QuestionI wound up with a dead battery today, I have recharged it and it seems to be holding a charge 13 volts. When the car is running checking again about 14.1 volts. I think the Alternator is good and the battery seems OK. How do I check for a draw?
AnswerBATTERY IGNITION OFF DRAW (IOD)
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 milliampere meter.
Verify that all electrical accessories are OFF.
Remove key from ignition switch
Turn off all lights
Trunk lid 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
CAUTION: Always disconnect the milliampere meter before opening a door.
Using an multi-meter, 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. 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.
Each time the 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.
Remove the PDC fuses:
Interior lamps
Brake lamp
IOD
If there is any reading, with fuses removed there is a short circuit in the wiring. Refer to wiring diagrams. Repair as necessary. If reading is less than 25 mA go to Step 8.
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 Step 9. If not, disconnect:
Radio
Body control module
Remote keyless entry module
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. Refer to for wiring diagrams and circuit information.
Remove interior and brake lamp fuses. Install the fuses. The milliampere reading should be 2-4 mA. If reading is higher than 4 mA:
Disconnect PCM.
If reading is OK, replace PCM.
If reading does not change, disconnect the TCM.
If reading is OK, replace TCM.
If reading stays, there is a short circuit to one of the modules. Refer to Wiring Diagrams.
