14 volt relay JEEP GRAND CHEROKEE 2002 WJ / 2.G Repair Manual

RIGHT FRONT SIDE MARKER LAMP (EXCEPT BUILT-UP-EXPORT) - WHITE 2 WAY
CAV CIRCUIT FUNCTION
1 L7 20BK/PK PARK LAMP RELAY OUTPUT
2 L60 20TN RIGHT TURN SIGNAL
RIGHT FRONT TURN SIGNAL LAMP (BUILT-UP-EXPORT) - WHITE 2 WAY
CAV CIRCUIT FUNCTION
1 L60 20TN RIGHT TURN SIGNAL
2 Z1 18BK GROUND
RIGHT FRONT WHEEL SPEED SENSOR - GRAY 2 WAY
CAV CIRCUIT FUNCTION
1 B7 18WT RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT
SUPPLY
2 B6 18WT/DB RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
RIGHT HEADLAMP LEVELING MOTOR (BUILT-UP-EXPORT) - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 Z1 18BK GROUND
2 L114 18VT/DB HEADLAMP ADJUST SIGNAL
3 L7 20BK/PK PARK LAMP RELAY OUTPUT
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 115

RIGHT REAR DOOR LOCK MOTOR/AJAR SWITCH - BLACK 4 WAY
CAV CIRCUIT FUNCTION
1 G76 18TN/YL RIGHT REAR DOOR AJAR SWITCH SENSE
2 Z1 18BK GROUND
3 P36 18PK/VT DOOR UNLOCK DRIVER
4 P35 18OR/VT DOOR LOCK DRIVER
RIGHT REAR DOOR SPEAKER - WHITE 3 WAY
CAV CIRCUIT FUNCTION
1 X52 18WT/VT (BASE) RIGHT REAR DOOR SPEAKER (+)
1 X90 18WT/VT (PREMIUM) RIGHT REAR DOOR SPEAKER (+)
2- -
3 X58 18TN/DG (BASE) RIGHT REAR DOOR SPEAKER (-)
3 X92 18TN/DG (PREMIUM) RIGHT REAR DOOR SPEAKER (-)
RIGHT REAR LAMP ASSEMBLY - BLACK 6 WAY
CAV CIRCUIT FUNCTION
1 L1 18VT/BK BACK-UP LAMP FEED
2 L95 18DG/YL (BUILT-UP-EXPORT) REAR FOG LAMP RELAY OUTPUT
3 L7 18BK/YL PARK LAMP RELAY OUTPUT
4 L62 18BR/RD RIGHT TURN SIGNAL
5 Z151 18BK GROUND
6 L50 18WT/TN PRIMARY BRAKE SWITCH SIGNAL
RIGHT REAR WHEEL SPEED SENSOR - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 B2 18YL RIGHT REAR WHEEL SPEED SENSOR 12 VOLT
SUPPLY
2 B1 18YL/DB RIGHT REAR WHEEL SPEED SENSOR SIGNAL
RIGHT REMOTE RADIO SWITCH - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 X10 20RD/BK RADIO CONTROL MUX RETURN
2 X20 20RD/YL RADIO CONTROL MUX
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 117

TEMPERATURE VALVE ACTUATOR (MTC) - BLACK 6 WAY
CAV CIRCUIT FUNCTION
5- -
6- -
7 Z132 20BK/OR GROUND
8 C67 20RD/LB BLEND AIR DOOR POSITION CONTROL
9- -
10 F22 20WT/PK FUSED IGNITION SWITCH OUTPUT (RUN)
THROTTLE POSITION SENSOR (4.0L) - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 K7 18OR 5 VOLT SUPPLY
2 K4 18BK/LB SENSOR GROUND
3 K22 18OR/RD THROTTLE POSITION SENSOR SIGNAL
THROTTLE POSITION SENSOR (4.7L)-3WAY
CAV CIRCUIT FUNCTION
1 K7 18OR 5 VOLT SUPPLY
2 K22 18OR/RD THROTTLE POSITION SENSOR SIGNAL
3 K4 18BK/LB SENSOR GROUND
TRAILER TOW BRAKE LAMP RELAY - BLACK 5 WAY
CAV CIRCUIT FUNCTION
30 (3) F9 14RD/BK FUSED B(+)
85 (2) L50 18WT/TN PRIMARY BRAKE SWITCH SIGNAL
86 (1) Z150 18BK GROUND
