1. A fault in the ignition switch which keep the modules awake
2. A fault in the theft deterrent system that again could keep the modules from going into sleep mode
3. A fault with an individual module
A factory scan tool (Tech 2) can be used to help diagnosis this concern. I am sure that the dealer technician will be able to find the root cause although it can be challenging as often these faults are intermittent.
How can I make sure my car sleeps at night?
Wheels: Joseph owns a vehicle that is under warranty and therefore is only being inconvenienced with this problem. What could an owner of an older vehicle do to check for a battery drain?
Halderman: Many of the faults that can drain a battery can be checked by the owner. Items to check include:
• Check to see that the glove box door is fully closed to make sure that the light is off.
• Check that the sun visors are in the up position.
• Disconnect a cell phone charger.
If all of these items are OK, then ask a professional service technician to perform a battery drain (parasitic draw) test to find the root cause.
James D. Halderman is an ASE-certified master technician, a member of the Society of Automotive Engineers and the author of 12 textbooks. Send questions to jhalderman2@juno.com or Wheels, Marketing Publications Department, Dayton Daily News, 1611 S. Main St., Dayton OH 45409.
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