relay JEEP CHEROKEE 1994 Service Owners Manual

DIAGNOSTIC TROUBLE CODE DESCRIPTIONSÐCONTINUED
Diagnostic
Trouble
CodeDRB Scan Tool
DisplayDescription of Diagnostic Trouble Code
41**..........Generator Field Not
Switching ProperlyAn open or shorted condition detected in the generator field control circuit.
42* ..........Auto Shutdown Relay
Control CircuitAn open or shorted condition detected in the auto shutdown relay circuit.
44* ..........Battery Temp Sensor
Volts out of LimitAn open or shorted condition exists in the engine coolant temperature sensor
circuit or a problem exists in the PCM's battery temperature voltage circuit.
46**..........Charging System Voltage
Too HighBattery voltage sense input above target charging voltage during engine
operation.
47**..........Charging System Voltage
Too LowBattery voltage sense input below target charging during engine operation.
Also, no significant change detected in battery voltage during active test of
generator output.
51**.......... O2SSignal Stays Below
Center (Lean)Oxygen sensor signal input indicates lean air/fuel ratio condition during
engine operation.
52**.......... O2SSignal Stays Above
Center (Rich)Oxygen sensor signal input indicates rich air/fuel ratio condition during
engine operation.
53* ..........Internal PCM Failure PCM Internal fault condition detected.
or
PCM Failure SPI
CommunicationsPCM Internal fault condition detected.
54* .......... NoCamSync Signal at
PCMNo fuel sync (camshaft signal) detected during engine cranking.
55* .......... N/ACompletion of diagnostic trouble code display on the Malfunction Indicator
Lamp (Check Engine Lamp).
62* .......... PCMFailure SPI miles not
storedUnsuccessful attempt to update SPI miles in the PCM EEPROM.
63* .......... PCMFailure EEPROM
Write DeniedUnsuccessful attempt to write to an EEPROM location by the PCM.
* Check Engine Lamp will not illuminate at all times if this Diagnostic Trouble Code was recorded. Cycle Ignition key as
described in manual and observe code flashed by Check Engine lamp.
** Check Engine Lamp will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
JFUEL SYSTEM 14 - 53

MULTI-PORT FUEL INJECTION (MFI)ÐCOMPONENT REMOVAL/INSTALLATION
INDEX
page page
Accelerator Pedal and Throttle Cable......... 54
Air Cleaner Housing...................... 54
Air Conditioning (A/C) Clutch Relay........... 54
Air Filter............................... 54
Automatic Shut Down (ASD) Relay........... 54
Brake Switch............................ 54
Camshaft Position Sensor.................. 54
Crankshaft Position Sensor................. 55
Engine Coolant Temperature Sensor.......... 55
Fuel Filter.............................. 55
Fuel Injector............................ 55
Fuel Pump Module....................... 56
Fuel Pump Relay........................ 56
Fuel Rail Assembly....................... 56
Fuel System Pressure Release Procedure...... 56
Fuel Tank Pressure Relief/Rollover Valve...... 56
Fuel Tanks............................. 56Fuel Tubes/Lines/Hoses and Clamps.......... 56
Idle Air Control (IAC) Motor................. 56
Ignition Coil............................. 57
Intake Air Temperature Sensor.............. 54
Intake Manifold.......................... 57
Manifold Absolute Pressure (MAP) Sensor..... 57
Oxygen (O2S) Sensor..................... 57
Park Neutral Switch....................... 58
Power Steering Pressure SwitchÐ2.5L
Engine Only........................... 58
Powertrain Control Module (PCM)............ 58
Quick-Connect Fittings..................... 59
Throttle Body............................ 59
Throttle Position Sensor (TPS).............. 59
Torque Converter Clutch Relay.............. 60
Vehicle Speed Sensor..................... 60
ACCELERATOR PEDAL AND THROTTLE CABLE
Refer to the Accelerator Pedal and Throttle Cable
section of this group for removal/installation proce-
dures.
AIR CONDITIONING (A/C) CLUTCH RELAY
The A/C clutch relay is located in the Power Dis-
tribution Center (PDC) (Figs. 1 or 2). For location of
this relay within the PDC, refer to label on PDC
cover.
AIR CLEANER HOUSING
Refer to Group 25, Emission Control System.
AIR FILTER
Refer to Group 25, Emission Control System.
AUTOMATIC SHUT DOWN (ASD) RELAY
The ASD relay is located in the Power Distribution
Center (Figs. 1 or 2) (PDC). For location of this relay
within the PDC, refer to label on PDC cover.
BRAKE SWITCH
Refer to Group 5, Brakes for removal/installation
procedures.
CAMSHAFT POSITION SENSOR
For removal/installation procedures, refer to Group
8D, Ignition System. See Camshaft Position Sensor.
INTAKE AIR TEMPERATURE SENSOR
The intake manifold air temperature sensor is in-
stalled into the intake manifold plenum (Figs. 3 or
4).
Fig. 1 PDCÐYJ Models
Fig. 2 PDCÐXJ Models
14 - 54 FUEL SYSTEMJ

