reset CHEVROLET DYNASTY 1993 User Guide

² To set DAY of WEEK, press TIME button. An ar-
row will appear on the display and point to the Day.
Press and hold the SET button to move the day for-
ward or INFO button to move it backward.
² To set DAY of MONTH, press TIME button. The
arrow will point to Date. Press and hold the SET
button to advance the date or INFO button to move
it backwards.
² To set MONTH of YEAR, press TIME button. The
arrow will point to the Month. Press and hold the
SET button to advance the Month forward or INFO
button to move backward. TEMP button, pressing the Temp button will dis-
play:
² The temperature outside the vehicle
² Vehicle direction define by an eight point compass
If Compass has lost calibration or not receiving
good information from the engine compartment node,
an asterisk (*) will flash on the display and the word
calibrate will appear. Refer to Compass Calibration. FUEL BUTTON, WILL DISPLAY:
² Pressing FUEL button the first time will show, the
estimated number of miles that can be driven with
the remaining fuel. The destination to empty indica-
tion will vary every few seconds as the amount of
fuel and fuel efficiency is calculated. This function
can not be reset.
² Pressing the FUEL button second time; will dis-
play the fuel consumed.
²
Pressing the FUEL button third time; will display
the average fuel economy in miles per gallon since last
reset. The display will be updated every 16 seconds.
² Pressing the FUEL button forth time, the current
fuel economy will be displayed. The current fuel
economy will be up updated every two seconds.
² To reset Fuel consumed, press SET button until
the fuel consumed message is displayed and then
within five seconds press SET button.
² To reset AVERAGE FUEL ECONOMY, press the
FUEL button until average fuel economy is displayed
and within five seconds press SET button. TRIP RESET, press FUEL button and wait four
seconds press the SET button twice. This clears all
trip information and the message Trip Reset will be
displayed. This will occur only if a reset function is
currently being displayed. The reset functions:
² Fuel consumed
² Average fuel economy message
INFO button, will active a MONITORED SYS-
TEMS OK message on display if all monitored sys-
tems are operating properly. If a problem is detected,
the appropriate message will be displayed. SET button, will clear the various functions after
they have been displayed. It is used to enter the
clock set or compass variance modes. This button is
also used to reset certain trip computer functions and
the maintenance reminder message.
The EVIC display may be turned off by pressing the
TIME and SET buttons at the same time. Pressing the
buttons a second time will restore the display.
EVIC INFORMATION SOURCES
The EVIC monitors information provided by the
body controller, engine compartment node and pow-
ertrain control module. Refer to Body Diagnostic Test
Procedure Manual for test procedures. The Body Controller is a micro-controller unit
which, informs the EVIC overhead console via the
CCD bus of:
² Time of day
² Day of week
² Day of month
² Month of year
² Fuel range
² Fuel consumed
² Fuel efficiency
² Warning messages as noted in Fig. 2
The Engine Compartment Node is a microcomputer
controlled unit which, informs the EVIC overhead
console via the CCD bus of:
² Outside temperature
² Compass direction
THE FOLLOWING ARE WARNING MESSAGES:
² Low brake fluid
² Low coolant level
² Low engine oil level
The powertrain control module is a microcomputer
controlled unit which, informs the EVIC overhead con-
sole via the CCD bus of the following warning messages:
² Engine temperature high
² Voltage improper
Fig. 2 EVIC Messages and Sensors
Ä OVERHEAD CONSOLE 8C - 7

BUS ACCESSED DIAGNOSTICS
The following diagnostic test may be used to check
the integrity of the EVIC's internal connections and
operations. Refer to the Body Chassis Diagnostic Test
Procedure Manual for test procedures. MODULE RESET TEST, when the EVIC receives
this request from the DRB II, the EVIC will immedi-
ately enter into reset. DISPLAY TEST: The EVIC receives a request from
the DBR II, the EVIC will enter into a visual display
mode. Also checks the integrity of the display driver
to anode connections. The test shall consist of walk-
ing through the vertical and horizontal rows of an-
odes in the dot matrix display. SWITCH STATUS TEST, when the EVIC receives
this request from the DRB II, the EVIC will report
the open/closed status of each individual switch. FAULT BYTE TEST, when the EVIC receives this
request from the DRB II, the EVIC will report fault
status. Messages reported are:
² NO FAULT
² DISPLAY DRIVER FAULT
² EVIC MISSING MESSAGES
² POWER SUPPLY FAILURE
² FAULT IN RAM
² FAULT IN ROM
EVIC missing message implies that there may be a
system failure and/or the body controller is not pro-
viding EVIC with sufficient information. DISPLAY DRIVER FAULT, power supply failure
and fault in RAM/ROM implies that the EVIC is de-
fective.
