1994 JEEP CHEROKEE relay

net complete one revolution. Sensor signals are sent
to the transmission control module.
The park/neutral position switch is mounted on the
valve body manual shaft. The switch signals shift
linkage and manual valve position to the transmis-
sion control module through an interconnecting har-
ness. The switch prevents engine starting in all gears
other than Park or Neutral.
The brake switch is in circuit with the torque con-
verter clutch solenoid. The switch disengages the
converter clutch whenever the brakes are applied.
The switch is mounted on the brake pedal bracket
and signals the transmission control module when
the pedal is pressed or released.
TORQUE CONVERTER
A four element torque converter is used for all ap-
plications. The converter consists of the front cover
and pump, stator, turbine, and an electronic modu-
lated converter clutch mechanism.
The converter clutch mechanism consists of a slid-
ing clutch piston, clutch springs and the clutch disc
material (Fig. 4). The clutch provides optimum
torque transfer and economy when engaged.
The clutch disc is attached to the converter front
cover. The clutch piston and clutch springs are at-
tached to the turbine hub. The springs dampen en-
gine firing impulses and loads during the initial
phase of converter clutch engagement.
Clutch engagement is controlled by transmission
valve body solenoid number three and by the con-
verter clutch relay valve. The solenoid channels line
pressure to the clutch through the relay valve at
clutch engagement speeds.
Torque converter clutch engagement occurs in sec-
ond gear in 1-2 position; third gear in 3 position and
third and fourth gear in D position.
FOURTH GEAR OVERDRIVE COMPONENTS
The overdrive system consists of the input shaft, one-
way clutch, planetary sun gear, ring gear, planetary car-
rier, direct clutch and overdrive brake (Fig. 5). The
overdrive elements are controlled and applied through
transmission valve body solenoid number two.
In overdrive fourth gear, the brake prevents the
overdrive sun gear from turning. During operation,
the overdrive elements operate as follows:
The overdrive input shaft and planetary carrier ro-
tate as a unit. The sun gear and overdrive direct
clutch drum are in mesh and operate as a single
unit. The direct clutch splines function as the hub for
the overdrive brake. The one-way clutch outer race is
in mesh with the planetary carrier. The inner race is
fixed to the sun gear shaft.
Fig. 5 Fourth Gear Overdrive Components
Fig. 4 Torque Converter With Modulated Clutch
21 - 158 AW-4 AUTOMATIC TRANSMISSIONJ

upward exposing the drain port. Excess pressure
then bleeds off as needed. As pressure drops, spring
tension moves the valve downward closing the drain
port.
Converter Clutch Relay Valve
The relay valve (Fig. 17) controls fluid flow to the
converter clutch. The valve is operated by line pres-
sure from the 1-2 shift valve and is controlled by so-
lenoid valve number three.1-2 Shift Valve
The 1-2 shift valve (Fig. 18) controls 1-2 upshifts
and downshifts. The valve is operated by the No. 2
valve body solenoid and line pressure from the man-
ual valve, second coast modulator valve and the 2-3
shift valve.
When the transmission control module deactivates
the solenoid, line pressure at the top of the valve
moves the valve down closing the second brake accu-
mulator feed port. As the solenoid is activated and
Fig. 16 Secondary Regulator Valve
Fig. 18 1-2 Shift Valve
Fig. 17 Converter Clutch Relay Valve
JAW-4 AUTOMATIC TRANSMISSION 21 - 163

(3) Remove valve stop and throttle cam (Fig. 3).(4) Remove throttle valve pin with magnet and re-
move downshift plug, valve spring and throttle valve
(Fig. 4).
(5) Turn upper body over and remove throttle
valve adjusting rings and spring (Fig. 5). Note num-
ber of adjusting rings if valve is equipped with them.
(6) Remove 3-4 shift valve retainer with magnet
and remove valve plug, spring and 3-4 shift valve
(Fig. 6).
(7) Remove second coast modulator valve retainer
and remove valve plug, spring and valve.
(8) Remove lock-up relay valve retainer and re-
move relay valve and sleeve assembly (Fig. 8).
(9) Remove relay valve, spring and plunger from
valve sleeve (Fig. 9).
(10) Remove secondary pressure regulator valve re-
tainer and remove plug, regulator valve and spring
(Fig. 10).
(11) Remove cut-back valve retainer and remove
plug, cut-back valve and spring (Fig. 11).
(12) Remove 2-3 shift valve retainer and remove
plug, spring and 2-3 shift valve (Fig. 12).
(13) Remove low coast modulator valve retainer
and remove valve plug, spring and low coast modula-
tor valve (Fig. 13).
(14) Clean the upper body components with solvent
and dry them with compressed air only. Do not use
shop towels or rags. Lint or foreign material from
towels or rags can interfere with valve operation.
(15) Inspect condition of the upper body compo-
nents. Replace the upper body if any of the bores are
scored or corroded. Replace any valves, plugs or
sleeves if scored or worn. Replace the oil strainer if
cut, torn or damaged in any way.
Fig. 3 Removing/Installing Valve Stop And Throttle Cam
Fig. 4 Removing/Installing Throttle Valve
Fig. 5 Throttle Valve Adjusting Ring Location (If
Equipped)
JAW-4 TRANSMISSION OVERHAUL 21 - 247