87 (5) L95 14DG/YL TRAILER TOW BRAKE LAMP RELAY OUTPUT
87A
(4)L94 14OR/WT TRAILER TOW BRAKE LAMP RELAY OUTPUT
TRAILER TOW CIRCUIT BREAKER - BLACK 2 WAY
CAV CIRCUIT FUNCTION
A F30 14RD/WT FUSED CIGAR LIGHTER RELAY OUTPUT
B F30 14RD/TN CIGAR LIGHTER RELAY OUTPUT
8W - 80 - 122 8W-80 CONNECTOR PIN-OUTWJ

TRANSMISSION CONTROL MODULE (4.7L) - BLACK 60 WAY
CAV CIRCUIT FUNCTION
1 T1 18LG/BK TRS T1 SENSE
2 T2 18TN/BK TRS T2 SENSE
3 T3 18VT TRS T3 SENSE
4- -
5- -
6 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
7 D21 18PK SCI TRANSMIT
8 F45 18YL/RD FUSED IGNITION SWITCH OUTPUT (START)
9 T9 18OR/BK OVERDRIVE PRESSURE SWITCH SENSE
10 T10 18YL/DG TORQUE MANAGEMENT REQUEST SENSE
11 F991 18OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 K22 18OR/RD THROTTLE POSITION SENSOR SIGNAL
13 T13 18DB/BK SPEED SENSOR GROUND
14 T14 18LG/WT OUTPUT SPEED SENSOR SIGNAL
15 K30 18PK/YL TRANSMISSION CONTROL RELAY CONTROL
16 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
17 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
18 T118 18YL/DB PRESSURE CONTROL SOLENOID CONTROL
19 T119 18WT/DB 2C SOLENOID CONTROL
20 T120 18LG LR SOLENOID CONTROL
21 - -
22 - -
23 - -
24 - -
25 - -
26 - -
27 - -
28 - -
29 T29 18GY UNDERDRIVE PRESSURE SWITCH SENSE
30 T130 14VT/TN LINE PRESSURE SENSOR SIGNAL
31 - -
32 - -
33 - -
34 - -
35 - -
36 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
37 Z113 14BK/WT GROUND
38 T138 14GY/LB 5 VOLT SUPPLY
39 Z112 14BK/YL GROUND
40 T140 18VT/LG MS SOLENOID CONTROL
41 T41 18WT TRS T41 SENSE
42 T42 18VT/WT TRS T42 SENSE
43 D25 18YL/VT PCI BUS
44 - -
45 - -
46 D20 18LG SCI RECEIVE
47 T147 18LB 2C PRESSURE SWITCH SENSE
48 T48 18DB 4C PRESSURE SWITCH SENSE
49 T6 18VT/WT OVERDRIVE OFF SWITCH SENSE
50 T150 18BR/LB LR PRESSURE SWITCH SENSE
51 K4 18BK/LB SENSOR GROUND
52 T52 18RD/BK INPUT SPEED SENSOR SIGNAL
53 Z114 14BK/LG GROUND
54 T54 18VT TRANSMISSION TEMPERATURE SENSOR SIGNAL
55 T59 18PK UNDERDRIVE SOLENOID CONTROL
56 A30 14RD/WT FUSED B(+)
57 Z12 14BK/TN GROUND
58 - -
59 T159 18DG/WT 4C SOLENOID CONTROL
60 T60 18BR OVERDRIVE SOLENOID CONTROL
8W - 80 - 124 8W-80 CONNECTOR PIN-OUTWJ

TRANSMISSION CONTROL MODULE C1 (DIESEL) - BLACK 18 WAY
CAV CIRCUIT FUNCTION
1 D21 20PK SCI TRANSMIT
2- -
3 W4 20PK/OR SHIFTER C5 SENSE
4 Y1 20DB/PK PARK LOCKOUT SOLENOID CONTROL
5- -
6- -
7 T41 20BK/WT PARK/NEUTRAL POSITION SWITCH SENSE (T41)
8- -
9- -
10 - -
23 - -
24 - -
25 W0 20DB/WT SHIFTER C1 SENSE
26 W1 20VT/WT SHIFTER C2 SENSE
27 W2 20VT SHIFTER C3 SENSE
28 W3 20BK SHIFTER C4 SENSE
29 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
30 Z234 20WT GROUND
TRANSMISSION CONTROL MODULE C2 (DIESEL) - BLACK 14 WAY
CAV CIRCUIT FUNCTION
12 T52 18RD/BK N2 INPUT SPEED SENSOR