CONSOLE REMOVAL
(1) Remove lenses (Fig. 4).
(2) Remove screws from visor tip-pin retainers.
(3) Remove screws in lens openings, after remov-
ing lamps. (4) Remove console and disconnect wires.
(5) For installation reverse above procedures.
ELECTRONIC BOARD ASSEMBLY REPLACEMENT
(1) Remove console, refer to Console Replacement
(Fig. 5).
(2) Remove six mounting screws holding bezel to
housing. (3) Remove switch assembly by pulling down
mounting tabs and swing assembly out of position. (4) Disconnect switch wiring connector and replace
electronic board assembly. (5) For installation reverse above procedures.
BEZEL/BUTTON SWITCH REMOVAL
(1) Remove console, refer to Console Replacement.
(2) Remove six mounting screws holding bezel to
housing. (3) Remove switch assembly by pulling down
mounting tabs and swing assembly out of position. (4) Disconnect switch wiring connector and remove
electronic board and switch assembly. Replace func-
tion button switch assembly. The buttons are not ser-
viceable. (5) For installation reverse above procedures.
WIRING HARNESS REMOVAL
(1) Remove console, refer to Console Replacement
(Fig. 6). (2) Disconnect wiring connector from retaining
bracket. (3) Remove screws, securing wiring to console
housing. (4) Remove push/slide switches. The reading lamp
switch buttons are not serviceable. (5) Remove lamp sockets from reflector bracket.
(6) Remove wiring.
(7) For installation reverse above procedures.
Fig. 4 EVIC Overhead Console Lens Removal
Fig. 5 EVIC Overhead Console
8C - 10 OVERHEAD CONSOLE Ä

dition exists. These messages are displayed on the
center of the instrument panel.For complete EVIC operating instructions, refer to
the Owners Manual provided with the vehicle.
EVIC BUTTON FUNCTIONS
TIME button will display:
² Time of day
² Day of week
² Day of month
² Month of year
² To set HOURS, press TIME button and within four
seconds press the SET button. An arrow will appear
on the display and point to the hours. Press and hold
the SET button to advance the hours or INFO button
to set back the hours.
² To set MINUTES, press TIME button. The arrow
will point to the minutes. Press and hold the SET
button to advance the minutes or INFO button to set
back the minutes.
² To set DAY of WEEK, press TIME button. An ar-
row will appear on the display and point to the Day.
Press and hold the SET button to move the day for-
ward or INFO button to move it backward.
² To set DAY of MONTH, press TIME button. The
arrow will point to Date. Press and hold the SET
button to advance the date or INFO button to move
it backwards.
² To set MONTH of YEAR, press TIME button. The
arrow will point to the Month. Press and hold the
SET button to advance the Month forward or INFO
button to move backward. TEMP button, pressing the Temp button will dis-
play:
² The temperature outside the vehicle
² Vehicle direction define by an eight point compass
If Compass has lost calibration or not receiving
good information from the engine compartment node,
an asterisk (*) will flash on the display and the word
calibrate will appear. Refer to Compass Calibration. FUEL BUTTON, WILL DISPLAY:
² Pressing FUEL button the first time will show, the
estimated number of miles that can be driven with
the remaining fuel. The destination to empty indica-
tion will vary every few seconds as the amount of
fuel and fuel efficiency is calculated. This function
can not be reset.
² Pressing the FUEL button second time; will dis-
play the fuel consumed.
² Pressing the FUEL button third time; will display
the average fuel economy in miles per gallon since
last reset. The display will be updated every 16 sec-
onds.
² Pressing the FUEL button forth time, the current
fuel economy will be displayed. The current fuel
economy will be up updated every two seconds. ²
To reset Fuel consumed, press SET button until
the fuel consumed message is displayed and then
within five seconds press SET button.
