differential DODGE RAM 2002 Service Owners Manual

PINION GEAR/RING GEAR/
TONE RING
REMOVAL
NOTE: The ring and pinion gears are service as a
matched set. Never replace the ring gear without
replacing the matched pinion gear.
(1) Remove differential from the housing.
(2) Place differential case in a vise with soft metal
jaw protectors. (Fig. 43)
(3) Remove the ring gear bolts.
(4) Drive ring gear from differential case with a
soft hammer (Fig. 43).
(5) Remove the exciter ring from the differential
case by tapping it off with a brass drift.
(6) Hold the pinion yoke with Holder 6719A and
remove pinion yoke nut and washer.
(7) Remove pinion yoke with Remover C-452 and
Wrench C-3281 (Fig. 44).
(8) Remove pinion gear from housing (Fig. 45).
(9) Remove pinion seal with a slide hammer or pry
bar.
(10) Remove oil slinger, if equipped, and the front
pinion bearing.
Fig. 43 RING GEAR
1 - DIFFERENTIAL CASE
2 - RING GEAR
3 - HAMMER
Fig. 44 PINION YOKE REMOVER
1 - WRENCH
2 - YOKE
3 - REMOVER
Fig. 45 PINION GEAR REMOVAL
1 - RAWHIDE HAMMER
BR/BEREAR AXLE - 286RBI 3 - 131

(10) Check bearing rotating torque with an inch
pound torque wrench (Fig. 54). Pinion rotating torque
should be:
²Original Bearings: 1 to 3 N´m (10 to 20 in. lbs.).
²New Bearings: 2.8 to 5.1 N´m (25 to 45 in. lbs.).
(11) If rotating torque is less than the desired
rotating torque, remove the pinion yoke and decrease
the thickness of the solid shim pack if greater
increase shim pack. Changing the shim pack thick-
ness by 0.025 mm (0.001 in.) will change the rotating
torque approximately 0.9 N´m (8 in. lbs.).
(12) Invert the differential case.
(13) Position exciter ring on differential case and
tap onto the case with a brass drift slowly and
evenly.
(14) Invert differential case and start two ring
gear bolts. This will provide case-to-ring gear bolt
hole alignment.
(15) Invert the differential case in the vise.
(16) Installnewring gear bolts and alternately
tighten to 298 N´m (220 ft. lbs.) (Fig. 55).
CAUTION: Never reuse the ring gear bolts. The
bolts can fracture causing extensive damage.
(17) Install differential in housing and verify gear
mesh and contact pattern.
Fig. 53 PINION YOKE
1 - INSTALLER
2 - HOLDERFig. 54 Pinion Rotating Torque
1 -TORQUE WRENCH
2 - PINION YOKE
Fig. 55 RING GEAR BOLT
1 - TORQUE WRENCH
2 - RING GEAR BOLT
3 - RING GEAR
4 - CASE
3 - 134 REAR AXLE - 286RBIBR/BE
PINION GEAR/RING GEAR/TONE RING (Continued)

STANDARD PROCEDURE - PRESSURE
BLEEDING
Use Mopar brake fluid, or an equivalent quality
fluid meeting SAE J1703-F and DOT 3 standards
only. Use fresh, clean fluid from a sealed container at
all times.
If pressure bleeding equipment will be used, the
front brake metering valve will have to be held open
to bleed the front brakes. The valve stem is located
in the forward end or top of the combination valve.
The stem must either be pressed inward, or held out-
ward slightly. A spring clip tool or helper is needed to
hold the valve stem in position.
Follow the manufacturers instructions carefully
when using pressure equipment. Do not exceed the
tank manufacturers pressure recommendations. Gen-
erally, a tank pressure of 15-20 psi is sufficient for
bleeding.
Fill the bleeder tank with recommended fluid and
purge air from the tank lines before bleeding.
Do not pressure bleed without a proper master cyl-
inder adapter. The wrong adapter can lead to leak-
age, or drawing air back into the system. Use
adapter provided with the equipment or Adapter
6921.
BRAKE LINES
STANDARD PROCEDURE
STANDARD PROCEDURE - DOUBLE INVERTED
FLARING
A preformed metal brake tube is recommended and
preferred for all repairs. However, double-wall steel
tube can be used for emergency repair when factory
replacement parts are not readily available.