13 T39 18GY/LB SENSOR SUPPLY VOLTAGE
14 T60 18BR 1-2/4-5 SOLENOID CONTROL
15 T159 18DG/WT 3-4 SOLENOID CONTROL
16 T119 18WT/DB 2-3 SOLENOID CONTROL
17 T120 18LG TCC SOLENOID CONTROL
33 T13 18DB/BK SENSOR GROUND
34 T54 18VT TEMP SENSOR - P/N SWITCH
35 T14 18LG/WT N3 INPUT SPEED SENSOR
36 T591 18YL/DB MODULATION PRESSURE SOLENOID CONTROL
37 T118 18YL/DB SHIFT PRESSURE SOLENOID CONTROL
38 T16 18RD SOLENOID SUPPLY VOLTAGE
H1 D52 18LG/WT CAN C BUS(+)
L2 D51 18DG/WT CAN C BUS(-)
TRANSMISSION SOLENOID (4.0L) - BLACK 8 WAY
CAV CIRCUIT FUNCTION
1 T15 18LG FUSED TRANSMISSION CONTROL RELAY OUTPUT
2 K6 18VT/BK 5 VOLT SUPPLY
3 K4 18BK/LB SENSOR GROUND
4 T25 18LG/RD GOVERNOR PRESSURE SENSOR SIGNAL
5 K88 18PK GOVERNOR PRESSURE SOLENOID CONTROL
6 T60 18BR 3-4 SHIFT SOLENOID CONTROL
7 T20 18LB TORQUE CONVERTER CLUTCH SOLENOID CONTROL
8 T54 18VT TRANSMISSION TEMPERATURE SENSOR SIGNAL
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 125

TRANSMISSION SOLENOID ASSEMBLY (DIESEL) - BLACK 13 WAY
CAV CIRCUIT FUNCTION
1 T14 18LG/WT N3 INPUT SPED SENSOR
2 T591 18YL/DB MODULATION PRESSURE SOLENOID CONTROL
3 T52 18RD/BK N2 INPUT SPEED SENSOR
4 T54 18VT TEMP SENSOR - P/N SWITCH
5- -
6 T16 18RD SOLENOID SUPPLY VOLTAGE
7 T39 18GY/LB SENSOR SUPPLY VOLTAGE
8 T119 18WT/DB 2-3 SOLENOID CONTROL
9 T159 18DG/WT 3-4 SOLENOID CONTROL
10 T118 18YL/DB SHIFT PRESSURE SOLENOID CONTROL
11 T120 18LG TCC SOLENOID CONTROL
12 T13 18DB/BK SENSOR GROUND
13 T60 18BR 1-2/4-5 SOLENOID CONTROL
TRANSMISSION SOLENOID/TRS ASSEMBLY (4.7L) - GRAY 23 WAY
CAV CIRCUIT FUNCTION
1 F22 18WT/PK FUSED IGNITION SWITCH OUTPUT (RUN)
2 T120 18LG LR SOLENOID CONTROL
3 T41 18BK/WT PARK/NEUTRAL POSITION SWITCH SENSE (T41)
4 T141 18WT TRS T41 SENSE
5 T42 18VT/WT TRS T42 SENSE
6 L1 18VT/BK BACK-UP LAMP FEED
7 T60 18BR OVERDRIVE SOLENOID CONTROL
8 T3 18VT TRS T3 SENSE
9 T1 18LG/BK TRS T1 SENSE
10 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
11 T48 18DB 4C PRESSURE SWITCH SENSE
12 T118 18YL/DB PRESSURE CONTROL SOLENOID CONTROL
13 T2 18TN/BK TRS T2 SENSE
14 T150 18BR/LB LR PRESSURE SWITCH SENSE
15 T147 18LB 2C PRESSURE SWITCH SENSE
16 T9 18OR/BK OVERDRIVE PRESSURE SWITCH SENSE
17 T59 18PK UNDERDRIVE SOLENOID CONTROL
18 T29 18GY UNDERDRIVE PRESSURE SWITCH SENSE
19 T159 18DG/WT 4C SOLENOID CONTROL
20 T119 18WT/DB 2C SOLENOID CONTROL
21 T140 18VT/LG MS SOLENOID CONTROL
22 T13 18DB/BK SPEED SENSOR GROUND
23 T54 18VT TRANSMISSION TEMPERATURE SENSOR SIGNAL
UNDERHOOD LAMP - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 Z141 20BK GROUND
2 M1 20PK/RD FUSED B(+)
8W - 80 - 126 8W-80 CONNECTOR PIN-OUTWJ

of the preparation procedures performed just prior to
new vehicle delivery.
