Tools Required
• | J 38758 Parasitic
Draw Test Switch |
Caution: Batteries produce explosive gases. Batteries contain corrosive acid.
Batteries supply levels of electrical current high enough to cause burns.
Therefore, in order to reduce the risk of personal injury while working
near a battery, observe the following guidelines:
• | Always shield your eyes. |
• | Avoid leaning over the battery whenever possible. |
• | Do not expose the battery to open flames or sparks. |
• | Do not allow battery acid to contact the eyes or the skin. |
- | Flush any contacted areas with water immediately and thoroughly. |
Notice: Do not turn the parasitic draw test switch to the OFF position with
the engine running. Damage will occur to the vehicle's electrical system.
Notice: The test switch must be in the ON position when removing the fuses in
order to maintain continuity in the electrical system. This avoids damaging
the digital multimeter due to accidental overloading, such as
a door being opened to change a fuse.
Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing
any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to
the vehicle or its components.
- Disconnect
the battery negative cable.
- Install the male end of
the J 38758
to the negative
battery terminal.
- Turn OFF the test switch.
- Install the negative battery cable to the female end of the test
switch.
- Install the Scan Tool
or equivalent, or wait for 20 minutes.
- Turn ON the test switch.
- Road test the vehicle while activating all the accessories, including
the radio and the air conditioning.
- Lower the door glass, then exit the vehicle. Do not move the door
handle after closing the door.
- Open the hood.
Important: The power down timer will reset to 20 minutes if any wake up inputs
are received by a class 2 device (after the scan tool has put all class 2
devices to sleep).
- Put all of the class 2 devices into the sleep mode.
- Turn OFF the ignition switch. Remove the key.
Important: From this point on, electrical continuity must be maintained in the
ground circuit of the battery through the test switch J 38758
in the ON position or through the ammeter J 39200
.
- Components such as powertrain control module (PCM), vehicle control
module (VCM), air conditioning (A/C), and the body control module (BCM) have
timers that draw several amps of current while cycling down. This can give
a false parasitic drain reading. Wait 20 minutes for these components
to power down before continuing this test (or use the scan tool in order
to put all class 2 devices to sleep).
- Connect a jumper wire with a 10 A fuse J 36169-A
to the terminals of the test switch.
- Turn the test switch to the OFF position.
- Wait 10 seconds.
If the fuse does not blow, the current is less than 10 A.
You can use the ammeter safely.
- Before removing the fused jumper wire, turn the test switch to
the ON position.
- You can detect a high current drain using the following procedure:
Important: If you use an ammeter other than the J 39200
, ensure that the vehicle does not have a high current drain
that would damage the ammeter when connected to the circuit.
- Set the ammeter J 39200
to the 10 A scale.
- Connect the ammeter in order to the test switch terminals.
- Turn OFF the test switch. This allows the current to flow through
the ammeter.
- Wait 1 minute, then inspect the current reading.
• | When there is a current reading of 2 A or less, turn ON
the test switch. This maintains continuity in the electrical system. |
• | Then, switch the meter down to the 2 A scale, for a more
accurate reading, when the test switch reopens. |
- Open the test switch.
- Take the reading in milliamps.
- Note the battery reserve capacity. Refer to
Battery Usage
.
• | Divide this number by 4. Example: 90/4 = 22.5 |
• | Compare this to the ammeter reading. |
• | The current drain in milliamps should not exceed this number. |
• | Example: If a battery has a reserve capacity of 90 minutes, the
current drain should not exceed 22 milliamps. |
- When the current draw is too high, remove the electrical system
fuses 1 at a time until the draw returns to a value less than or equal to
the specifications.
• | Start with the fuses that are hot all the time. |
• | To remove the fuse, you must first open the door, which causes
a high enough current flow to damage the ammeter. |
• | Protect the ammeter, without disturbing the electrical continuity,
by turning ON the test tool before opening the door. |
• | Remove the courtesy lamp fuse. |
• | Note the ammeter reading. |
• | If the parasitic load is still excessive, start removing the remaining
fuses 1 at a time. |
• | Keep the courtesy lamp fuse out during diagnosis, so the door
can remain open. |
• | Perform Steps 11 through 13 each time a fuse is removed. |
- Removing the PCM or the VCM fuse should cause a drop of less than
10 milliamps.
A drop greater than 10 milliamps indicates a possible short to
ground.
- Inspect the orange wires along with the components connected to
the orange wires.
No drop in the milliampere reading indicates the PCM or the VCM is not
drawing current.
- Repeat the parasitic current drain test procedure after any repair
has been completed.
- When the cause of the excessive current draw has been located
and repaired, remove the ammeter and the parasitic draw test switch.
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.
- Connect the battery
negative cable to the negative battery terminal.
Tighten
Tighten the battery negative cable bolt to 17 N·m (13 lb ft).