(1) Cut off damaged tube with Tubing Cutter.
(2) Ream cut edges of tubing to ensure proper
flare.
(3) Install replacement tube nut on the tube.
(4) Insert tube in flaring tool.
(5) Place gauge form over the end of the tube.
(6) Push tubing through flaring tool jaws until
tube contacts recessed notch in gauge that matches
tube diameter.
(7) Tighten the tool bar on the tube
(8) Insert plug on gauge in the tube. Then swing
compression disc over gauge and center tapered flar-
ing screw in recess of compression disc (Fig. 2).
(9) Tighten tool handle until plug gauge is
squarely seated on jaws of flaring tool. This will start
the inverted flare.
(10) Remove the plug gauge and complete the
inverted flare.
STANDARD PROCEDURE - ISO FLARING
A preformed metal brake tube is recommended and
preferred for all repairs. However, double-wall steel
tube can be used for emergency repair when factory
replacement parts are not readily available.
To make a ISO flare use an ISO flaring tool kit.
(1) Cut off damaged tube with Tubing Cutter.
(2) Remove any burrs from the inside of the tube.
(3) Install tube nut on the tube.
(4) Position the tube in the flaring tool flush with
the top of the tool bar (Fig. 3). Then tighten the tool
bar on the tube.
(5) Install the correct size adaptor on the flaring
tool yoke screw.
(6) Lubricate the adaptor.
(7) Align the adaptor and yoke screw over the tube
(Fig. 3).
(8) Turn the yoke screw in until the adaptor is
squarely seated on the tool bar.
COMBINATION VALVE
DESCRIPTION
The combination valve/rear brake proportioning
valve are not repairable and must be replaced as an
assembly.
The pressure differential switch is connected to the
brake warning lamp.
Fig. 2 Inverted Flare Tools
5 - 8 BRAKES - BASEBR/BE
HYDRAULIC/MECHANICAL (Continued)

OPERATION
PRESSURE DIFFERENTIAL SWITCH
The switch is triggered by movement of the switch
valve. The purpose of the switch is to monitor fluid
pressure in the separate front/rear brake hydraulic
circuits.
A decrease or loss of fluid pressure in either
hydraulic circuit will cause the switch valve to shut-
tle forward or rearward in response to the pressure
differential. Movement of the switch valve will push
the switch plunger upward. This closes the switch
internal contacts completing the electrical circuit to
the warning lamp. The switch valve may remain in
an actuated position until repair restores system
pressures to normal levels.
DIAGNOSIS AND TESTING - COMBINATION
VALVE
Pressure Differential Switch
(1) Have helper sit in drivers seat to apply brake
pedal and observe red brake warning light.
(2) Raise vehicle on hoist.(3) Connect bleed hose to a rear wheel cylinder
and immerse hose end in container partially filled
with brake fluid.
(4) Have helper press and hold brake pedal to floor
and observe warning light.
(a) If warning light illuminates, switch is operat-
ing correctly.
(b) If light fails to illuminate, check circuit fuse,
bulb, and wiring. The parking brake switch can be
used to aid in identifying whether or not the brake
light bulb and fuse is functional. Repair or replace
parts as necessary and test differential pressure
switch operation again.
(5) If warning light still does not illuminate,
switch is faulty. Replace combination valve assembly,
bleed brake system and verify proper switch and
valve operation.
REMOVAL
(1) Remove pressure differential switch wire con-
nector (Fig. 4) from the valve.
(2) Remove the brake lines from the valve.
(3) Remove the valve mounting bolt and remove
the valve from the bracket.
INSTALLATION
(1) Position the valve on the bracket and install
the mounting bolt. Tighten the mounting bolt to 23
N´m (210 in. lbs.).
(2) Install the brake lines into the valve and
tighten to 19-23 N´m (170-200 in. lbs.).
Fig. 3 ISO Flaring
1 - ADAPTER
2 - LUBRICATE HERE
3 - PILOT
4 - FLUSH WITH BAR
5 - TUBING
6 - BAR ASSEMBLY
Fig. 4 Pressure
1 - COMBINATION VALVE
2 - BRAKE LINES
3 - MOUNTING BOLT
4 - PRESSURE DIFFERENTIAL SWITCH
BR/BEBRAKES - BASE 5 - 9
COMBINATION VALVE (Continued)

(3) Connect the pressure differential switch wire
connector.
