Ignition Off Draw Test

The term Ignition OFF Draw (IOD) identifies a normal condition where power is being drained from the battery with the ignition switch in the OFF position. A normal vehicle electrical system will draw up to 30 milliamperes (0.030 ampere) with the ignition switch in the OFF position, and all non-ignition controlled circuits in proper working order. Up to 30 mA are needed to enable the memory functions for the Powertrain Control Module (PCM), Body Control Module (BCM), electronically tuned radio, and other modules which may vary with the vehicle equipment.

Excessive IOD can be caused by:

• Electrical items left on
• Inoperative or improperly adjusted switches
• Inoperative or shorted electronic modules and components
• Intermittent shorts in the wiring
• An internally shorted generator

If the IOD is over 30 milliamperes, the problem must be found and corrected before replacing a battery. In most cases, the battery can be charged and returned to service after the excessive IOD condition has been corrected.

1. Verify that all electrical accessories are OFF. Turn OFF all lamps, remove the ignition key, and close all doors. If the vehicle is equipped with an illuminated entry system or an electronically tuned radio, allow the electronic timer function of these systems to shut OFF (time out).
2. Determine that the under hood lamp is operating properly, then disconnect the lamp wire harness connector, remove the lamp bulb or put a weight on the hood ajar switch/switches to turn off the under hood lamp.
3. If a battery or fuse box is located inside the vehicle requiring a door or tailgate to be open in order to access the battery, use a screwdriver to close the door latch without closing the door to allow the vehicle to enter sleep mode.
   NOTE:

   It may be best to put something between the open door and vehicle to avoid someone trying to close the door and possibly damaging the latch.

4. Disconnect and isolate the negative battery cable. If equipped with an Intelligent Battery Sensor (IBS), disconnect the IBS connector first before disconnecting the negative battery cable.
   NOTE:

   If equipped, disconnect the negative side of the Auxiliary Battery. This must be disconnected for the duration of the test.