Fig. 6 Removing/Installing 3-4 Shift Valve
Fig. 7 Removing/Installing Second Coast Modulator
Valve
Fig. 8 Removing/Installing Converter Clutch Relay
Valve
Fig. 9 Relay Valve Components
21 - 248 AW-4 TRANSMISSION OVERHAULJ

(16) Inspect the valve body springs. Replace any
spring having rusted, distorted, or collapsed coils.
Measure length of each spring. Replace any spring if
free length is less than specified in the chart (Fig.
14).
UPPER BODY ASSEMBLY
(1) Lubricate the valves, springs, plugs, sleeves
and the valve bores in the upper body with automatic
transmission fluid.
(2) Note position of the valve retainers (A) and
stop (B) for assembly reference (Fig. 15).
(3) Install low coast modulator valve, spring and
plug in valve bore. Press valve plug inward and in-
stall retainer (Fig. 13).(4) Install 2-3 shift valve, spring and plug in valve
bore. Press plug inward and install retainer (Fig. 12).
(5) Install cut-back valve spring, valve and plug
(Fig. 11). Press plug inward and install retainer.
(6) Install secondary regulator valve spring, valve
and plug in valve bore. Press plug inward and install
retainer (Fig. 10).
(7) Assemble lock-up relay valve. Install spring
and plunger in valve sleeve (Fig. 9). Then install as-
sembled valve in sleeve.
(8) Install assembled lock-up relay valve in valve
bore and install retainer (Fig. 8).
(9) Install second coast modulator valve, spring
and plug in valve bore. Press plug inward and install
retainer (Fig. 7).
(10) Install 3-4 shift valve, spring and plug in bore.
Press plug inward and install retainer (Fig. 6).
Fig. 14 Upper Body Spring/Valve Identification
21 - 250 AW-4 TRANSMISSION OVERHAULJ

The reinforcement bracket is held on the
frame rail with two blind rivets.
(2) Remove the bracket and tow hook from frame
rail.
INSTALLATION
(1) Position bracket and tow hook on the frame
rail.
(2) Install bolts that attach tow hook bracket to
frame rail and reinforcement bracket. Tighten bolts
to 75 Nzm (55 ft-lbs) torque.
TRAILER HITCHES
CLASS III HITCHÐXJ VEHICLES
A class III weight-distributing/equalizer type hitch
can be used to tow a trailer:
²having a maximum gross weight of 5,000 lbs/2250
kg, and
²having a maximum tongue weight of 750 lbs/332
kg).
The following vehicle basic equipment is required
for class III trailer towing:
²P205/75R15 or larger tires;
²full size spare tire;
²trailer sway control;
²trailer tow wire harness and connector;
²heavy duty turn signal flasher element;
²heavy duty axle (with synthetic lubricant);²heavy duty cooling system;
²heavy duty generator/battery;
²auxiliary automatic transmission fluid cooler; and
²I-6, 4.0L engine.
Wide-angle type door mirrors are recommended but
not required.
WIRE HARNESS CONNECTORS
CLASS I HITCH CONNECTOR
The trailer tow wire harness connector for class I
trailer hitches is a 5-terminal, in-line type connector.
Terminal 5 is the source for vehicle ground.
CLASS III HITCH CONNECTOR
The trailer tow wire harness connector for class III
trailer-tow hitches is a 7-terminal, circular type con-
nector.
The 12-volt circuit for the trailer is protected
from overloads. A auto-reset type circuit
breaker is located in the trailer tow wire har-
ness near the plug-in relays.
CAUTION: The trailer tow wire harness package
does not include a vehicle battery isolator unit. Be-
cause of this, the trailer battery can totally dis-
charge the vehicle battery if the engine is not
operated for an extended period of time.
Fig. 11 Trailer Tow Wire Harness Connectors
23 - 88 BODY COMPONENTSÐXJ VEHICLESJ

A blue wire (without a connector) located under in-
strument panel near fuse panel is available for
trailer electric brake control unit.
The stop lamp and turn signal plug-in relays are
located behind left quarter trim panel.
HITCH REMOVALÐXJ VEHICLES
An XJ class III, weight-distributing/equalizer type
hitch is comprised of:
²a towing tube with a ball mount receptacle, and²various reinforcement/support brackets that are at-
tached to the vehicle frame sills and rear crossmem-
ber with bolts.
(1) If necessary, remove the trailer tow wire har-
ness connector from the hitch.
(2) Support the hitch.
(3) Remove the bolts that attach the towing tube
to the frame sills and reinforcement bracket. If
equipped, remove the fuel tank skid plate.
Fig. 14 Equalizer Type HitchÐXJ Vehicles
Fig. 12 Class III Trailer Tow Wire Harness and
ConnectorsFig. 13 Class III Trailer Tow Wire Harness Plug-In
Relays
JBODY COMPONENTSÐXJ VEHICLES 23 - 89