(4) Bleed base brake system, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL - STAN-
DARD PROCEDURE).
DISC BRAKE CALIPERS
DESCRIPTION
The caliper is a one-piece casting. The piston bores
are located in the inboard side. A square-cut piston
seal is located in a machined groove in the cylinder
bore.
The caliper pistons dust boot prevents dirt, water
and road splash from entering the piston bore. The
boot is seated in a groove machined at the outer end
of the caliper piston. The boot retaining flange is
seated in a counterbore machined in the outer end of
the caliper piston bore.
Ventilated disc brake rotors are used for all appli-
cations. The rotors are serviceable and can be
machined to restore surface finish when necessary.
OPERATION
When the brakes are applied fluid pressure is
exerted against the caliper piston. The fluid pressure
is exerted equally and in all directions. This means
pressure exerted against the caliper piston and
within the caliper bore will be equal (Fig. 5).
Fluid pressure applied to the piston is transmitted
directly to the inboard brake shoe. This forces the
shoe lining against the inner surface of the disc
brake rotor. At the same time, fluid pressure within
the piston bore forces the caliper to slide inward on
the mounting bolts. This action brings the outboard
brake shoe lining into contact with the outer surface
of the disc brake rotor.
In summary, fluid pressure acting simultaneously
on both piston and caliper, produces a strong clamp-
ing action. When sufficient force is applied, friction
will attempt to stop the rotors from turning and
bring the vehicle to a stop.
Application and release of the brake pedal gener-
ates only a very slight movement of the caliper and
piston. Upon release of the pedal, the caliper and pis-
ton return to a rest position. The brake shoes do not
retract an appreciable distance from the rotor. In
fact, clearance is usually at, or close to zero. The rea-
sons for this are to keep road debris from getting
between the rotor and lining and in wiping the rotor
surface clear each revolution.
The caliper piston seal controls the amount of pis-
ton extension needed to compensate for normal lining
wear.During brake application, the seal is deflected out-
ward by fluid pressure and piston movement (Fig. 6).
When the brakes (and fluid pressure) are released,
the seal relaxes and retracts the piston.
The amount of piston retraction is determined by
the amount of seal deflection. Generally the amount
is just enough to maintain contact between the pis-
ton and inboard brake shoe.
REMOVAL
REMOVAL - REAR
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Compress the disc brake caliper using tool
#C4212F.
(4) Remove the caliper pin bolts.
(5) Remove the banjo bolt and discard the copper
washer.
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose with result. Provide a suitable support to hang
the caliper securely.
(6) Remove the rear disc brake caliper (Fig. 7).
Fig. 5 Brake Caliper Operation
1 - CALIPER
2 - PISTON
3 - PISTON BORE
4 - SEAL
5 - INBOARD SHOE
6 - OUTBOARD SHOE
5 - 10 BRAKES - BASEBR/BE
COMBINATION VALVE (Continued)

ROTOR MINIMUM THICKNESS
Measure rotor thickness at the center of the brake
shoe contact surface. Replace the rotor if below min-
imum thickness, or if machining would reduce thick-
ness below the allowable minimum.
Rotor minimum thickness is usually specified on
the rotor hub. The specification is either stamped or
cast into the hub surface.
ROTOR RUNOUT
Check rotor lateral runout with dial indicator
C-3339 (Fig. 31) . Excessive lateral runout will cause
brake pedal pulsation and rapid, uneven wear of the
brake shoes. Position the dial indicator plunger
approximately 25.4 mm (1 in.) inward from the rotor
edge.
NOTE: Be sure wheel bearing has zero end play
before checking rotor runout.
Maximum allowable rotor runout is 0.127 mm
(0.005 in.).
ROTOR THICKNESS VARIATION
Variations in rotor thickness will cause pedal pul-
sation, noise and shudder.
Measure rotor thickness at 6 to 12 points around
the rotor face (Fig. 32) .