² To reset AVERAGE FUEL ECONOMY, press the
FUEL button until average fuel economy is displayed
and within five seconds press SET button. TRIP RESET, press FUEL button and wait four
seconds press the SET button twice. This clears all
trip information and the message Trip Reset will be
displayed. This will occur only if a reset function is
currently being displayed. The reset functions:
² Fuel consumed
² Average fuel economy message
INFO button, will active a MONITORED SYS-
TEMS OK message on display if all monitored sys-
tems are operating properly. If a problem is detected,
the appropriate message will be displayed. SET button, will clear the various functions after
they have been displayed. It is used to enter the
clock set or compass variance modes. This button is
also used to reset certain trip computer functions and
the maintenance reminder message. The EVIC display may be turned off by pressing
the TIME and SET buttons at the same time. Press-
ing the buttons a second time will restore the dis-
play.
EVIC INFORMATION SOURCES
The EVIC monitors information provided by the
body controller, engine compartment node and pow-
ertrain control module. Refer to Body Diagnostic Test
Procedure Manual for test procedures. The Body Controller is a micro-controller unit
which, informs the EVIC via the CCD bus of:
² Time of day
² Day of week
² Day of month
² Month of year
² Fuel range
² Fuel consumed
² Fuel efficiency
² Warning messages as noted in Fig. 3.
The Engine Compartment Node is a microcomputer
controlled unit which, informs the EVIC via the CCD
bus of:
² Outside temperature
² Compass direction
THE FOLLOWING ARE WARNING MESSAGES:
² Low brake fluid
² Low coolant level
² Low engine oil level
The powertrain control module is a microcomputer
controlled unit which, informs the EVIC via the CCD
bus of the following warning messages:
² Engine temperature high
² Voltage improper
8C - 14 OVERHEAD CONSOLE Ä

off, there should be continuity in the system. Start
the engine. With the engine running, the ohmmeter
should show no continuity. If the above results are
not obtained, replace the switch.
BRAKE SYSTEM WARNING LAMP
The brake warning lamp illuminates when parking
brake is applied with ignition key turned ON. The
same lamp will also illuminate should one of the two
service brake systems fail when brake pedal is ap-
plied. To test system turn ignition key ON, and ap-
ply parking brake. If lamp fails to light, inspect for a
burned out lamp, disconnected socket, a broken or
disconnected wire at switch. The lamp also lights
when the ignition switch is turned to START. To test service brake warning system, raise vehicle
on a hoist and open a wheel cylinder bleeder while a
helper depresses brake pedal and observes warning
light. If lamp fails to light, inspect for a burned out
lamp, disconnected socket, a broken or disconnected
wire at switch. If lamp is not burned out and wire continuity is
proven, replace brake warning switch in brake line
Tee fitting mounted on frame rail in engine compart-
ment below master cylinder (Fig.6 and 7). CAUTION: If wheel cylinder bleeder was opened
check master cylinder fluid level.
SEAT BELT WARNING LAMP
For testing of this system, refer to Group 8M, Re-
straint System.
MALFUNCTION INDICATOR (CHECK ENGINE) LAMP
For testing of this system, refer to the Powertrain
Diagnostic Test Procedure Manual.
MECHANICAL/ELECTRONIC CLUSTER REMOVAL
CLUSTER BEZELS REMOVAL
(1) Move gear selector to the low position.
(2) Remove five screws attaching upper bezel to in-
strument panel (Fig. 8). (3) Lift cluster bezel over steering wheel.
(4) Remove four screws attaching lower bezel to in-
strument panel. (5) Lift lower cluster bezel from instrument panel.
(6) For installation reverse above procedures.
CLUSTER MASK AND LENS REMOVAL
(1) Remove cluster bezel.
(2) Remove trip reset knob by pulling straight
back. (3) Remove five screws attaching mask and lens to
cluster. (4) For installation reverse above procedures.
Fig. 4 Combination Oil Sending Unit
Fig. 5 Combination Oil Sending Unit Test
Fig. 6 Brake Warning Lamp Switch
Ä INSTRUMENT PANEL AND GAUGES 8E - 25

CONDITION: US/METRIC MODES WILL NOT TOGGLE OR TRIP ODOMETER WILL NOTRESET
PROCEDURE
(1) Perform cluster self-diagnostics to determine if
push buttons are operational. (2) Refer to the Body Chassis Diagnostic Manual
to diagnose CCD Bus. The US/Metric toggle and trip
odometer reset are activated over the CCD Bus.
ODOMETER ADJUSTMENT
The odometer memory is no longer retained in the
cluster. This information is stored in the body con-
troller. Therefore, there is no adjustment procedure.
