located in power distribution center at driver's side front corner of
engine compartment, near the battery. Automatic Shutdown (ASD) relay
may also be referred to as Auto Shutdown (ASD) relay.
Battery Temperature Sensor
Battery temperature sensor delivers input signal to
Powertrain Control Module (PCM) to indicate the battery temperature.
PCM uses battery temperature input to modify rate of output from the
charging system. Battery temperature sensor is snapped into battery
tray below driver's side battery.
Battery Voltage
Battery voltage input signal provides operating voltage to
Powertrain Control Module (PCM). This input signal keeps PCM memory
alive and informs PCM what generator output voltage is when engine is
running. PCM memory is used to store Diagnostic Trouble Codes (DTCs),
store APPS sensor voltages from previous key cycles and provide a
speed control adaptive memory.
Brake Switch
Brake switch delivers input signal to Powertrain Control
Module (PCM) to indicate when brakes are applied. PCM uses input
signal for controlling cruise control system and transmission torque
converter clutch operation on A/T models. Brake switch is located near
top of brake pedal and may also be referred to as brakelight switch.
CKP Sensor
Crankshaft Position (CKP) sensor delivers input signal (35
tooth wheel with gap) to Engine Control Module (ECM) to indicate
engine speed and crankshaft position. ECM uses CKP signal along with
other input signals for controlling injector firing sequence and
timing. Sensor is located below fuel transfer pump, on side of engine
block. See Fig. 2.
Cruise Control System Switches
Cruise control system functions, controlled by momentary
contact switches, are monitored through multiplexed input signal to
Powertrain Control Module (PCM). Resistance monitored at this input
signal, in conjunction with the length of time the PCM measures the
resistance, determines which switch feature has been selected.
Data Link Connector (DLC)
Data Link Connector (DLC) provides an input signal to
Powertrain Control Module (PCM) when using scan tool to retrieve
Diagnostic Trouble Codes (DTCs) from PCM. Input signal may also be
used when performing various tests on the PCM and electronic control
system. DLC is a 16-pin connector located at lower edge of driver's
side of instrument panel, just above accelerator pedal.
Fuel Level Sensor
The Powertrain Control Module (PCM) sends a 5-volt signal to
the fuel level sensor. The fuel level sensor will return a signal to
PCM. This signal is used for fuel gauge operation and to prevent
setting a false misfire or fuel system trouble codes. If fuel level is
less than 15 percent, PCM will not set code.
Ignition Sense
Ignition switch position input to Powertrain Control Module
(PCM). PCM uses input to determine proper output functions, including
cruise control, generator output, sensor supply and transmission
functions.
Transmission Speed Sensor (A/T Models)
Transmission speed sensor may also be referred to as
transmission output shaft speed sensor. Transmission speed sensor is
located on overdrive case at rear of transmission. Transmission speed
sensor delivers input signal to Powertrain Control Module (PCM) to
indicate transmission output shaft speed.
Overdrive Switch (A/T Models)
Transmission overdrive switch may be referred to as
overdrive/override switch, OD switch or overdrive off switch.
Transmission overdrive switch is located on end of gearshift lever.
When vehicle operator depresses transmission overdrive switch, an
input signal is delivered to the Powertrain Control Module (PCM). The
PCM uses input signal for controlling transmission overdrive shifts by
use of transmission overdrive solenoid on transmission valve body.
Transmission overdrive switch is normally in the ON position, allowing
transmission overdrive operation. If transmission overdrive switch is
depressed once, switch is in OFF position, allowing no transmission
overdrive upshift. If transmission overdrive switch is depressed
again, switch returns to the ON position, allowing transmission
overdrive operation.
Park/Neutral Switch (A/T Models)
Park/neutral switch delivers input signal to Powertrain
Control Module (PCM) to indicate if transmission is in Park, Neutral
or Drive. PCM uses input signal for controlling cruise control system,
transmission torque converter clutch operation and transmission
overdrive solenoid. When park/neutral switch is in Park or Neutral,
switch also provides a ground circuit for the engine starting system.
Park/neutral switch is located on the driver's side of transmission,
near shift linkage.