Position the micrometer approximately 25.4 mm (1
in.) from the rotor outer circumference for each mea-
surement.
Thickness should notvaryby more than 0.025 mm
(0.001 in.) from point-to-point on the rotor. Machine
or replace the rotor if necessary.
REMOVAL
REMOVAL - REAR
(1) Raise and support the vehicle
(2) Remove the tire and wheel assembly.
(3) Remove the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - REMOVAL).
(4) Remove the caliper adapter bolts.
(5) Remove the rear axle shaft from the housing
on dual rear wheels, (Refer to 3 - DIFFERENTIAL &
DRIVELINE/REAR AXLE - 286RBI/AXLE SHAFTS -
REMOVAL).
(6) Remove the hub and rotor assembly (C3500
only) (Fig. 33).
Fig. 31 Checking Rotor Runout And Thickness
Variation
1 - DIAL INDICATOR
Fig. 32 Measuring Rotor Thickness
1 - MICROMETER
2 - ROTOR
Fig. 33 ROTOR / HUB REMOVAL
BR/BEBRAKES - BASE 5 - 21
ROTORS (Continued)

REMOVAL - FRONT ± 2500
(1) Raise and support the vehicle.
(2) Remove the wheel and tire assembly.
(3) Remove the caliper from the steering knuckle,
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - REMOVAL) and remove
caliper adapter assembly (Fig. 34).
NOTE: Do not allow brake hose to support caliper
adapter assembly.
(4) Remove the rotor from the hub/bearing wheel
studs.
REMOVAL - FRONT - 3500
(1) Raise and support the vehicle.
(2) Remove the wheel and tire assembly.
(3) Remove the hub extension mounting nuts and
remove the extension from the rotor if equipped.
(4) Remove the brake caliper adapter assembly.
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - REMOVAL).
(5) Remove the rotor assembly.
INSTALLATION
INSTALLATION - REAR
(1) Install the hub to the rotor. Tighten the bolts to
128 N´m (95 ft. lbs.) (Fig. 35).
(2) Install the hub and rotor assembly.
(3) Install the rear axle shaft to the housing with
dual wheels, (Refer to 3 - DIFFERENTIAL & DRIV-
ELINE/REAR AXLE - 286RBI/AXLE SHAFTS -
INSTALLATION).
(4) Install the caliper adapter bolts.
(5) Install the disc brake caliper, (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - INSTALLATION). (Fig. 36).
(6) Install the tire and wheel assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(7) Lower the vehicle.
Fig. 34 Caliper Adapter Assembly
1 - KNUCKLE
2 - CALIPER
3 - ROTOR
Fig. 35 ROTOR TO HUB
1 - Hub Bolts
2 - Socket
Fig. 36 ROTOR INSTALLED
5 - 22 BRAKES - BASEBR/BE
ROTORS (Continued)

FRONT WHEEL SPEED
SENSOR
DESCRIPTION
The ABS brake system uses 3 wheel speed sensors.
A sensor is mounted to each front steering knuckles.
The third sensor is mounted on top of the rear axle
differential housing.
OPERATION
The Wheel Speed Sensor consists of a magnet sur-
rounded by windings from a single strand of wire.
The sensor sends a small AC signal to the CAB. This
signal is generated by magnetic induction. The mag-
netic induction is created when a toothed sensor ring
(exciter ring or tone wheel) passes the stationary
magnetic WSS.
When the ring gear is rotated, the exciter ring
passes the tip of the WSS. As the exciter ring tooth
approaches the tip of the WSS, the magnetic lines of
force expand, causing the magnetic field to cut across
the sensor's windings. This, in turn causes current to
flow through the WSS circuit (Fig. 2) in one direc-
tion. When the exciter ring tooth moves away from
the sensor tip, the magnetic lines of force collapse
cutting the winding in the opposite direction. This
causes the current to flow in the opposite direction.
Every time a tooth of the exciter ring passes the tip
of the WSS, an AC signal is generated. Each AC sig-
nal (positive to negative signal or sinewave) is inter-
preted by the CAB. It then compares the frequency of
the sinewave to a time value to calculate vehicle
speed. The CAB continues to monitor the frequency
to determine a deceleration rate that would indicate
a possible wheel-locking tendency.