INSTALLATION
(1) Install the fuel injector(s) into the fuel rail as-
sembly and install retaining clip(s).
(2) Install fuel rail. Refer to Fuel Rail Installation
in this section.
(3) Start engine and check for fuel leaks.
FUEL PUMP MODULE
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.
FUEL PUMP RELAY
The Fuel Pump relay is located in the Power Dis-
tribution Center (PDC) (Figs. 1 or 2). For location of
this relay within the PDC, refer to label on PDC
cover.
FUEL RAIL ASSEMBLY
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT FUEL PRESSURE (EVEN WITH THE ENGINE
OFF) OF APPROXIMATELY 131-269 KPA (19-39
PSI). THIS PRESSURE MUST BE RELEASED BE-
FORE SERVICING THE FUEL RAIL.
(1) Remove fuel tank filler tube cap.
(2) Disconnect the negative battery cable from bat-
tery.
(3) Perform the Fuel System Pressure Release Pro-
cedure as described in the Fuel Delivery System sec-
tion of this Group.
(4) Remove and numerically attach a tag (if fuel
injector is not already tagged), the injector harness
connectors. Do this at each injector (Fig. 7).
(5) Disconnect vacuum line from fuel pressure reg-
ulator (Fig. 7).
(6) Disconnect fuel supply line from fuel rail and
the fuel return line from fuel pressure regulator (Fig.7). Refer to Fuel Tubes/Lines/Hoses and Clamps, or
Quick-Connect Fittings. These can both be found in
the Fuel Delivery section of this group.
(7) Remove fuel rail mounting bolts.
On models with automatic transmissions, it may be
necessary to remove automatic transmission throttle
line pressure cable (and bracket). This will aid in fuel
rail assembly removal.
(8) Remove fuel rail by gently rocking until all the
fuel injectors are out of the intake manifold.
INSTALLATION
(1) Position tips of all fuel injectors into the corre-
sponding injector bore in the intake manifold. Seat
injectors into manifold.
(2) Tighten fuel rail mounting bolts to 27 Nzm (20
ft. lbs.) torque.
(3) Connect injector harness connectors to appro-
priate (tagged) injector.
(4) Connect both fuel lines to fuel rail.
(5) Connect vacuum supply line to fuel pressure
regulator.
(6) Install protective cap to pressure test port fit-
ting.
(7) Install fuel tank cap.
(8) Connect negative battery cable to battery.
(9) Start engine and check for fuel leaks.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF)
OF APPROXIMATELY 100 KPA (14.5 PSI). BEFORE
SERVICING THE FUEL PUMP, FUEL LINES, FUEL
FILTER OR FUEL INJECTOR, THE FUEL SYSTEM
PRESSURE MUST BE RELEASED.
Refer to the Fuel Delivery System section of this
group. See Fuel Pressure Release procedure.
FUEL TANKS
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TANK PRESSURE RELIEF/ROLLOVER VALVE
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TUBES/LINES/HOSES AND CLAMPS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures. Also refer
to Quick-Connect Fittings in the Fuel Delivery sec-
tion of this group.
IDLE AIR CONTROL (IAC) MOTOR
The IAC motor is mounted to the throttle body ad-
jacent to the throttle position sensor (Fig. 8).
Fig. 7 Fuel Injector HarnessÐTypical
14 - 56 FUEL SYSTEMJ