Transmission Governor Pressure Sensor (A/T Models)
Transmission governor pressure sensor delivers input signal
to Powertrain Control Module (PCM) to indicate transmission governor
pressure. PCM uses input signal for controlling governor pressure by
use of governor pressure solenoid on transmission valve body.
Transmission Temperature Sensor (A/T Models)
Transmission temperature sensor monitors transmission fluid
temperature and delivers input signal to Powertrain Control Module
(PCM). PCM uses input signal for controlling transmission torque
converter clutch operation, transmission overdrive shifts and governor
pressure. Transmission temperature sensor is located on transmission
valve body, incorporated into governor pressure sensor.
PCM prevents torque converter clutch engagement and
transmission overdrive operation when transmission fluid temperature
is less than 50
F (10 C). If transmission fluid temperature is more
than 260 F (126 C), PCM forces a 4-3 downshift and engages torque
converter clutch until transmission fluid cools down. Once
transmission fluid cools to less than 230
F (110 C), PCM allows a 3-4
shift again.
Vehicle Speed & Distance
Vehicle speed sensor is no longer used. The vehicle speed and
distance traveled are determined by rear wheel speed sensor. Rear
wheel speed sensor is mounted on top of rear axle housing, above the
ring gear. Rear wheel speed sensor delivers an input signal to
Controller Anti-Lock Brake (CAB) to indicate vehicle speed and
distance traveled. The CAB then delivers input signal to Powertrain
Control Module (PCM) to indicate vehicle speed and distance traveled.
PCM uses input signal for controlling control cruise control system
and fuel system. The CAB is mounted on top of the hydraulic control
unit. Hydraulic control unit contains the pump assembly that
converter lock-up. ECM uses various input signals such as transmission
temperature, output shaft speed, central module timer, engine speed,
APPS and brake switch position to determine operation of transmission
torque converter clutch solenoid. Transmission torque converter clutch
solenoid is located on transmission valve body.
FUEL SYSTEM
FUEL DELIVERY
Fuel Injection Pump
A camshaft-driven Bosch VP44 in-line fuel injection pump is
used to supply high pressure fuel to each fuel injector in precise
metered amounts at the correct time. See Fig. 2. The pump is timed to
camshaft gear. Pump output is controlled by integral Fuel Pump Control
Module (FPCM). Because of electronic control, idle speeds and pump
timing are not adjustable. See ON-VEHICLE ADJUSTMENTS - TRUCKS -
DIESEL article. FPCM can operate engine if crankshaft position sensor
signal does not exist. Fuel injection occurs near completion of
compression stroke for each cylinder.
Fuel injection pump contains an overflow valve which allows
excess fuel to return to the fuel tank. Overflow valve is located on
side of fuel injection pump and is used to attach the fuel return line
to the fuel injection pump.
Fuel Transfer Pump
Fuel transfer pump is located on driver's side of cylinder
block, above starter. See Fig. 2. A 12 volt, 12-amp electric vane-type
pump supplies low fuel pressure from fuel tank, through fuel
heater/fuel filter/water separator to fuel injection pump. Fuel
transfer pump contains internal check valves to prevent fuel from
bleeding back into fuel tank during engine shutdown. Pump will self
prime with ignition on for 2 seconds. Pump has 2 modes, 100 percent
duty cycle (10 psi) when engine is running and 25 percent duty cycle
(7 psi) when engine is cranking.
Fuel Filter/Water Separator
Fuel filter/water separator, located on left side of engine,
protects injection pump by removing water and contaminants from fuel.
See Fig. 2 . Assembly also includes fuel heater and Water-In-Fuel (WIF)
sensor.
In-Tank Fuel Filter
A separate in-tank fuel filter is attached to bottom of fuel
tank module. In-tank fuel filter does not require service under normal
conditions.
FUEL CONTROL
Fuel Injector
Fuel injector delivers atomized fuel into the cylinder.
During fuel injection, fuel pressure from fuel injection pump
increases to fuel injector opening pressure or pop pressure of 4500
psi (316 kg/cm
). This is the pressure required to lift fuel injector
needle valve from its seat, allowing fuel to be injected into the
cylinder. Once fuel pressure decreases to less then the opening
pressure, a spring forces needle valve closed and stops fuel injection
into the cylinders. Each fuel injector is connected to injection pump
by a high pressure (as much as 17,405 psi) line.