The PDC has a molded plastic cover that can be
removed to provide service access to all of the fuses
and relays in the PDC. An integral latch and hinges
are molded into the PDC cover for easy removal. A
fuse layout map is integral to the underside of the
PDC cover to ensure proper fuse and relay identifica-
tion. The IOD fuse is a 50 ampere maxi-type car-
tridge fuse and, when removed, it is stored in a spare
fuse cavity within the PDC.
OPERATION
The term ignition-off draw identifies a normal con-
dition where power is being drained from the battery
with the ignition switch in the Off position. The IOD
fuse feeds the memory and sleep mode functions for
some of the electronic modules in the vehicle as well
as various other accessories that require battery cur-
rent when the ignition switch is in the Off position,
including the clock. The only reason the IOD fuse is
removed is to reduce the normal IOD of the vehicle
electrical system during new vehicle transportation
and pre-delivery storage to reduce battery depletion,
while still allowing vehicle operation so that the
vehicle can be loaded, unloaded and moved as needed
by both vehicle transportation company and dealer
personnel.
The IOD fuse is removed from PDC fuse cavity 15
when the vehicle is shipped from the assembly plant.
Dealer personnel must install the IOD fuse when the
vehicle is being prepared for delivery in order to
restore full electrical system operation. Once the
vehicle is prepared for delivery, the IOD function of
this fuse becomes transparent and the fuse that has
been assigned the IOD designation becomes only
another Fused B(+) circuit fuse. The IOD fuse serves
no useful purpose to the dealer technician in the ser-
vice or diagnosis of any vehicle system or condition,
other than the same purpose as that of any other
standard circuit protection device.
The IOD fuse can be used by the vehicle owner as
a convenient means of reducing battery depletion
when a vehicle is to be stored for periods not toexceed about thirty days. However, it must be
remembered that removing the IOD fuse will not
eliminate IOD, but only reduce this normal condition.
If a vehicle will be stored for more than about thirty
days, the battery negative cable should be discon-
nected to eliminate normal IOD; and, the battery
should be tested and recharged at regular intervals
during the vehicle storage period to prevent the bat-
tery from becoming discharged or damaged. Refer to
Battery Systemfor additional service information.
REMOVAL
The Ignition-Off Draw (IOD) fuses normal installa-
tion location is cavity 15 in the power distribution
center. When the vehicle is shipped from the assem-
bly plant the fuse is removed to maintain proper bat-
tery voltage during vehicle storage (in some cases).
Dealer personnel must install the IOD fuse when the
vehicle is being prepared for customer delivery in
order to restore full electrical system operation.
(1) Turn the ignition switch to the Off position.
(2) Unlatch and open the cover of the power distri-
bution center.
(3) Remove the IOD fuse from fusecavity 15of
the power distribution center (Fig. 2).
(4) Store the removed IOD fuse by installing it in
the unused fuse storagecavity 11of the PDC (Fig.
2).
(5) Close and latch the power distribution center
cover.
INSTALLATION
(1) Be certain the ignition switch is in the Off posi-
tion.
(2) Unlatch and open the cover of the power distri-
bution center.
(3) Remove the stored IOD fuse from fuse storage
cavity 11of the power distribution center.
(4) Use a thumb to press the IOD fuse firmly down
into power distribution center fusecavity 15.
(5) Close and latch the power distribution center
cover.
8W - 97 - 4 8W-97 POWER DISTRIBUTIONWJ
IOD FUSE (Continued)

outlet receptacle and a good ground. There should be
continuity. If OK, go to Step 4. If not OK, go to Step
5.
(4) Check for battery voltage at the insulated con-
tact located at the back of the power outlet recepta-
cle. If not OK, go to Step 5.
