The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2018 Pacifica Touring L - Battery Draining Overnight, No Obvious Culprit

0

Sarah K. · rep 0 · May 22, 5:54 AM · 1 replies · solved · Question

Vehicle: 2018 Chrysler Pacifica Touring L

Hey everyone,

I'm having a really frustrating issue with my 2018 Chrysler Pacifica Touring L. For the past few weeks, the battery keeps dying overnight, or sometimes even after just sitting for a few hours. It's completely dead, no lights, no nothing. I've had to jump it multiple times.

I replaced the battery about six months ago, thinking that was the problem, but it's happening again. I've checked to make sure all the lights are off, doors are closed, and nothing is left plugged into the USB ports. The Uconnect screen sometimes stays on for a bit after I turn off the car, but it eventually goes dark. Could that be it?

I don't have any aftermarket accessories installed, just the factory setup. No check engine light or other warning lights are coming on before it dies. Has anyone else experienced this with their Pacifica? Any ideas on what I should check next before I take it to the dealership?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 5:54 AM

0

ClearTheCode admin answer:

It sounds like your 2018 Chrysler Pacifica is experiencing a parasitic battery drain, which is a common but often tricky electrical issue. This means something is drawing power even when the vehicle is off. Here's a breakdown of potential causes and diagnostic steps:

Common Causes of Parasitic Drain in Chrysler Pacificas (2016-2026):

  • Uconnect System: The Uconnect infotainment system is a frequent culprit. A software glitch or a faulty module can prevent it from fully shutting down, leading to a constant draw. This can sometimes manifest as the screen staying on longer than usual or the system attempting to update.
  • Body Control Module (BCM): The BCM controls many electrical functions. A malfunctioning BCM can fail to put various systems to sleep, causing a drain.
  • Faulty Relays or Fuses: A stuck relay or a short in a circuit can keep a component active.
  • Door Latch Assemblies: Issues with door latch sensors can sometimes prevent the vehicle from entering its 'sleep' mode, as it thinks a door is ajar.
  • Liftgate Module: Similar to door latches, a faulty liftgate module might keep the system awake.
  • Alternator Diode Failure: A failing diode in the alternator can allow current to flow from the battery back into the alternator when the engine is off, effectively draining the battery.

Diagnostic Steps You Can Take:

  1. Battery Health Check: Even if it's relatively new, have your battery professionally tested to ensure it's holding a charge correctly and isn't defective. Also, check the battery terminals and cables for corrosion or looseness.
  2. Test for Parasitic Draw:
    • Ensure the vehicle has been off for at least 30 minutes (allowing all modules to 'sleep').
    • Disconnect the negative battery terminal.
    • Connect a multimeter in series between the negative battery post and the disconnected negative battery cable (set to amperage mode, typically 10A or 20A range). The reading should ideally be below 50mA (0.05A) after about 15-30 minutes.
    • If the draw is high, start pulling fuses one by one from the fuse box (both under the hood and inside the cabin) while monitoring the multimeter. When the amperage drops significantly, you've identified the circuit causing the drain.
  3. Check for Diagnostic Trouble Codes (DTCs): Even without a check engine light, a professional scan tool might reveal stored codes related to low voltage (e.g., P0562 - System Voltage Low) or specific module communication issues that could point to the problem.

When to See a Shop:

If you're uncomfortable performing the parasitic draw test, or if you've identified a circuit but can't pinpoint the exact component (e.g., the Uconnect system or BCM), it's best to take your Pacifica to a qualified technician or a Chrysler dealership. They have specialized diagnostic tools that can communicate with individual modules, perform software updates, and more accurately diagnose complex electrical issues. Addressing this promptly will prevent further battery damage and ensure reliable operation of your vehicle.

Menu

Help & account