1999 DODGE RAM radiator

diagram in appropriate WIRING DIAGRAMS article. For theory
and operation on each output component, refer to indicated
system.
A/C Clutch Relay
See A/C CLUTCH RELAY under MISCELLANEOUS CONTROLS.
Auto Shutdown (ASD) Relay
See AUTO SHUTDOWN (ASD) RELAY & FUEL PUMP RELAY under
MISCELLANEOUS CONTROLS.
Distributorless Ignition System (DIS)
See DISTRIBUTORLESS IGNITION SYSTEM (DIS) under IGNITION
SYSTEM.
Evaporative Canister Purge Control Solenoid (EVAP-CPCS)
See EVAPORATIVE (EVAP) EMISSIONS SYSTEM under EMISSION
SYSTEMS.
Fuel Injectors
See FUEL CONTROL under FUEL SYSTEM.
Fuel Pump Relay
See AUTO SHUTDOWN (ASD) RELAY & FUEL PUMP RELAY under
MISCELLANEOUS CONTROLS.
Generator
See GENERATOR under MISCELLANEOUS CONTROLS.
Idle Air Control (IAC) Motor
See IDLE SPEED under FUEL SYSTEM.
Ignition Coil
See IGNITION SYSTEM.
In-Tank Fuel Pump
See FUEL DELIVERY under FUEL SYSTEM.
Limp-In Mode
See LIMP-IN MODE under MISCELLANEOUS CONTROLS.
Malfunction Indicator Light (MIL)
See MALFUNCTION INDICATOR LIGHT under SELF-DIAGNOSTIC SYSTEM.
Radiator Fan Relay
See RADIATOR FAN RELAY under MISCELLANEOUS CONTROLS.
Serial Communications Interface (SCI) Transmit
See SERIAL COMMUNICATIONS INTERFACE (SCI) under SELF-
DIAGNOSTIC SYSTEM.
Shift Indicator Light
See SHIFT INDICATOR LIGHT under MISCELLANEOUS CONTROLS.
Speed Control Servo
See SPEED CONTROL SERVO under MISCELLANEOUS CONTROLS.
Tachometer
See TACHOMETER under MISCELLANEOUS CONTROLS.
Torque Converter Clutch (TCC) Solenoid
See TORQUE CONVERTER CLUTCH (TCC) SOLENOID under
MISCELLANEOUS CONTROLS.

PCM.
MISCELLANEOUS CONTROLS
NOTE: Although not strictly considered part of engine performance
system, some controlled devices can adversely affect
driveability if they malfunction.
A/C CLUTCH RELAY
A/C clutch relay is controlled by PCM. When A/C or Defrost
mode is selected and PCM receives A/C request signal from evaporator
switch, PCM will cycle clutch on and off through A/C clutch relay.
When this relay is energized during engine operation, PCM will
determine correct engine idle speed through IAC motor.
When PCM senses low idle speed or wide open throttle through
TP sensor, PCM will de-energize A/C clutch relay, preventing A/C
operation.
AUTO SHUTDOWN (ASD) RELAY & FUEL PUMP RELAY
ASD relay and electric fuel pump relay are energized when
ignition is on. These relays are controlled through PCM by switching a
common ground circuit on and off. Following components are controlled
by ASD and fuel pump relays:
* Electric Fuel Pump
* Fuel Injectors
* Generator Field Winding
* Ignition Coil(s)
* HO2S Heating Element
When ignition switch is turned to RUN position, PCM energizes
ASD relay and electric fuel pump relay which powers these components.
If PCM does not receive a CMP and CKP sensor signal within one second
of engine cranking (start-up), PCM will turn ground circuit off and
de-energize ASD relay.
GENERATOR
Powertrain Control Module (PCM) regulates charging system
voltage.
LIMP-IN MODE
Limp-in mode is the attempt by PCM to compensate for failure
of certain components by substituting information from other sources
so that vehicle can still be operated. If PCM senses incorrect data or
no data at all from MAP sensor, TP sensor, ECT sensor or battery
voltage, system is placed into limp-in mode and Malfunction Indicator
Light (MIL) on instrument panel comes on.
If faulty sensor comes back on line, PCM will resume closed
loop operation. On some vehicles, MIL will remain on until ignition is
shut off and vehicle is restarted. To prevent damage to catalytic
converter, vehicle should NOT be driven for extended periods in limp-
in mode.
RADIATOR FAN RELAY
Electric cooling fan is used only on Dakota. Using
information supplied by A/C signal (if equipped), ECT sensor, and VSS,\

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.

bolster. Remove CTM from bracket on inboard side of instrument panel
steering column opening. Disconnect harness connectors. To install,
reverse removal procedure.
INTERMITTENT WIPER RELAY
Removal & Installation
Intermittent wiper relay is located in Power Distribution
Center (PDC) in engine compartment. Remove cover and remove relay. To
install, reverse removal procedures
WIPER ARMS
Removal & Installation
Open hood. Lift wiper and slide latch to hold wiper off of
windshield. With a rocking motion, remove wiper arm. To install,
ensure wiper motor is in park position. Slide wiper arm on shaft.
Align wiper arms. See WIPER BLADES under ADJUSTMENTS.
WIPER MOTOR
NOTE: Wiper linkage and motor module is replaced as a unit.
Removal & Installation
1) Disconnect negative battery cable. Remove wiper arms. See
WIPER ARMS. Remove weatherstrip along front edge of cowl. Release
plastic anchor screws. Lift cowl grille from vehicle. Remove washer
hose from "Y" fitting. Set grille aside.
2) Remove wiper linkage mounting bolts. Turn linkage over and
disconnect harness connector from wiper motor. Remove wiper linkage
and motor module. To install, reverse removal procedure. Align wiper
arms. See WIPER BLADES under ADJUSTMENTS.
WIPER/WASHER SWITCH
NOTE: Wiper/washer switch is part of multifunction steering column
switch. If wiper/washer switch fails, entire multifunction
switch must be replaced.
Removal & Installation
1) Disconnect negative battery cable. Remove tilt lever (if
equipped). Remove steering column upper and lower covers to access
switch connector. Remove switch connector. Remove multifunction switch
tamperproof screws.
2) Gently pull switch away from column and loosen connector
screw (screw remains in connector). Remove switch. To install, reverse\
removal procedure. Tighten screws and nuts to specification. See
TORQUE SPECIFICATIONS. Ensure switch is functioning properly.
WASHER RESERVOIR
Removal & Installation
Disconnect negative battery cable. Drain cooling system.
Disconnect upper radiator hose from radiator. Disconnect harness
connectors from washer pump and washer fluid level sensor. Remove
washer supply hose from washer pump and drain washer fluid. While
pulling reservoir away from fan shroud, lift reservoir upward to
disengage mounting tabs from fan shroud. Remove washer reservoir. To
install, reverse removal procedure.
WASHER MOTOR
Removal & Installation