If the cluster is replaced odometer value will not
change. If the body controller is replaced the mileage
may be transferred using the DRB II. Refer to the
Body Chassis Diagnostic Manual for the procedure.
SWITCH AND PANEL COMPONENT SERVICE
MESSAGE CENTER REPLACEMENT
(1) Remove upper cluster bezel (Fig. 32).
(2) Remove two attaching screws (Fig. 33).
(3) Disconnect wiring connector and remove mes-
sage center. (4) For installation reverse above procedures.AIR CONDITIONING CONTROLREPLACEMENT
(1) Remove upper cluster bezel (Fig. 32).
(2) Remove two control mounting screws.
Fig. 31 Cluster Connector
Fig. 32 Cluster Bezel
Ä INSTRUMENT PANEL AND GAUGES 8E - 37

(2) The headlamps and parking lamps should turn
ON for about five seconds.
² AUTO MIRROR LED
² DARK LED
² AUTO LAMP LED
² The LED indicators blink for about 5 seconds.
² If the three indicators continue to blink consider-
ably longer than 5 seconds, then the mirror assembly
is defective. (3) The mirror should change to dim state.(a) Place shift selector in reverse (R), with igni-
tion switch ON:
² AUTO MIRROR LED indicator ON
² DARK LED indicator flashing
² Lasting about 15 seconds
(b) The mirror should slowly change to bright
state. (c) If the ignition is not turned OFF within the
15 second time period, the mirror will reset to its
previous setting.
The previous conditions are OK, the mirror is op-
erating properly. If not OK, continue with voltage tests below.
VOLTAGE TEST
To test for voltage insert voltmeter probe into wire
end of connector to contact terminal. Pin 1 ignition voltage (a) Ignition switch OFF, zero volts.
(b) Ignition switch ON, battery voltage.
Pin 2 battery voltage (a) Battery voltage at all times.
(b) No voltage, check 15 amp. fuse.
Pin 3 Ground (a) Continuity to ground.
(b) No voltage
Pin 4 Reverse over-ride (a) Ignition OFF, zero voltage.
(b) Ignition ON shift selector in Reverse (R), bat-
tery voltage. (c) Ignition ON shift selector in any position
other than Reverse (R), zero voltage.
Pin 5 Headlamp relay (a) Battery voltage at all times from headlamp
relay. (b) No battery voltage, test headlamp relay.
Pin 6 Park lamp relay (a) Ignition switch ON, battery voltage feed from
park lamp relay. (b) Ignition switch OFF, zero voltage.
(c) Ignition ON, No battery voltage test park
lamp relay.
If Voltage Test are OK, replace mirror assembly.
If not OK, refer to Wiring Diagrams manual.
8T - 8 POWER MIRRORS Ä

(5) Reset the terminal locking tang, if it has one.
(6) Insert the removed wire in the same cavity on
the repair connector. (7) Repeat steps four thru six for each wire in the
connector. Check that all wires are inserted into the
proper cavities. For connector pin out identification
refer to the wiring diagrams. (8) Insert the connector locking wedge into the re-
paired connector. (9) Connect connector to its mating half.
(10) Connect battery and test all affected systems.
CONNECTOR AND TERMINAL ASSEMBLY REPLACEMENT
(1) Disconnect Battery.
(2) Disconnect the connector being repaired form
its mating half. (3) Cut off the existing wire connector directly be-
hind the insulator. Remove six inches of tape from
the harness. (4) Stagger cut all wires on the harness side about
1/2 inch apart (Fig. 14). (5) Remove 1 inch of insulation from each wire on
the harness side. (6) Stagger cut the matching wires on the repair
connector assembly in the opposite order as was done
on the harness side of the repair. Allow extra length
for soldered connections. Check that the overall
length is the same as the original (Fig. 14). (7) Remove 1 inch of insulation from each wire.
(8) Place a piece of heat shrink tubing over one
side of the wire. Make sure the tubing will be long
enough to cover and seal the entire repair area. (9) Spread the strands of the wire apart on each
part of the exposed wires (Fig. 11 example 1). (10) Push the two ends of wire together until the
strands of wire are close to the insulation (Fig. 11 ex-
ample 2). (11) Twist the wires together (Fig. 11 example 3). (12) Solder the connection together using rosin
core type solder only. Do not use acid core solder.