The signal strength of any magnetic induction sen-
sor is directly affected by:
²Magnetic field strength; the stronger the mag-
netic field, the stronger the signal
²Number of windings in the sensor; more wind-
ings provide a stronger signal
²Exciter ring speed; the faster the exciter ring/
tone wheel rotates, the stronger the signal will be
²Distance between the exciter ring teeth and
WSS; the closer the WSS is to the exciter ring/tone
wheel, the stronger the signal will be
The rear WSS is not adjustable. A clearance speci-
fication has been established for manufacturing toler-
ances. If the clearance is not within these
specifications, then either the WSS or other compo-
nents may be damaged. The clearance between the
WSS and the exciter ring is 0.005 ± 0.050 in.
The assembly plant performs a ªRolls Testº on
every vehicle that leaves the assembly plant. One of
the test performed is a test of the WSS. To properlytest the sensor, the assembly plant connects test
equipment to the Data Link Connector (DLC). This
connector is located to the right of the steering col-
umn and attached to the lower portion of the instru-
ment panel (Fig. 3). The rolls test terminal is spliced
to the WSS circuit. The vehicle is then driven on a
set of rollers and the WSS output is monitored for
proper operation.
Fig. 2 Operation of the Wheel Speed Sensor
1 - MAGNETIC CORE
2 - CAB
3 - AIR GAP
4 - EXCITER RING
5 - COIL
Fig. 3 Data Link Connector - Typical
1 - 16±WAY DATA LINK CONNECTOR
5 - 38 BRAKES - ABSBR/BE

NOTE: Check the sensor wire routing. Be sure the
wire is clear of all chassis components and is not
twisted or kinked at any spot.
(6) Install the tire and wheel assembly.
(7) Remove the support and lower the vehicle.
(8) Reconnect the ABS wheel speed sensor wire
electrical connector inside the engine compartment.
(9) Apply the brakes several times to seat the
brake shoes and caliper piston. Do not move the vehi-
cle until a firm brake pedal is obtained.
(10) Verify the wheel speed sensor operation with
a scan tool.
REAR WHEEL SPEED SENSOR
DIAGNOSIS AND TESTING - REAR WHEEL
SPEED SENSOR
Diagnosis of base brake conditions which are
mechanical in nature should be performed first. This
includes brake noise, lack of power assist, parking
brake, or vehicle vibration during normal braking.
The Antilock brake system performs several self-
tests every time the ignition switch is turned on and
the vehicle is driven. The CAB monitors the system
inputs and outputs circuits to verify the system is
operating properly. If the CAB senses a malfunction
in the system it will set a DTC into memory and trig-
ger the warning lamp.
NOTE: The MDS or DRB III scan tool is used to
diagnose the Antilock Brake system. For test proce-
dures refer to the Chassis Diagnostic Manual.
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove brake line mounting nut and remove
the brake line from the sensor stud.
(3) Remove mounting stud from the sensor and
shield (Fig. 6) .
(4) Remove sensor and shield from differential
housing.
(5) Disconnect sensor wire harness and remove
sensor.
INSTALLATION
(1) Connect harness to sensor.Be sure seal is
securely in place between sensor and wiring
connector.
(2) Install O-ring on sensor (if removed).
(3) Insert sensor in differential housing.
(4) Install sensor shield.
(5) Install the sensor mounting stud and tighten to
24 N´m (18 ft. lbs.).(6) Install the brake line on the sensor stud and
install the nut.
(7) Lower vehicle.
HCU (HYDRAULIC CONTROL
UNIT)
DESCRIPTION
The hydraulic control unit (HCU) consists of a
valve body, pump, two accumulators and a motor.
The assembly is mounted on the driverside inner
fender under the hood.
OPERATION
The pump, motor, and accumulators are combined
into an assembly attached to the valve body. The
accumulators store the extra fluid which had to be
dumped from the brakes. This is done to prevent the
wheels from locking up. The pump provides the fluid
volume needed and is operated by a DC type motor.
The motor is controlled by the CAB.
During normal braking, the HCU solenoid valves
and pump are not activated. The master cylinder and
power booster operate the same as a vehicle without
an ABS brake system.
