1999 DODGE NEON parking sensors

cally cleared from the CAB memory after the identi-
cal fault has not been seen during the next 255 key
cycles of vehicle operation.
CONTROLLER ANTILOCK BRAKE INPUTS
²Four wheel speed sensors.
²Stop lamp switch.
²Ignition switch.
²System relay voltage.
²Ground.
²Diagnostics Communications (CCD)
CONTROLLER ANTILOCK BRAKE OUTPUTS
²ABS warning lamp actuation.
²Diagnostic communication. (CCD)
ABS WARNING LAMP (YELLOW)
The ABS system uses a yellow colored ABS Warn-
ing Lamp. The ABS warning lamp is located on the
lower left side of the instrument pane. The purpose
of the warning lamp is discussed in detail below.
The ABS warning lamp will turn on when the CAB
detects a condition which results in a shutdown of
ABS function. When the ignition key is turned to the
on position, the ABS Warning Lamp is on until the
CAB completes its self tests and turns the lamp off
(approximately 4 seconds after the ignition switch is
turned on). Under most conditions, when the ABS
warning lamp is on, only the ABS function of the
brake system is affected. The standard brake system
and the ability to stop the car will not be affected
when only the ABS warning lamp is on.
The ABS warning lamp is controlled by the CAB.
The CAB turns on the yellow ABS warning lamp by
grounding the circuit.
HYDRAULIC CIRCUITS AND VALVE OPERATION
Through the following operation descriptions the
function of the various hydraulic control valves in the
ABS will be described. The fluid control valves men-
tioned below, control the flow of pressurized brake
fluid to the wheel brakes during the different modes
of ABS braking.
For explanation purposes, all wheel speed sensors
except the right front are sending the same wheel
speed information. The following diagrams show only
the right front wheel in a antilock braking condition.
NORMAL BRAKING HYDRAULIC CIRCUIT AND
SOLENOID VALVE FUNCTION
This condition is the normal operation of the vehi-
cles base brake hydraulic system. The hydraulic sys-
tem circuit diagram (Fig. 11) shows a situation where
no wheel spin or slip is occurring relative to the
speed of the vehicle. The driver is applying the brake
pedal to build pressure in the brake hydraulic system
to apply the brakes and stop the vehicle.
TEVES MARK 20 ABS CIRCUIT AND
SOLENOID VALVE FUNCTION
This hydraulic circuit diagram (Fig. 12) shows the
vehicle in the ABS braking mode. This hydraulic cir-
cuit (Fig. 12) shows a situation where one wheel is
slipping because the driver is attempting to stop the
vehicle at a faster rate than the surface the vehicle's
tires are on will allow. The normally open and nor-
mally closed valves modulate the brake hydraulic
pressure as required. The pump/motor is switched on
so that the brake fluid from the low pressure accu-
mulators is returned to the master cylinder circuits.
The brake fluid will then be routed to either the mas-
ter cylinder or the wheel brake depending on the
position of the normally open valve.
TEVES MARK 20 SECONDARY ABS CIRCUIT
AND SOLENOID VALVE FUNCTION
This hydraulic circuit diagram (Fig. 13) shows the
vehicle in the ABS braking mode. This hydraulic cir-
cuit (Fig. 13) shows a situation where one wheel is
slipping because the driver is attempting to stop the
vehicle at a faster rate than the surface the vehicle's
tires are on will allow. The normally open and nor-
mally closed valves modulate the brake hydraulic
pressure as required. The pump/motor is switched on
so that the brake fluid from the low pressure accu-
mulators is returned to the master cylinder circuits.
The brake fluid will then be routed to either the mas-
ter cylinder or the wheel brake depending on the
position of the normally open valve. A volume of 1.2
cc's of brake fluid is taken in by the lip seal saver
(Fig. 13) to protect the lip seals on the piston of the
master cylinder.
DIAGNOSIS AND TESTING
ABS GENERAL DIAGNOSTICS INFORMATION
This section contains the information necessary to
diagnose the ITT Teves Mark 20 ABS Brake System.
Specifically, this section should be used to help diag-
nose conditions which result in any of the following:
(1) ABS Warning Lamp turned on.
(2) Brakes Lock-up on hard application
Diagnosis of base brake conditions which are obvi-
ously mechanical in nature should be directed to
Group 5 Brakes in this service manual. This includes
brake noise, brake pulsation, lack of power assist,
parking brake, Red BRAKE Warning Lamp lighting,
or vehicle vibration during normal braking.
Many conditions that generate customer com-
plaints may be normal operating conditions, but are
judged to be a problem due to not being familiar with
the ABS system. These conditions can be recognized
without performing extensive diagnostic work, given
adequate understanding of the operating principles
PLBRAKES 5 - 75
DESCRIPTION AND OPERATION (Continued)

