No power after replacing main battery?

2019 JEEP WRANGLER
97,460 MILES • 3.6L • V6 • 4WD • AUTOMATIC
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DAMON COLLIER
  • MEMBER
  • 1 POST
I have zero power after replacing main battery and disconnecting aux battery after it died yesterday.
May 27, 2025 at 3:50 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi,

Today's technology can be a headache. There is an intelligent battery sensor (IBS) on the battery connection. See pic 1 below. Disconnect that for about a minute and reconnect to see if that resolves the issue.

The IBS has a built-in thermistor that calculates the battery temperature. The microprocessor uses this data to calculate the battery's State of Charge (SOC), internal resistance, charge received, electrical demand, and time in service. This information is reported through the LIN Bus circuit to the Body Control Module (BCM).

What I believe is happening is the BCM thinks the battery is below the threshold, and it's allowing the vehicle to start. If you disconnect the IBS, it should reset to 80% charge.

Try this and let us know if it helps.

Take care,

Joe

See pic below.
May 27, 2025 at 8:32 PM
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