Ignition Off Draw (IOD) Tests

High current draw on the battery with the ignition OFF will discharge a battery After a dead battery is serviced the vehicle Ignition Off Draw (IOD) should be checked. Determine if a high current draw condition exists first check the vehicle with a test lamp.
1. Verify that all electrical accessories are OFF.
- Remove key from ignition switch
- Turn off all lights
- Liftgate and glove box door is closed
- Sun visor vanity lights are OFF
- All doors are closed
- Allow the Illuminated Entry System to time out in approximately 30 seconds, if equipped.
- During Transmission Control Module (TCM) power down there will be 500 milliamperes present for 20 minutes. Afterwards less than 1.0 milliampere.

Disconnect Battery Negative Cable:

2. Disconnect battery negative cable.

Milliampere Meter Connection:

3. Using an multimeter, that has least a milliampere range of 200 mA. Set meter to the highest mA range. Install meter between the battery negative cable and battery negative post. Carefully remove the test lamp without disconnecting the meter. After all modules time-out the total vehicle IOD should be less than 25 milliamperes. If ignition off draw is more than 25 milliamperes go to Step 4.
4. Each time the test lamp or milliampere meter is disconnected and connected, all electronic timer functions will be activated for approximately one minute. The Body Control Module (BCM) ignition off draw can reach 90 milliamperes.
5. Remove the Power Distribution Center (PDC) fuses:
- Interior lamps
- Brake lamp
- IOD
6. If there is any reading, with fuses removed there is a short circuit in the wiring. If reading is less than 25 mA go to Step 8.
7. Install all fuses. After installing fuse, the current can reach 90 mA. After time-out the reading should not exceed 25 mA. If OK go to. If not, disconnect:
- Radio
- Body Control Module
- Remote Keyless Entry Module
8. Disconnect one component at time, to see if any component is at fault. If the high reading is not eliminated there is a short circuit in the wiring.
9. Remove interior and brake lamp fuses. Install the fuses. The milliampere reading should be 2 - 4 mA. If reading is higher than 4 mA:
a. Disconnect Powertrain Control Module (PCM).
b. If reading is OK, replace PCM.
c. If reading does not change, disconnect the TCM.
d. If reading is OK, replace TCM.
e. If reading stays, there is a short circuit to one of the modules.