train Control Module (PCM) with an input signal
(voltage). The signal represents throttle blade posi-
tion. As the position of the throttle blade changes,
the resistance of the TPS changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
powertrain control module) represents throttle blade
position. The TPS output voltage to the PCM varies
from approximately 0.38 volts to 1.2 volts at mini-
mum throttle opening (idle) to a maximum of 3.1
volts to 4.4 volts at wide open throttle.
Along with inputs from other sensors, the PCM
uses the TPS input to determine current engine oper-
ating conditions. The PCM also adjusts fuel injector
pulse width and ignition timing based on these
inputs.
IGNITION SWITCH
In the RUN position, the ignition switch connects
power from the Power Distribution Center (PDC) to a
30 amp fuse in the fuse block, back to a bus bar in
the PDC. The bus bar feeds circuits for the Power-
train Control Module (PCM), duty cycle purge sole-
noid, EGR solenoid, and ABS system. The bus bar in
the PDC feeds the coil side of the radiator fan relay,
A/C compressor clutch relay, and the fuel pump relay.
It also feeds the Airbag Control Module (ACM)
LOCK KEY CYLINDER
The lock cylinder is inserted in the end of the
housing opposite the ignition switch. The ignition key
rotates the cylinder to 5 different detents (Fig. 16):
²Accessory
²Off (lock)
²Unlock
²On/Run
²Start
IGNITION INTERLOCK
All vehicles equipped with automatic transaxles
have an interlock system. The system prevents shift-
ing the vehicle out of Park unless the ignition lock
cylinder is in the Off, Run or Start position. In addi-
tion, the operator cannot rotate the key to the lock
position unless the shifter is in the park position. On
vehicles equipped with floor shift refer to Group 21 -
Transaxle for Automatic Transmission Shifter/Igni-
tion Interlock.
DIAGNOSIS AND TESTING
TESTING FOR SPARK AT COILÐ2.0/2.4L
WARNING: THE DIRECT IGNITION SYSTEMS GEN-
ERATES APPROXIMATELY 40,000 VOLTS. PER-
SONAL INJURY COULD RESULT FROM CONTACT
WITH THIS SYSTEM.
The coil pack contains independent coils. Each coil
must be checked individually.
CAUTION: Spark plug wire damage may occur if
the spark plug is moved more than 1/4 inch away
from the engine ground.
CAUTION: Do not leave any one spark plug cable
disconnected any longer than 30 seconds or possi-
ble heat damage to catalytic converter will occur.
CAUTION: Test must be performed at idle and in
park only with the parking brake on.
NOTE: New isolated engine valve cover may not
provide adequate ground. Use engine block as
engine ground.
Fig. 15 MAP/IAT sensorÐDOHCFig. 16 Ignition Lock Cylinder Detents
PLIGNITION SYSTEM 8D - 7
DESCRIPTION AND OPERATION (Continued)

POWER STEERING PRESSURE SWITCHÐPCM
INPUT
A pressure sensing switch is located on the power
steering gear. The switch (Fig. 16) provides an input
to the PCM during periods of high pump load and
low engine RPM; such as during parking maneuvers.
When power steering pump pressure exceeds 2758
kPa (400 psi), the switch is open. The PCM increases
idle air flow through the IAC motor to prevent
engine stalling. When pump pressure is low, the
switch is closed.
SENSOR RETURNÐPCM INPUT
The sensor return circuit provides a low electrical
noise ground reference for all of the systems sensors.
The sensor return circuit connects to internal ground
circuits within the powertrain control module.
SPEED CONTROL SERVOSÐPCM OUTPUT
The PCM controls the speed control vacuum servo.
The PCM supplies power, through the brake switch,
to the servo. Based on the speed control switch
inputs to the PCM and the speed control strategy,
the PCM provides ground to the servo vacuum or
vent circuit as required. When the PCM supplies a
ground to the servo vacuum circuit, the speed control
system opens the throttle plate to obtain or maintain
the selected road speed. When the PCM supplies a
ground to the servo vent circuit, the speed control
system releases the throttle plate. Refer to Group 8H
for speed control information.
SCI RECEIVEÐPCM INPUT
SCI Receive is the serial data communication
receive circuit for the DRB scan tool. The Powertrain
Control Module (PCM) receives data from the DRB
through the SCI Receive circuit.
PARK/NEUTRAL POSITION SWITCHÐPCM INPUT
The park/neutral position switch is located on the
automatic transaxle housing (Fig. 17). Manual tran-
saxles do not use park/neutral switches. The switch
provides an input to the PCM to indicate whether
the automatic transaxle is in Park/Neutral, or a drive
gear selection. This input is used to determine idle
speed (varying with gear selection) and ignition tim-
ing advance. The park/neutral input is also used to
cancel vehicle speed control. The park/neutral switch
is sometimes referred to as the neutral safety switch.
THROTTLE POSITION SENSORÐPCM INPUT
The throttle position sensor mounts to the side of
the throttle body (Fig. 18) and (Fig. 19).
The Throttle Position Sensor (TPS) connects to the
throttle blade shaft. The TPS is a variable resistor
that provides the PCM with an input signal (voltage).
The signal represents throttle blade position. As the
position of the throttle blade changes, the resistance
of the TPS changes.
The PCM supplies approximately 5 volts DC to the
TPS. The TPS output voltage (input signal to the
powertrain control module) represents throttle blade
position. The TPS output voltage to the PCM varies
from approximately 0.35 to 1.03 volts at minimum
throttle opening (idle) to a maximum of 3.1 to 4.0
volts at wide open throttle.
Along with inputs from other sensors, the PCM
uses the TPS input to determine current engine oper-
ating conditions. The PCM also adjusts fuel injector
pulse width and ignition timing based on these
inputs.
VEHICLE SPEED SENSORÐPCM INPUT
The vehicle speed sensor is located in the transmis-
sion extension housing (Fig. 20) and (Fig. 21). The
sensor input is used by the PCM to determine vehicle
speed and distance traveled.
Fig. 16 Power Steering Pressure SwitchFig. 17 Park/Neutral Switch
14 - 30 FUEL SYSTEMPL
DESCRIPTION AND OPERATION (Continued)