SERVICE DIAGNOSISÐELECTRICAL
BLOWER CONTROLSÐXJ VEHICLES
DESCRIPTION
The blower motor delivers air to the inside of the
vehicle. Its speed is controlled by the blower switch
and the blower resistors. With the switch in LO, part
of the battery voltage is supplied to the motor
through all of the resistors. The motor runs slowly.
As the blower switch is moved to a higher speed, the
switch allows more voltage to be applied to the
blower motor, which will increase its speed. When
the switch is in HI, the blower resistors are bypassed
and battery voltage is applied directly to the blower
motor. The motor runs at the fastest speed in this
mode.
DIAGNOSIS
Refer to the Group 8W, Wiring Diagrams for com-
plete system schematic.
1. BLOWER MOTOR INOPERATIVE
²Remove and inspect fuse. If the fuse is blown, re-
place fuse.
2. BLOWER MOTOR INOPERATIVE (HI Posi-
tion)
Put the ignition switch in RUN, the select switch
in HEAT and the blower switch on HI.
²Blower motor connector (Terminal A) should be
battery voltage. If not go to next step.
²Blower motor connector (Terminal B) should be 0
ohms. If not, repair wire to ground.
²Blower switch connector (Terminal C) should be
battery voltage. If battery voltage replace blower
switch. If not, replace select switch.
3. BLOWER MOTOR INOPERATIVE (LO, M1
& M2 Positions)
Ignition switch in RUN, select switch in HEAT.
²Blower resistors connector (Terminal D) should be
battery voltage. If not, replace select switch.
²Blower resistors connector (Terminal C) should be
battery voltage. If not, replace blower switch.
²Blower resistors connector (Terminal A) should be
battery voltage. If not, replace blower switch.
²Blower resistors connector (Terminal B) should be
battery voltage. If not, replace blower resistor.
AIR CONDITIONING SYSTEMÐXJ VEHICLES
DESCRIPTION
The A/C Compressor Clutch is belt-driven by the
engine. A clutch, operated by a solenoid, automati-
cally turns the compressor on and off to control evap-
orator icing.
The A/C Compressor Clutch operation is controlled
by several components: the A/C Low-Pressure
Switch, Thermostat Switch, Fuel Pump Relay, A/C
Clutch Relay and the Engine Controller.The A/C low pressure switch opens when there is
not enough refrigerant in the system. When this hap-
pens, voltage is no longer present at the Engine Con-
troller. The Engine Controller will turn off the A/C
clutch relay. With the proper refrigerant level in the
system, the low pressure switch remains closed.
When the evaporator temperature is low enough to
ice the cooling coils, the thermostat switch opens.
The Engine Controller will turn off the A/C clutch.
The thermostat switch closes when the temperature
rises. The Engine Controller will then turn the A/C
clutch relay on again.
DIAGNOSIS
Refer to the Group 8W, Wiring Diagrams for com-
plete system schematic.
With engine running, Engine Controller may delay
A/C clutch up to 30 seconds.
1. A/C COMPRESSOR CLUTCH INOPERA-
TIVE
Clutch connector disconnected.
²Jumper fused test lead, battery to clutch connec-
tor, clutch should operate. If not, replace compressor
clutch assembly.
2. A/C LOW PRESSURE SWITCH
Ignition in RUN, A/C controls in MAX or NORM.
²Low pressure switch connector (Terminal A)
should be battery voltage. If not, repair open to select
switch.
²Low pressure switch connector (Terminal C)
should be battery voltage. If not, check switch resis-
tance and check freon pressure.
3. A/C CLUTCH RELAY
Engine RUNNING, A/C controls in MAX or
NORM.
²Relay connector Pin 4 to ground should be battery
voltage. If not, check fuse F6 in Power Distribution
Center.
²Ground A/C clutch relay (Terminal 5) should have
A/C compressor clutch engagement. If not, check En-
gine Controller Terminals 27, 28 and 34.
HEATING SYSTEMÐYJ VEHICLES
DESCRIPTION
The blower motor circuit begins at a 25 amp fuse
that receives its battery feed from the ignition
switch. From the fuse the circuit extends to a micro-
switch mounted on the heater control.
The micro-switch is normally closed is operated by
a cam on the heater control lever. In all heater con-
trol lever positions, except OFF and VENT, the
blower motor electrical circuit is complete. In the
OFF and VENT positions the cam depresses the mi-
cro-switch lever opening the electrical circuit to the
blower motor.
24 - 14 HEATING AND AIR CONDITIONINGJ