(5) Disconnect and isolate the battery negative
cable. Remove the instrument panel center lower
bezel. Check for continuity between the ground cir-
cuit cavity of the power outlet wire harness connector
and a good ground. There should be continuity. If
OK, go to Step 6. If not OK, repair the open ground
circuit to ground as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
power outlet wire harness connector. If OK, replace
the faulty power outlet receptacle. If not OK, repair
the open fused B(+) circuit to the junction block fuse
as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center lower bezel from the instru-
ment panel. Refer toInstrument Panel Center
Lower Bezelin Body for the procedure.
(3) Pull the cigar lighter knob and element or the
protective cap out of the cigar lighter receptacle base,
or open the power outlet door in the instrument
panel center lower bezel.
(4) Look inside the cigar lighter or power outlet
receptacle base and note the position of the rectangu-
lar retaining bosses of the mount that secures the
receptacle base to the instrument panel center lower
bezel (Fig. 15).
(5) Insert a pair of external snap ring pliers into
the cigar lighter or power outlet receptacle base and
engage the tips of the pliers with the retaining
bosses of the mount.
(6) Squeeze the pliers to disengage the mount
retaining bosses from the receptacle base and, using
a gentle rocking motion, pull the pliers and the
receptacle base out of the mount.
(7) Remove the cigar lighter or power outlet mount
from the instrument panel center lower bezel.
INSTALLATION
(1) Install the cigar lighter or power outlet mount
into the instrument panel center lower bezel.
(2) Align the splines on the outside of the cigar
lighter or power outlet receptacle base connector
receptacle with the grooves on the inside of the
mount.
(3) Press firmly on the cigar lighter or power out-
let receptacle base until the retaining bosses of the
mount are fully engaged in their receptacles.(4) Install the cigar lighter knob and element or
the protective cap into the cigar lighter receptacle
base, or close the power outlet door in the instrument
panel center lower bezel.
(5) Install the center lower bezel onto the instru-
ment panel. Refer toInstrument Panel Center
Lower Bezelin Body for the procedure.
(6) Reconnect the battery negative cable.
POWER OUTLET RELAY
DESCRIPTION
The power outlet / cigar lighter relay is an electro-
mechanical device that switches fused battery cur-
rent to the cigar lighter or power outlet when the
ignition switch is turned to the Accessory or On posi-
tions. The power outlet / cigar lighter relay is located
in the junction block, below the driver side of the
instrument panel in the passenger compartment.
The cigar lighter relay is a International Standards
Organization (ISO) relay. Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions.
Fig. 15 Cigar Lighter and Power Outlet Remove/
Install - Typical
1 - KNOB AND ELEMENT
2 - RETAINING BOSSES-ENGAGE PLIERS HERE
3 - BASE
4 - PARTIALLY REMOVED
5 - EXTERNAL SNAP-RING PLIERS
6 - MOUNT
7 - BASE
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 13
POWER OUTLET (Continued)

The cigar lighter relay cannot be repaired or
adjusted and, if faulty or damaged, it must be
replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor or diode, and three (two fixed and one mov-
able) electrical contacts. The movable (common feed)
relay contact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact.
When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor or diode is con-
nected in parallel with the electromagnetic coil in the
relay, and helps to dissipate voltage spikes that are
produced when the coil is de-energized.
DIAGNOSIS AND TESTING - POWER OUTLET
RELAY
The power outlet / cigar lighter relay (Fig. 16) is
located in the junction block, below the driver side
end of the instrument panel in the passenger com-
partment. For complete circuit diagrams, refer to
Horn/Cigar Lighter/Power Outletin Wiring Dia-
grams.
WARNING: REFER TO RESTRAINTS BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Remove the power outlet / cigar lighter relay
from the junction block. Refer to the procedure in
this group.
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, perform the Relay Circuit Test that
follows. If not OK, replace the faulty relay.
DIAGNOSIS AND TESTING - RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) of
the junction block is connected to battery voltage and
should be hot at all times. Check for battery voltage
at the fused B(+) circuit cavity in the junction block
receptacle for the cigar lighter relay. If OK, go to
Step 2. If not OK, repair the fused B(+) circuit to the
Power Distribution Center (PDC) fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the fused B(+) fuse in the junction block that feeds
the cigar lighter when the relay is energized by the
ignition switch. There should be continuity between
the junction block cavity for relay terminal 87 and
the fused B(+) fuse in the junction block at all times.
If OK, go to Step 4. If not OK, repair the open fused
B(+) circuit to the junction block fuse as required.