The valve body contains the solenoid valves. The
valves modulate brake pressure during antilock brak-
ing and are controlled by the CAB.
The HCU provides three channel pressure control
to the front and rear brakes. One channel controls
the rear wheel brakes in tandem. The two remaining
channels control the front wheel brakes individually.
Fig. 6 Rear Speed Sensor Mounting
1 - WHEEL SPEED SENSOR
2 - AXLE
5 - 40 BRAKES - ABSBR/BE
FRONT WHEEL SPEED SENSOR (Continued)

In addition to reducing wire harness complexity,
component sensor current loads and controller hard-
ware, multiplexing offers a diagnostic advantage. A
multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. The DaimlerChrysler system allows an
electronic control module to broadcast message data
out onto the bus where all other electronic control
modules can ªhearº the messages that are being sent.
When a module hears a message on the data bus
that it requires, it relays that message to its micro-
processor. Each module ignores the messages on the
data bus that are being sent to other electronic con-
trol modules.
With a diagnostic scan tool connected into the CCD
circuit, a technician is able to observe many of the
electronic control module function and message out-
puts while; at the same time, controlling many of the
sensor message inputs. The CCD data bus, along
with the use of a DRBIIItdiagnostic scan tool and a
logic-based approach to test procedures, as found in
the appropriate diagnostic procedures manuals,
allows the trained automotive technician to more eas-
ily, accurately and efficiently diagnose the many com-
plex and integrated electronic functions and features
found on today's vehicles.
OPERATION - CCD DATA BUS
The CCD data bus system was designed to run at a
7812.5 baud rate (or 7812.5 bits per second). In order
to successfully transmit and receive binary messages
over the CCD data bus, the system requires the fol-
lowing:
²Bus (+) and Bus (±) Circuits
²CCD Chips in Each Electronic Control Module
²Bus Bias and Termination
²Bus Messaging
²Bus Message Coding
Following are additional details of each of the
above system requirements.
BUS (+) AND BUS (±) CIRCUITS
The two wires (sometimes referred to as the ªtwist-
ed pairº) that comprise the CCD data bus are the D1
circuit [Bus (+)], and the D2 circuit [Bus (±)]. The9D9
in D1 and D2 identify these as diagnostic circuits.
Transmission and receipt of binary messages on the
CCD data bus is accomplished by cycling the voltage
differential between the Bus (+) and Bus (±) circuits.
The two data bus wires are twisted together in
order to shield the wires from the effects of any Elec-
tro-Magnetic Interference (EMI) from switched volt-
age sources. An induced EMI voltage can be
generated in any wire by a nearby switched voltage
or switched ground circuit. By twisting the data bus
wires together, the induced voltage spike (either upor down) affects both wires equally. Since both wires
are affected equally, a voltage differential still exists
between the Bus (+) and Bus (±) circuits, and the
data bus messages can still be broadcast or received.
The correct specification for data bus wire twisting is
one turn for every 44.45 millimeters (1 ô inches) of
wire.
CCD CHIPS
In order for an electronic control module to commu-
nicate on the CCD data bus, it must have a CCD
chip (Fig. 5). The CCD chip contains a differential
transmitter/receiver (or transceiver), which is used to
send and receive messages. Each module is wired in
parallel to the data bus through its CCD chip.
The differential transceiver sends messages by
using two current drivers: one current source driver,
and one current sink driver. The current drivers are
matched and allow 0.006 ampere to flow through the
data bus circuits. When the transceiver drivers are
turned On, the Bus (+) voltage increases slightly, and
the Bus (±) voltage decreases slightly. By cycling the
drivers On and Off, the CCD chip causes the voltage
on the data bus circuit to fluctuate to reflect the mes-
sage.
Once a message is broadcast over the CCD data
bus, all electronic control modules on the data bus
have the ability to receive it through their CCD chip.
Reception of CCD messages is also carried out by the
transceiver in the CCD chip. The transceiver moni-
tors the voltage on the data bus for any fluctuations.
When data bus voltage fluctuations are detected,
they are interpreted by the transceiver as binary
messages and sent to the electronic control module's
microprocessor.
Fig. 5 CCD Chip
BR/BEELECTRONIC CONTROL MODULES 8E - 7
COMMUNICATION (Continued)