on your 2021 Genesis G70 2.0T strongly indicates a parasitic draw. This means something in the car is drawing power even when the vehicle is off and locked. Modern cars have many modules that can cause this.

Here's how to approach diagnosing a parasitic draw and common culprits:

  1. Perform a Parasitic Draw Test:
    • Ensure the car has been off for at least 30 minutes to allow all modules to 'sleep'.
    • Disconnect the negative battery terminal.
    • Connect a multimeter in series between the negative battery post and the negative battery cable (set to Amps, 10A or higher range).
    • Note the initial reading; it will be high, then should drop significantly (ideally below 50mA, though some modern cars can be up to 70-80mA).
    • If the draw remains high (e.g., several hundred mA or Amps), proceed to the next step.
  2. Isolate the Circuit:
    • While monitoring the multimeter, systematically pull one fuse at a time from the fuse boxes (both under the hood and inside the cabin). Watch for a significant drop in the amperage reading. When the current drops, you've identified the circuit causing the draw.
  3. Common Culprits for Parasitic Draws:
    • Infotainment/Navigation System: A module that fails to shut down properly.
    • Aftermarket Accessories: Anything installed after the factory (e.g., alarm, stereo, dash cam) can be a source if wired incorrectly.
    • Alternator: A faulty diode in the alternator can cause a small draw. Disconnect the alternator's main power wire (B+ terminal) and re-check the draw.
    • Glove Box/Trunk Lights: Ensure these lights are turning off when closed.
    • Body Control Module (BCM): A malfunctioning BCM can keep other modules awake.
    • Relays: A stuck relay can keep a circuit energized.

When to See a Shop:

  • If you're uncomfortable performing electrical tests, as improper use of a multimeter can damage it or the vehicle's electronics.
  • If you've identified a circuit but cannot pinpoint the specific component within that circuit.
  • If the draw is intermittent, making it hard to catch.
  • A professional can use more advanced diagnostic tools to identify specific modules that are not entering sleep mode, making diagnosis more efficient.
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