2000 CHRYSLER VOYAGER Diagnostic Manual

EURO STAGE III OBD MONITOR INFORMATION
Comprehensive Major Monitors Major Monitors
Components Non Fuel Control Fuel Control
Monitor & Non Misfire & Misfire
Run constantly Run Once Per Trip Run Constantly
Includes All Engine Hardware Monitors Entire Emission Monitors Entire System
- Sensors, Switches, System
Solenoids, etc.
One Trip Faults - Turns On Two Trip Faults - Turns On Two Trip Faults - Turns On
The MIL and Sets DTC After The MIL and Sets DTC After The MIL and Sets DTC After
One Failure (except for most ra-
tionality tests which are two trip)Two Consecutive Failures Two Consecutive Failures
Priority 3 Priority 1 or 3 Priority 2 or 4
All Checked For Continuity Done Stop Testing = Yes
Fuel Control Monitor
Open Monitors Fuel Control
Short To Ground Oxygen Sensor Heater System For:
Short To Voltage Oxygen Sensor Response
Fuel System Lean
Fuel System Rich
Inputs Checked For
Requires 3 Consecutive Rationality
Catalytic Converter
Fuel System Good TripsTo Efficiency Except EWMA
Extinguish The MIL Outputs Checked For - up to 6 tests per trip
Functionality and a one trip fault
EGR System
Misfire Monitor
Monitors For Engine Misfire
at:
1000 RPM Counter
(Type B)
**200 RPM Counter
(Type A)
Requires 3 Consecutive Requires 3 Consecutive Requires 3 Consecutive
Global/Alternate Good Trips Global Good Trips Misfire Good Trips
to Extinguish the MIL* to Extinguish the MIL* To Extinguish the MIL
*40 Warm Up Cyclesare required to erase **Type A misfire is a one
DTC's
afterthe MIL has been extinguished. trip failure. The MIL will
illuminate and blink at
the first failure.
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3.2.3 OTHER CONTROLS
CHARGING SYSTEM
The charging system is turned on when the
engine is started and ASD relay energized. When
the ASD relay is on, ASD output voltage is supplied
to the ASD sense circuit at the PCM. This voltage is
connected in some cases, through the PCM and
supplied to one of the generator field terminals
(Gen Source +). All others, the Gen field is con-
nected directly to the ASD output voltage. The
amount of current produced by the generator is
controlled by the Electronic Voltage Regulator
(EVR) circuitry, in the PCM. A battery temperature
sensor, located either in the battery tray, using the
ambient sensor, or in the PCM itself, is used to
sense battery temperature. This temperature along
with sensed line voltage, is used by the PCM to vary
the battery charging rate. This is done by cycling
the ground path to the other generator field termi-
nal (Gen field driver).
SPEED CONTROL SYSTEM
The PCM controls vehicle speed by operation of
the speed control servo vacuum and vent solenoids.
Energizing the vacuum solenoid applies vacuum to
the servo to increase throttle position. Operation of
the vent solenoid slowly releases the vacuum allow-
ing throttle position to decrease. A special dump
solenoid allows immediate release of throttle posi-
tion caused by braking, cruise control switch turned
off, shifting into neutral, excessive RPM (tires spin-
ning) or ignition key off.
3.2.4 PCM OPERATING MODES
As input signals to the powertrain control module
(PCM) change, the PCM adjusts its response to
output devices. For example, the PCM must calcu-
late a different injector pulse width and ignition
timing for idle than it does for wide open throttle.
There are several different modes of operation that
determine how the PCM responds to the various
input signals.
There are two types of engine control operation:
open loopandclosed loop.
In open loop operation, the PCM receives input
signals and responds according to preset program-
ming. Inputs from the heated oxygen sensors are
not monitored.
In closed loop operation, the PCM monitors the
inputs from the heated oxygen sensors. This input
indicates to the PCM whether or not the calculated
injector pulse width results in the ideal air-fuel
ratio of 14.7 parts air to 1 part fuel. By monitoring
the exhaust oxygen content through the oxygen
sensor, the PCM can fine tune injector pulse width.
Fine tuning injector pulse width allows the PCM toachieve the lowest emission levels while maintain-
ing optimum fuel economy.
The engine start-up (crank), engine warm-up,
and wide open throttle modes are open loop modes.
Under most operating conditions, closed loop modes
occur with the engine at operating temperature.
IGNITION SWITCH ON (ENGINE OFF) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
1. The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic
fuel strategy.
2. The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input.
The PCM modifies fuel strategy based on this
input.
When the key is in the ªonº position and the
engine is not running (zero rpm), the auto shut-
down relay and fuel pump relay are not energized.
Therefore, voltage is not supplied to the fuel pump,
ignition coil, and fuel injectors.
Engine Start-up Mode -This is an open loop
mode. The following actions occur when the starter
motor is engaged:
1. The auto shutdown and fuel pump relays are
energized. If the PCM does not receive the cam-
shaft and crankshaft signal within approxi-
mately one second, these relays are de-
energized.