the sensor will not rotate, install the sensor with the
throttle shaft on the other side of the socket tangs).
The TPS will be under slight tension when rotated.
(1) Install the TPS and retaining bolts.
(2) Connect TPS electrical connector to TPS.
(3) Manually operate the throttle (by hand) to
check for any TPS binding before starting the en-
gine.
TORQUE CONVERTER CLUTCH RELAY
On YJ models, the TCC relay is located in the en-
gine compartment. It is attached to the cowl panel
with one bolt (Fig. 20). On XJ models, the TCC relay
is located in the power distribution center (PDC)
(Fig. 21). For location of this relay within the PDC,
refer to label on PDC cover.
VEHICLE SPEED SENSOR
The vehicle speed sensor (Fig. 22) is located on the
extension housing of the transmission on 2WD mod-
els. It is located on the transfer case on 4WD models.
REMOVAL
(1) Raise and support vehicle.
(2) Disconnect the electrical connector from the
sensor.
(3) Remove the sensor mounting bolt (Fig. 23).
Fig. 18 TPS LocationÐ4.0L Engine
Fig. 19 Throttle Position SensorÐInstallation
Fig. 20 TCC Relay LocationÐYJ Models
Fig. 21 Power Distribution CenterÐXJ Models
Fig. 22 Vehicle Speed Sensor LocationÐTypical
14 - 60 FUEL SYSTEMJ

controlled by throttle pressure, which is dependent
on the degree of throttle opening.
The governor valve is operated by the transmission
output shaft. Governor pressure increases in propor-
tion to vehicle speed.
The throttle valve determines line pressure and
shift speed. The throttle valve also controls upshift
and downshift speeds by regulating pressure in con-
junction with throttle position.
Shift Valves
The manual valve is operated by the gearshift link-
age and provides the operating range selected by the
driver.
The 1-2 shift valve provides automatic 1-2 or 2-1
shifts and the 2-3 shift valve provides automatic 2-3
or 3-2 shifts. The kickdown valve provides forced 3-2
or 3-1 downshifts depending on vehicle speed. Down-
shifts occur when the throttle is opened beyond
downshift detent position which is just before wide
open throttle.
The 2-3 valve throttle pressure plug provides 3-2
downshifts with varying throttle openings and de-
pending on vehicle speed. The 1-2 shift control valve
transmits 1-2 shift pressure to the accumulator pis-
ton to control kickdown band capacity on 1-2 upshifts
and 3-2 downshifts.The shuttle valve has two functions. First is fast
front band release and smooth engagement during
lift-foot 2-3 upshifts. The second is to regulate front
clutch and band application during 3-2 downshifts.
Clutches-Bands-Servos-Accumulator
The front/rear clutch pistons and servo pistons are
actuated by line pressure. When line pressure is re-
moved, the pistons are released by spring tension.
On 2-3 upshifts, the front servo piston is released
by spring tension and hydraulic pressure. The accu-
mulator controls hydraulic pressure on the apply side
of the front servo during 1-2 upshifts and at all
throttle openings.
Converter Clutch Controls
Converter clutch operation is controlled by the
power train control module, and by the solenoid and
clutch module on the valve body. The solenoid is op-
erated by a relay on the engine compartment side of
the dash panel.
Activating the solenoid opens a vent allowing fluid
to flow into the clutch module. When line pressure
exceeds tension of the module valve springs, the
module valves open. This allows fluid to be chan-
neled to the converter clutch through the reaction
shaft support and transmission shaft.
Gearshift And Parking Lock Controls
The gearshift lever provides six operating posi-
tions: Park (P), Reverse (R), Neutral (N), and the D,
2 and 1 forward drive ranges.
Manual 1 position provides first gear only. Overrun
braking occurs in 1 range when the throttle is re-
leased. Upshifts are not provided in 1 range.
Manual 2 range provides first and second gear. A
1-2 upshift will take place but a 2-3 upshift will not
occur.
D position provides 1-2, 2-3 upshifts and 3-2 and
3-1 downshifts.
Park position allows the park rod to move the park
pawl into engagement with the park gear. This pre-
vents rotation of the transmission output shaft. The
park lock mechanism is only engaged when the shift
lever is in the Park detent.
A park/neutral position switch controls engine
starting. The switch is designed to allow engine
starts only in park or neutral positions.
Fig. 2 Transmission Identification
21 - 68 30RH/32RH AUTOMATIC TRANSMISSIONJ