Fuel Injection Timing
Pump output is controlled by integral Fuel Pump Control
using DLC and a scan tool. The DLC also provides a means to
communicate with various vehicle control modules, check system
operating conditions and to operate various system components.
MALFUNCTION INDICATOR LIGHT (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
MISCELLANEOUS CONTROLS
TRANSMISSION
Transmission Overdrive Solenoid (A/T Models)
Engine Control Module (ECM) operates transmission overdrive
solenoid for controlling transmission overdrive shifts. Transmission
overdrive solenoid is located on transmission valve body.
Transmission Torque Converter Clutch Solenoid (A/T Models)
Engine Control Module (ECM) operates transmission torque
converter clutch solenoid for torque converter lock-up. ECM uses
various input signals such as transmission temperature, output shaft
speed, central module timer, engine speed, APPS and brake switch
position to determine operation of transmission torque converter
clutch solenoid. Torque converter clutch solenoid is located on
transmission valve body.
PCM controls operation of electric cooling fan. PCM operates fan
through radiator fan relay by grounding or ungrounding relay control
circuit. PCM regulates engine idle speed through IAC motor when fan is
on.
SHIFT INDICATOR LIGHT
PCM provides ground for shift indicator light on models
equipped with manual transmission. Based on engine speed, throttle
position, and vehicle speed, PCM turns shift indicator light on to
advise driver to shift to a higher gear for optimum fuel economy.
SPEED CONTROL SERVO
System is electrically actuated and vacuum operated. Controls
are located on steering wheel. Controls consist of 3 buttons: OFF/ON,
RESUME/ACCEL and SET/DECEL. Speed control servo is controlled by PCM.
System will operate at 35-85 MPH.
TACHOMETER
PCM provides signal to drive tachometer.
TORQUE CONVERTER CLUTCH (TCC) SOLENOID
PCM controls torque converter lock-up through TCC solenoid.
PCM controls lock-up according to various operating conditions.
TRANSMISSION GOVERNOR SOLENOID
PCM controls solenoid to regulate line pressure for shift
control.
TRANSMISSION OVERDRIVE/OVERRIDE (OD/OR) SWITCH INDICATOR
LIGHT
PCM controls indicator light on OD/OR switch on models
equipped with overdrive automatic transmission.
TRANSMISSION OVERDRIVE (OD) SOLENOID
On models equipped with OD transmission, PCM controls 3-4 OD
upshift and downshift through OD solenoid. PCM determines optimum OD
shift scheduling for all operating conditions.
TR AN SM IS SIO N R EM OVA L & IN STA LLA TIO N
1999 D odge P ic ku p R 1500
1998-99 TRANSMISSION SERVICING
CHRY - Trans Removal & Installation - Trucks & RWD Vans
Dakota, Ram Pickup, Ram Van/Wagon
WARNING: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
MANUAL TRANSMISSION
NOTE: For manual transmission replacement procedures, see
appropriate article in CLUTCHES.
AUTOMATIC TRANSMISSION
DAKOTA & DURANGO
Removal
1) Disconnect negative battery cable. Raise and support
vehicle. Disconnect and remove necessary skid plates and exhaust
components for transmission removal. Remove engine-to-transmission
struts (if equipped). These struts are located between front of
transmission and engine.
2) Ensure area around transmission oil cooler lines fitting
are clean. Disengage retainer on quick-disconnect cooler line fitting.
Pull cooler line from transmission oil cooler.
CAUTION: Crankshaft position sensor must be removed from transmission
housing before removing transmission to prevent damage to
crankshaft position sensor.
3) Remove starter. Disconnect electrical connector for
crankshaft position sensor. On 2.5L, crankshaft position sensor is
mounted on driver's side of transmission housing. See Fig. 1. On 3.9L,
5.2L and 5.9L, crankshaft position sensor is mounted on passenger's
side of transmission housing. See Fig. 2.
4) Remove crankshaft position sensor bolts or nuts. Remove
crankshaft position sensor from transmission housing. Remove dipstick,
dipstick tube and "O" ring from transmission.
5) Remove torque converter cover. Place reference mark on
flexplate and torque converter for installation reference. Rotate
crankshaft clockwise and remove torque converter bolts.