(13) Center the heat shrink tubing over the joint
and heat using a heat gun. Heat the joint until the
tubing is tightly sealed and sealant comes out of both
ends of the tubing. (14) Repeat steps 8 thru 13 for each wire.
(15) Re-tape the wire harness starting 1-1/2 inches
behind the connector and 2 inches past the repair. (16) Reconnect the repaired connector.
(17) Connect battery and test all affected systems.
TERMINAL REPLACEMENT
(1) Disconnect battery.
(2) Disconnect the connector being repaired form
its mating half. (3) Remove connector locking wedge (Fig. 12).
(4) Position the connector locking finger away from
the terminal. Pull on the wire to remove the termi-
nal from the connector (Fig. 13). (5) Cut the wire 6 inches from the back of the con-
nector. (6) Remove 1 inch of insulation from the wire on
the harness side. (7) Select a wire from the terminal repair assem-
bly that best matches the color wire being repaired. (8) Cut the repair wire to the proper length and re-
move 1 inch of insulation. (9) Place a piece of heat shrink tubing over one
side of the wire. Make sure the tubing will be long
enough to cover and seal the entire repair area. (10) Spread the strands of the wire apart on each
part of the exposed wires (Fig. 11 example 1). (11) Push the two ends of wire together until the
strands of wire are close to the insulation (Fig. 11 ex-
ample 2). (12) Twist the wires together (Fig. 11 example 3).
(13) Solder the connection together using rosin
core type solder only. Do not use acid core solder.
Fig. 13 Connector Locking Finger and Locking
Wedge
Fig. 14 Stagger Cutting Wires
8W - 6 GENERAL INFORMATION Ä

POWER STEERING/ACCESSORY DRIVE BELT TENSIONER BRACKET
REMOVAL
(1) Remove Accessory Drive Belt. Refer to Cooling
System Group 7 for procedure. (2) Remove accessory drive belt tensioner pulley
(Fig. 7). (3) Remove Timing Belt covers. Refer to procedure
outlined in this section. (4) Remove Power Steering Pump bolts set pump
aside (Fig. 11). (5) Loosen timing belt tension. Refer to Camshaft
and Crankshaft Timing Service for procedure. Re-
move timing belt idler pulley bolt (Fig. 12).
CAUTION: Camshaft and Crankshaft Timing may
have to be reset when procedure is completed Refer
to procedure outlined in this section.
Fig. 8 Solid Mount Compressor BracketÐTurbo III Engine
Fig. 9 Accessory Drive Idler Pulley Bracket and Engine StrutFig. 10 Compressor Bracket to Cylinder HeadAttaching Bolts
9 - 16 2.2/2.5L ENGINE Ä

(2) Turn camshaft until arrows on hub are inline
with No. 1 camshaft cap to cylinder headline. Small
hole (arrow Fig. 12) must be in vertical center line. (3) Install timing belt.
(4) Rotate crankshaft two full revolutions and re-
check timing.
CAUTION: Do not allow oil or solvents to contact
the timing belt as they can deteriorate the rubber
and cause tooth skipping.
(5) Rotate crankshaft till number 1 cylinder is at
the TDC position. (6) Put belt tension Special Tool C-4703 horizon-
tally on large hex of timing belt tensioner pulley and
loosen tensioner lock nut. (7) Reset belt tension Special Tool C-4703 index if
necessary to have axis within 15É of horizontal. (Fig.
13) (8) Turn engine clockwise from TDC two crank revo-
lutions to TDC. Do not reverse rotate crankshaft
or attempt to rotate engine using cam or acces-
sory shaft attaching screw. (9) Hold weighted wrench in position while tighten-
ing bolt on tensioner to 61 N Im (45 ft. lbs.) torque.
(10) Lower engine onto engine mount install mount-
ing bolts and tighten to specifications refer to (Fig. 3). (11) Remove jack from under engine.
(12) Inspect foam stuffer block condition and posi-
tion (Fig. 14). Stuffer block should be intact and secure
within the engine bracket tunnel. (13) Position both halves of timing belt cover to-
gether (Fig. 4). (14) Install fasteners holding cover to cylinder head
and block. Tighten fasteners to 4 N Im (40 in. lbs.)
torque. (15) Valve Timing Check; (timing belt cover in-
stalled). With number one cylinder at TDC, small hole
in sprocket must be centered in timing belt cover hole
(Fig. 12). If hole is not aligned correctly perform
procedure again. (16) Install spark plugs.
