TECH TIP: Checking Battery Connections

Condition: A number of electrical service issues on some GM trucks and SUVs could stem from a vehicle’s battery condition or its connections.
Vehicles Involved:  2015-2020 Tahoe, Suburban, Yukon and Escalade; 2014-2018 Silverado and Sierra; and 2019 Silverado LD, Sierra Limited, and Silverado and Sierra 2500/3500
When to check the battery: Carefully examine a vehicle’s battery if you or your customer have experienced any of the following:

  • Blank instrument cluster or radio
  • Service StabiliTrak message with warning chime
  • Hood ajar message or flashing dome lights when shifting into Reverse
  • Alarm sounds when locking doors
  • Blank HVAC
  • Reduced power steering assist
  • Windshield wipers that continue to run after being turned off
Any of these conditions may be caused by one of four battery issues:

1. This condition may be caused by battery cables with high resistance and/or loose connections at the positive or negative battery cables or battery fuse block

Correction for high resistance cables :
  • Perform a loaded voltage drop test on the short positive battery cable If the voltage drop is above 100 mV, replace the affected cable.
  • Perform a loaded voltage drop test on the negative battery cable. If the voltage drop is above 200 mV, replace the affected cable

2. A poor BCM ground at G218

  • Check for the front of dash insulator mat (2) being trapped between the ground eyelet and the body/stud

3. A shorted B+ battery cable at the starter solenoid caused by a loose starter shield contacting the starter battery cable terminal ring, or a starter cable ring terminal that was incorrectly installed or rotated on the starter solenoid  

  • Inspect the starter solenoid B+ battery cable for possible contact at the starter heat shield  or a loose shield resting on terminal

4. Discharged or faulty battery  

  • Perform the "Battery Inspection/Test"

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