6) Place reference mark on drive shaft flanges for
installation reference. Remove drive shaft from transmission. On 4WD
models, disconnect drive shaft from transfer case. Disconnect shift
rod for transfer case from transfer case shift lever.
7) On all models, disconnect necessary control cables, wiring
harnesses, and shift linkage or cable from transmission. Support rear
of engine with jack stand. Using transmission jack, slightly raise
transmission to release pressure from rear mount and rear crossmember.
8) Remove bolts securing rear support and rear mount to
transmission and rear crossmember. Raise transmission slightly. Slide
exhaust hanger arm from bracket on rear support. Remove rear support
and rear mount.
9) Remove rear crossmember located below the transmission. On
4WD models, disconnect electrical connectors from transfer case. On
all models, remove transmission-to-cylinder block bolts. Slide
transmission rearward from dowels on cylinder block.
10) Install "C" clamp on edge of transmission housing to hold
torque converter in place. Lower transmission and remove transmission
from vehicle.
Fig. 1: Locating Crankshaft Position Sensor (2.5L)
Courtesy of Chrysler Corp.
Fig. 2: Locating Crankshaft Position Sensor (3.9L, 5.2L & 5.9L
Gasoline)
Courtesy of Chrysler Corp.
Installation
1) To install, reverse removal procedure. Ensure torque
converter is fully seated in transmission by measuring distance from
cylinder block surface on transmission housing to front edge on torque
converter bolt lug on front of torque converter. Distance should be .
50" (12.7 mm) if torque converter is fully seated.
CAUTION: Proper length torque converter bolts must be used. If
replacing any torque converter bolts, ensure proper length
bolt is used.
2) Tighten bolt/nuts to specification. See TORQUE
SPECIFICATIONS. Ensure reference mark on torque converter and
flexplate, and drive shaft flanges are aligned. Adjust shift cable or
linkage, throttle valve cable and transfer case shift linkage if
necessary. See AUTOMATIC TRANSMISSION - TRUCKS & RWD VANS article.
3) Use NEW "O" ring when installing dipstick tube. Before
installing oil cooler lines on transmission, ensure all fittings are
clean. Install oil cooler line into quick-disconnect fitting. Push oil
cooler line inward until a click is heard. Pull on oil cooler line to
ensure oil cooler line is locked in place. Fill transmission with
Mopar ATF Plus Type 7176.
RAM PICKUP
Removal
1) Disconnect negative battery cable. Raise and support
vehicle. Disconnect and remove necessary skid plates and exhaust
components for transmission removal. Remove engine-to-transmission
struts (if equipped). These struts are located between front of
transmission and engine.
2) Ensure area around transmission oil cooler lines fitting
are clean. Disengage retainer on quick-disconnect cooler line fitting.
Pull cooler line from transmission oil cooler. Remove starter.
CAUTION: On 3.9L, 5.2L and 5.9L gasoline models, crankshaft position
sensor must be removed from transmission housing before
removing transmission to prevent damage to crankshaft
position sensor.
3) On 3.9L, 5.2L and 5.9L gasoline models, disconnect
electrical connector for crankshaft position sensor. Crankshaft
position sensor is mounted on passenger's side of transmission
housing. See Fig. 2.
4) Remove crankshaft position sensor bolts. Remove crankshaft
position sensor from transmission housing. Remove dipstick, dipstick
tube and "O" ring from transmission.
5) Remove torque converter cover. Place reference mark on
flexplate and torque converter for installation reference. Rotate
crankshaft clockwise and remove torque converter bolts.
6) Place reference mark on drive shaft flanges for
installation reference. Remove drive shaft from transmission. On 4WD
models, disconnect drive shaft from transfer case. Disconnect shift
rod for transfer case from transfer case shift lever.
7) On all models, disconnect necessary control cables, wiring
harnesses, and shift linkage from transmission. Support rear of engine
with jack stand. Using transmission jack, slightly raise transmission
to release pressure from rear mount and rear crossmember.
8) Remove bolts securing rear support and rear mount to
transmission and rear crossmember. Raise transmission slightly. Slide
exhaust hanger arm from bracket on rear support. Remove rear support