The valve body solenoids are controlled by signals
from the transmission control module (TCM). Signal
sequence is determined by vehicle speed and throttle
position.
Fourth gear is an 0.75:1 ratio overdrive range.
First, second, third and reverse gear are conventional
ranges. Third gear ratio is 1:1. A separate planetary
gear set provides overdrive operation in fourth gear.
TRANSMISSION RANGES AND SHIFT LEVER
POSITIONS
The AW-4 transmission has six ranges and shift le-
ver positions. Park, Reverse and Neutral are conven-
tional and mechanically operated. The 1-2, 3 and D
ranges provide electronically controlled shifting.
The 1-2 position provides first and second gear
only. The 3 position provides first, second and third
gear.
The D range provides first through fourth gear.
Overdrive fourth gear range is available only when
the shift lever is in D position (Fig. 2).
TRANSMISSION IDENTIFICATION
The transmission I.D. plate is attached to the case
(Fig. 3). The plate contains the transmission serial
and model numbers. Refer to the information on this
plate when ordering service parts.
COMPONENTS AND OPERATION
ELECTRONIC CONTROLS
The AW-4 is electronically controlled in the 1, 2, 3
and D ranges. Controls consist of the transmission
control module (TCM), valve body solenoids and var-ious sensors. The sensors monitor vehicle speed,
throttle opening, shift lever position and brake pedal
application.
TRANSMISSION CONTROL MODULE (TCM)
The module determines shift and converter clutch
engagement timing based on signals from the sen-
sors. The valve body solenoids are activated, or deac-
tivated accordingly.
The module has a self diagnostic program. Compo-
nent and circuitry malfunctions can be diagnosed
with the DRB II scan tool. Once a malfunction is
noted and stored in control module memory, it is re-
tained even after the problem has been corrected. To
cancel a stored malfunction, simply disconnect and
reconnect the9Trans.9fuse in the module harness.
TRANSMISSION VALVE BODY SOLENOIDS
The solenoids are mounted on the valve body and
operated by the transmission control module. The so-
lenoids control operation of the converter clutch and
shift valves in response to input signals from the
module.
SENSORS
The sensors include the throttle position sensor
(TPS), transmission output speed sensor, vehicle
speed sensor, park/neutral position switch and brake
switch.
The throttle position sensor is mounted on the
throttle body. It electronically determines throttle po-
sition and relays this information to the transmission
control module to determine shift points and con-
verter clutch engagement.
The transmission speed sensor consists of a rotor
and magnet on the transmission output shaft and a
switch in the extension housing or adapter. The sen-
sor switch is activated each time the rotor and mag-
Fig. 2 AW-4 Shift Lever Positions And Transmission
Ranges
Fig. 3 Transmission Identification
JAW-4 AUTOMATIC TRANSMISSION 21 - 157

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