Jeep Grand Cherokee WK. Manual - part 649

*DIAGNOSIS AND CHECKOUT PROCEDURE FOR SEAT WEIGHT SENSORS (CONTINUED)

VERIFY COMPLAINT

Turn the ignition off.

Move the front passenger seat to the full rear position. Verify that the seat is empty, the seat back is in the normal
upright position, and that the seat is not interfering with any interior components.

Verify that all related connectors are properly seated and locked.

Turn the ignition on.

With the scan tool in OCM, select Data Display and note the Passenger Seat Weight Sensor voltage for all four
sensors (Left Front, Right Front, Left Rear and Right Rear).

Move the front passenger seat to the mid track position.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors.

Move the front passenger seat to the full forward position.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.4 to 3.6 volts for each sensor in each position (full rear, mid track, and full forward).

Is any sensor’s voltage reading out of the acceptable range in any position?

Yes

>> Go To 2

>> Perform test B1BA7 Occupant Classification System Verification Required. If the test passes, the seat

weight sensing system is working properly. Return to the procedure that directed you to this procedure.

CHECKING FOR BENT FLOOR PAN

Turn the ignition off.

Loosen all of the mounting screws retaining the front passenger seat to the vehicle crossmembers, but do not
remove them. Verify that the seat is loose and that no binding exists between the seat and the crossmembers.

Move the front passenger seat to the full rear position and then to the full forward position.

Tighten all of the mounting screws to specification. Refer to 23 - BODY/SEATS.

Move the front passenger seat to the full rear position.

Turn the ignition on.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors.

Move the front passenger seat to the mid track position.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors.

Move the front passenger seat to the full forward position.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.4 to 3.6 volts for each sensor in each position.

Is any sensor’s voltage reading out of the acceptable range in any position?

Yes

>> Go To 3

>> Perform test B1BA7 Occupant Classification System Verification Required. If the test passes, the seat

weight sensing system is working properly. Return to the procedure that directed you to this procedure.

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RESTRAINTS - ELECTRICAL DIAGNOSTICS

*DIAGNOSIS AND CHECKOUT PROCEDURE FOR SEAT WEIGHT SENSORS (CONTINUED)

CHECKING SEAT TO RISER STRESS

Turn the ignition off.

Loosen all of the mounting screws retaining the front passenger seat track to the riser, but do not remove them.
Verify that the seat track is loose and that no binding exists between the seat track and the risers.

Turn the ignition on.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.5 to 3.5 volts for each sensor.

Is any sensor’s voltage reading out of the acceptable range?

Yes

>> Go To 4

>> Visually inspect for damaged or bent risers and crossmembers. Also, verify that the riser holes line up

with the seat mounts in the crossmembers.

If riser damage is apparent, replace the risers in accordance with the Service Information. Then, reinstall
the Seat Weight Sensors, and Go To 6.

NOTE: Failure to follow test instructions or aborting the test will cause faults to set when performing the
Occupant Classification Module System Verification Test. To prevent faults due to process errors: Verify
That All Tests Steps That Led You Here Were Performed As Directed; Verify That The Ignition Is In Run; Wait
30 Seconds After Changing The Seat Weight Before Proceeding To Allow The System To Stabilize; Only
Press Scan Tool Buttons When Directed To Do So; & Perform The Occupant Classification Module System
Verification Test To Completion.

If crossmember or floorpan damage is present, repair or replace the components as necessary in accor-
dance with the Service Information. Reinstall the seat in the vehicle in accordance with the Service
Information. Turn the ignition on. With the scan tool in OCM, select More Options, select System Tests,
and select Occupant Classification Module System Verification Test. Run the test by following the direc-
tions displayed on the scan tool. When the test is complete, Go To 1.

TEST SEAT FRAME

Turn the ignition off.

Remove the front passenger seat from the risers in accordance with the Service Information. Return the risers to
their normal mounting position.

Turn the ignition on.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.4 to 3.6 volts for each sensor.

Is any sensor’s voltage reading out of the acceptable range?

Yes

>> Go To 5

>> Visually inspect for damaged or bent risers, a damaged or bent seat and seat structure, and damaged

or bent seat tracks. Also, verify that the holes in the center of the sensors line up with the seat track
holes and that the seat track position locating tabs are locked in the same parallel slots. If riser damage
is apparent, replace the risers in accordance with the Service Information. Then, reinstall the Seat
Weight Sensors, and Go To 6.

If seat or seat track damage is present, replace the components as necessary in accordance with the
Service Information. Then, Go To 7

RESTRAINTS - ELECTRICAL DIAGNOSTICS

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*DIAGNOSIS AND CHECKOUT PROCEDURE FOR SEAT WEIGHT SENSORS (CONTINUED)

TEST SENSOR

Turn the ignition off.

Loosen the mounting screws of all of the Seat Weight Sensors, but do not remove them. Verify that the sensors are
loose and that no binding exists between the sensors and the risers.

Turn the ignition on.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.4 to 3.6 volts for each sensor.

Is any sensor’s voltage reading out of the acceptable range?

Yes

>> Replace any Seat Weight Sensors that have an unacceptable voltage reading in accordance with the

Service Information. Then, Go To 6.

>> Replace the risers in accordance with the Service Information. Then, reinstall the Seat Weight Sensors,

and Go To 6

CHECKING FOR IMPROPER SEAT WEIGHT SENSOR TORQUE

Turn the ignition off.

Tighten all of the Seat Weight Sensor mounting screws to specification. Refer to 23 - BODY/SEATS.

Turn the ignition on.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.4 to 3.6 volts for each sensor.

Is any sensor’s voltage reading out of the acceptable range?

Yes

>> Loosen the mounting screws of all Seat Weight Sensors with an unacceptable voltage reading, and

repeat Steps 5 and 6.

>> Go To 7

TEST SEAT TRACKS

Turn the ignition off.

Mount the front passenger seat on the risers in accordance with service information.

Turn the ignition on.

Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be
from 1.4 to 3.6 volts for each sensor.

Is any sensor’s voltage reading out of the acceptable range?

Yes

>> Replace the seat track in accordance with the Service Information. Verify that no binding exists between

the seat and risers. Then, repeat Steps 6 and 7.

Reinstall the seat in the vehicle in accordance with the Service Information. Turn the ignition on. With
the scan tool in OCM, select More Options, select System Tests, and select Occupant Classification
Module System Verification Test. Run the test by following the instructions displayed by the scan tool.
When the test is complete, Go To 1

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RESTRAINTS - ELECTRICAL DIAGNOSTICS

*OCS VERIFICATION TEST - VER 1

RESTRAINTS - ELECTRICAL DIAGNOSTICS

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