Tools Required
J 38758 Parasitic Load
Test Switch
Notice: The parasitic load test switch should never be turned to the "OFF"
position with the engine running; damage could occur to the attached
ammeter or the vehicle electrical system.
- Remove the battery cable from the battery negative terminal.
- Install the parasitic load test switch male end to the negative
battery terminal.
Tighten
Tighten the J 38758
to 15 N·m (11 lb ft).
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Turn the test switch knob to the off position.
- Install the negative battery cable to the female end of the test
switch tool.
Tighten
Tighten the negative battery cable to 15 N·m (11 lb ft).
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Turn the test switch knob on the ON position.
- Open the trunk in order to access the rear compartment fuse block.
- Turn the ignition switch to the LOCK position and remove the ignition
key.
- Connect the DMM terminals on the test switch tool.
- Turn the test switch tool knob to the OFF position to allow current
to flow through the ammeter.
- After 20 minutes check the current reading. If the current draw
is above 30 millilamps the load can either be that a module on the Class
2 serial data line is not going to "sleep" or that the load
is related to a traditional excessive current draw such as lumbar seat
switch stuck on.
Diagnosing Class 2 Serial Data Line
- Pull the COMFORT, IGN0 BODY, and BATT fuse(s). If the draw goes
away the most likely cause is that a module on the Class 2 serial data line
is keeping the body control module (BCM) "awake." Do not replace
the BCM until the whole test is complete. If the current draw does not
go away, refer to the traditional excessive current draw in this procedure.
- Reinstall the COMFORT fuse. This will "wake up" the
Class 2 serial data line.
- Wait 20 minutes.
- When the BCM goes back to sleep, monitor the current draw using
a DMM. If the current draw is excessive, the cause of the parasitic drain
can be isolated to a component that receives power from the COMFORT fuse
or a component that is powered by the controlled power relay. If no change
is noted in the current draw, proceed to the next step.
- Disconnect the RFA module.
- Monitor the current draw using a DMM. If the excessive current
draw is removed, then the parasitic drain can be isolated to the RFA module
and its related circuits.
- Disconnect the CD changer, if equipped.
- Monitor the current draw using a DMM. If the excessive current
draw is removed, then the parasitic drain can be isolated to the CD changer
and its related circuits.
- Disconnect the ACM.
- Wait 20 minutes.
- When the BCM goes back to sleep, monitor the current draw using
a DMM. If the current draw is excessive, the cause of the parasitic drain
can be isolated to the BCM and its related circuits.
- Do not replace the BCM until all of the components powered by
the controlled power relay have been diagnosed.
- Reinstall the IGN0 BODY fuse (equipped with a climate control
panel CCP).
- Monitor the current draw using a DMM. If the current draw is excessive,
the cause of the parasitic drain can be isolated to a component that receives
power from the IGN0 BODY fuse. If no change is noted in the current draw,
proceed to the next step.
- Reinstall the BATT fuse.
- Monitor the current draw using a DMM. If the current draw is excessive,
the cause of the parasitic drain can be isolated to a component that receives
power from the BATT fuse. If no change is noted in the current draw, proceed
to the next step.
- When cause of excessive current draw has been located and repaired,
remove the parasitic load test switch and connect the negative battery cable
to the negative battery terminal.
Tighten
Tighten the negative battery cable to 15 N·m (11 lb ft).
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
Traditional Excessive Current Draw
- When current draw is above 30 millilamps, remove the system fuses
one fuse at a time until the current draw returns to a value less than or
equal to 30 millilamps.
- Repeat the parasitic current drain procedure after any repair
has been completed.
- When the cause of excessive current draw has been located and
repaired, remove current drain test tool and connect the negative battery
cable to the negative battery terminal.
Tighten
Tighten the negative battery cable to 15 N·m (11 lb ft).
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.