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2020 Audi Q5 Battery Drain - Parasitic Draw Mystery

0

Mike T. · rep 0 · May 22, 4:26 AM · 1 replies · solved · Question

Vehicle: 2020 Audi Q5 Premium

Hi all,

My 2020 Audi Q5 Premium has been having intermittent battery drain issues. Sometimes, after sitting for just a day or two, the battery is completely dead, and I need a jump start. Other times, it's fine for a week. It's really unpredictable and frustrating.

I've had the battery tested, and it's supposedly good. I'm suspecting a parasitic draw, but I'm not sure how to track it down. Has anyone else with a 2020 Q5 or similar model experienced this? What could be causing it?

I'm worried about getting stranded, and it's becoming a real hassle. Any advice on what modules or systems might be staying awake and draining the battery?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 4:26 AM

0

ClearTheCode admin answer:

A parasitic battery drain on a 2020 Audi Q5 can be a challenging issue to diagnose due to the complexity of modern vehicle electrical systems. Intermittent drains are particularly tricky. Here's a systematic approach:

  1. Verify Battery and Charging System: Even if the battery tested 'good,' ensure the alternator is charging correctly (typically 13.8-14.5 volts when running) and that the battery itself doesn't have an internal short that only manifests under certain conditions. A load test is more thorough than a simple voltage check.
  2. Measure Parasitic Draw:
    • Connect a multimeter in series between the negative battery post and the negative battery cable (ensure the car is off and all doors are closed, and wait for all modules to 'sleep' – this can take 20-60 minutes).
    • A normal draw should be around 20-50 milliamps (0.02-0.05 amps). Anything significantly higher indicates a problem.
  3. Fuse Pull Method: Once you've confirmed a high draw, start pulling fuses one by one while monitoring the multimeter. When the amperage drops significantly, you've identified the circuit causing the draw. This will narrow down the problematic module or component.
  4. Common Culprits: For Audis, common sources of parasitic draw include:
    • MMI/Infotainment System: A module not shutting down properly.
    • Comfort Control Module (CCM): Issues with door locks, windows, or interior lights.
    • Gateway Module: Can sometimes stay awake.
    • Aftermarket Accessories: Anything added to the car (dash cams, alarms, etc.) can be a source.
    • Faulty Alternator Diode: Can cause a slow drain.
    • Keyless Entry System: A faulty sensor or module can prevent it from sleeping.

OBD Codes: While a parasitic draw itself doesn't always trigger a specific OBD code, a low battery voltage can lead to codes like P0562 (System Voltage Low) or U0100 (Lost Communication with ECM/PCM 'A') if modules lose power during operation.

When to See a Shop: If you're uncomfortable performing electrical diagnostics or can't pinpoint the source, it's highly recommended to take your Q5 to an Audi dealership or a specialist. They have advanced diagnostic tools that can monitor module sleep states and identify specific components drawing excessive power, saving you time and potential frustration.

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