Fig. 12 Camshaft Timing
Fig. 13 Adjusting Drive Belt Tension
Fig. 14 Foam Stuffer Block Location
Ä 2.2/2.5L ENGINE 9 - 21

TACHOMETERÐPCM OUTPUT
The PCM supplies engine RPM to the instrument
panel tachometer. Refer to Group 8 for tachometer
information.
MODES OF OPERATION
As input signals to the PCM change, the PCM
adjusts its response to the output devices. For example,
the PCM must calculate a different injector pulse
width and ignition timing for idle than it does for wide
open throttle (WOT). There are several different modes
of operation that determine how the PCM responds to
the various input signals. There are two different areas of operation, OPEN
LOOP and CLOSED LOOP. During OPEN LOOP modes, the PCM receives input
signals and responds according to preset PCM pro-
gramming. Input from the oxygen (O
2) sensor is not
monitored during OPEN LOOP modes. During CLOSED LOOP modes, the PCM does moni-
tor the oxygen (O
2) sensor input. This input tells the
PCM if the calculated injector pulse width results in an
air-fuel ratio of 14.7 to 1. By monitoring the exhaust
oxygen content, the can PCM fine tune injector pulse
width for optimum fuel economy and low emissions. The single point fuel injection system has the follow-
ing modes of operation:
² Ignition switch ON - Zero RPM
² Engine start-up
² Engine warm-up
² Cruise (Idle)
² Acceleration
² Deceleration
² Wide Open Throttle
² Ignition switch OFF
The engine start-up (cranking), engine warm-up, and
wide open throttle modes are OPEN LOOP modes. The
acceleration, deceleration, and cruise modes, with the
engine at operating temperature are CLOSED
LOOP modes (under most operating conditions).
IGNITION SWITCH ON (ZERO RPM) MODE
When the single point fuel injection system is acti-
vated by the ignition switch, the following actions
occur:
² The PCM determines atmospheric air pressure from
the MAP sensor input to calculate basic fuel strategy.
² The PCM monitors the coolant temperature sensor
and throttle position sensor inputs. The PCM modifies
fuel strategy based on these inputs. When the key is in the ON position and the engine is
not running, the (ASD) and fuel pump relays are not
energized. Therefore, battery voltage is not supplied to
the fuel pump, ignition coil, fuel injector or oxygen
sensor heating element. ENGINE START-UP MODE
This is an OPEN LOOP mode. The following actions
occur when the starter motor is engaged. If the PCM receives a distributor signal it energizes
the auto shutdown (ASD) relay and fuel pump relay to
supply battery voltage to the fuel injector, ignition coil
and oxygen sensor heating element. If the PCM does
not receive a distributor input, it de-energizes the ASD
and fuel pump relays after approximately one second. When the engine idles within 664 RPM of the target
RPM, the PCM compares the current MAP value with
the atmospheric pressure value it received during the
Ignition Switch On (Zero RPM) Mode. If a minimum
difference between the two is not detected, a MAP
sensor fault is set into memory. Once the ASD relay and fuel pump relay have ener-
gized, the PCM:
² Supplies a ground path to the injector. The injector
is pulsed four times per engine revolution instead of
the normal two pulses per revolution.
² Determines injector pulse width based on coolant
temperature, MAP sensor input, throttle position, and
the number of engine revolutions since cranking was
initiated.
² Monitors the coolant temperature sensor, distribu-
tor pick-up, MAP sensor, and throttle position sensor to
determine correct ignition timing.
ENGINE WARM-UP MODE
This is a OPEN LOOP mode. The following inputs
are received by the PCM:
² coolant temperature
² manifold absolute pressure (MAP)
² engine speed (distributor pick-up)
² throttle position
² A/C switch
² battery voltage
The PCM provides a ground path for the injector to
precisely control injector pulse width (by switching the
ground on and off) and fires the injector twice per
engine revolution. The PCM regulates ignition timing.
It also adjusts engine idle speed through the idle air
control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this is
a CLOSED LOOP mode. During cruising speed and at
idle the following inputs are received by the PCM:
² coolant temperature
² manifold absolute pressure
² engine speed
² throttle position
² exhaust gas oxygen content
² A/C control positions
² battery voltage
14 - 32 FUEL SYSTEMS Ä