(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. It receives battery
feed to energize the cigar lighter relay when the igni-
tion switch is in the Accessory or On positions. Turn
the ignition switch to the On position. Check for bat-
tery voltage at the fused ignition switch output (acc/
run) circuit cavity for relay terminal 85 in the
junction block receptacle for the cigar lighter relay. If
OK, go to Step 5. If not OK, repair the open fused
ignition switch output (acc/run) circuit to the ignition
switch as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. The junction block
cavity for this terminal should have continuity to
Fig. 16 Accessory Relay
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
8W - 97 - 14 8W-97 POWER DISTRIBUTIONWJ
POWER OUTLET RELAY (Continued)

OPERATION
Voltage to operate the electric pump is supplied
through the fuel pump relay.
Fuel is drawn in through a filter at the bottom of
the module and pushed through the electric motor
gearset to the pump outlet.
Check Valve Operation:The pump outlet con-
tains a one-way check valve to prevent fuel flow back
into the tank and to maintain fuel supply line pres-
sure (engine warm) when pump is not operational. It
is also used to keep the fuel supply line full of gaso-
line when pump is not operational. After the vehicle
has cooled down, fuel pressure may drop to 0 psi
(cold fluid contracts), but liquid gasoline will remain
in fuel supply line between the check valve and fuel
injectors.Fuel pressure that has dropped to 0
psi on a cooled down vehicle (engine off) is a
normal condition.Refer to the Fuel Pressure Leak
Down Test for more information.
The electric fuel pump is not a separate, service-
able component.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - FUEL PUMP
CAPACITY TEST
Before performing this test, verify fuel pump
pressure. Refer to Fuel Pump Pressure Test.
Use this test in conjunction with the Fuel Pres-
sure Leak Down Test.
(1) Release fuel system pressure. Refer to Fuel
Pressure Release Procedure.
(2) Disconnect fuel supply line at fuel rail. Refer to
Quick-Connect Fittings. Some engines may require
air cleaner housing removal before line disconnection.
(3) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16º fuel
lines and tool number 6631 is used for 3/8º fuel lines.
(4) Connect correct Fuel Line Pressure Test
Adapter Tool Hose into disconnected fuel supply line.
Insert other end of Adaptor Tool Hose into a gradu-
ated container.
(5) Remove fuel fill cap.
(6) To activate fuel pump and pressurize system,
obtain DRBtscan tool and actuate ASD Fuel System
Test.
(7) A good fuel pump will deliver at least 1/4 liter
of fuel in 7 seconds. Do not operate fuel pump for
longer than 7 seconds with fuel line disconnected as
fuel pump module reservoir may run empty.
(a) If capacity is lower than specification, but
fuel pump can be heard operating through fuel fill
cap opening, check for a kinked/damaged fuel sup-
ply line somewhere between fuel rail and fuel
pump module.(b) If line is not kinked/damaged, and fuel pres-
sure is OK, but capacity is low, replace fuel filter/
fuel pressure regulator. The filter/regulator may be
serviced separately on certain applications. Refer
to Fuel Filter/Fuel Pressure Regulator Removal/In-
stallation for additional information.
(c) If both fuel pressure and capacity are low,
replace fuel pump module assembly. Refer to Fuel
Pump Module Removal/Installation.
DIAGNOSIS AND TESTING - FUEL PUMP
AMPERAGE TEST
This amperage (current draw) test is to be done in
conjunction with the Fuel Pump Pressure Test, Fuel
Pump Capacity Test and Fuel Pressure Leak Down
Test. Before performing the amperage test, be sure
the temperature of the fuel tank is above 50É F (10É
C).
The DRBtScan Tool along with the DRB Low Cur-
rent Shunt (LCS) adapter (Fig. 8) and its test leads
will be used to check fuel pump amperage specifica-
tions.
(1) Be sure fuel tank contains fuel before starting
test. If tank is empty or near empty, amperage read-
ings will be incorrect.
(2) Obtain LCS adapter.
(3) Plug cable from LCS adapter into DRB scan
tool at SET 1 receptacle.
(4) Plug DRB into vehicle 16±way connector (data
link connector).
Fig. 8 LOW CURRENT SHUNT
1 - LOW CURRENT SHUNT ADAPTER
2 - PLUG TO DRB
3 - TEST LEAD RECEPTACLES
WJFUEL DELIVERY 14 - 9
FUEL PUMP (Continued)