2. The PCM energizes all fuel injectors until it
determines crankshaft position from the cam-
shaft and crankshaft signals. The PCM deter-
mines crankshaft position within one engine
revolution. After the crankshaft position has
been determined, the PCM energizes the fuel
injectors in sequence. The PCM adjusts the in-
jector pulse width and synchronizes the fuel
injectors by controlling the fuel injectors' ground
paths.
3. Once the engine idles within 64 rpm of its target
engine speed, the PCM compares the current
MAP sensor value with the value received dur-
ing the ignition switch on (zero rpm) mode. A
diagnostic trouble code is written to PCM mem-
ory if a minimum difference between the two
values is not found.
Once the auto shutdown and fuel pump relays
have been energized, the PCM determines the fuel
injector pulse width based on the following:
± engine coolant temperature
± manifold absolute pressure
± intake air temperature
± engine revolutions
± throttle position
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The PCM determines the spark advance based on
the following:
± engine coolant temperature
± crankshaft position
± camshaft position
± intake air temperature
± manifold absolute pressure
± throttle position
Engine Warm-Up Mode -This is an open loop-
mode. The PCM adjusts injector pulse width and
controls injector synchronization by controlling the
fuel injectors' ground paths. The PCM adjusts igni-
tion timing and engine idle speed. The PCM adjusts
the idle speed by controlling the idle air control
motor and spark advance.
Cruise or Idle Mode -When the engine is at
normal operating temperature, this is a closed loop
mode.
Acceleration Mode -This is a closed loop mode.
The PCM recognizes an increase in throttle position
and a decrease in manifold vacuum as engine load
increases. In response, the PCM increases the in-
jector pulse width to meet the increased load. The
A/C compressor may be de-energized for a short
period of time.
Deceleration -This is a closed loop mode. The
PCM recognizes a decrease in throttle position and
an increase in manifold vacuum as engine load
decreases. In response, the PCM decreases the
injector pulse width to meet the decreased load.
Full injector shut off may be obtained during high
speed deceleration.
Wide Open Throttle Mode -This is an open
loop mode. The throttle position sensor notifies the
PCM of a wide open throttle condition. Once a wide
open throttle is sensed, the PCM de-energizes the
A/C compressor clutch relay for 15 seconds.
3.2.5 NON-MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems, and conditions even though they could
have malfunctions that result in driveability prob-
lems. A diagnostic code may not be displayed for the
following conditions. However, problems with these
systems may cause a diagnostic code to be displayed
for other systems. For example, a fuel pressure
problem will not register a diagnostic code directly,
but could cause a rich or lean condition. This could
cause an oxygen sensor, fuel system, or misfire
monitor trouble code to be stored in the PCM.
Engine Timing -The PCM cannot detect an
incorrectly indexed timing chain, camshaft
sprocket, or crankshaft sprocket. The PCM also
cannot detect an incorrectly indexed distributor.(*)
Fuel Pressure -Fuel pressure is controlled by
the fuel pressure regulator. The PCM cannot detecta clogged fuel pump inlet filter, clogged in-line filter,
or a pinched fuel supply.(*)
Fuel Injectors -The PCM cannot detect if a fuel
injector is clogged, the pintle is sticking, or the
wrong injectors are installed.(*)
Fuel Requirements -Poor quality gasoline can
cause problems such as hard starting, stalling, and
stumble. Use of methanol-gasoline blends may re-
sult in starting and driveability problems. See indi-
vidual symptoms and their definitions in Section
6.0 (Glossary of Terms)
PCM Grounds -The PCM cannot detect a poor
system ground. However, a diagnostic trouble code
may be stored in the PCM as a result of this
condition.
Throttle Body Air Flow -The PCM cannot
detect a clogged or restricted air cleaner inlet or
filter element.(*)
Exhaust System -The PCM cannot detect a
plugged, restricted, or leaking exhaust system.(*)
Cylinder Compression -The PCM cannot de-
tect uneven, low, or high engine cylinder compres-
sion.(*)
Excessive Oil Consumption -Although the
PCM monitors the exhaust stream oxygen content
through the oxygen sensor when the system is in a
closed loop, it cannot determine excessive oil con-
sumption.
(*)NOTE: ANY OF THESE CONDITIONS
COULD RESULT IN A RICH OR LEAN
CONDITION CAUSING AN OXYGEN SENSOR
TROUBLE CODE TO BE STORED IN THE
PCM, OR THE VEHICLE MAY EXHIBIT ONE
OR MORE OF THE DRIVEABILITY
SYMPTOMS LISTED IN THE TABLE OF
CONTENTS.
3.2.6 SKIS OVERVIEW
The Sentry Key Immobilizer System (SKIS) is an
immobilizer system design to prevent unauthorized
vehicle operation. The system consists of a Sentry
Key Immobilizer Module (SKIM), ignition key(s)
equipped with a transponder chip and engine con-
troller. When the ignition switch is turned on, the
SKIM interrogates the ignition key. If the ignition
key is ``Valid'', the SKIM sends a CCD Bus message
to the engine controller indicating the presence of a
valid igntion key. Upon receiving a ``Valid'' key
signal the PCM will allow the engine to continue to
operate.
3.2.7 SKIM ON-BOARD DIAGNOSTICS
The SKIM has been programmed to transmit and
monitor many different coded messages as well as
CCD Bus messages. This monitoring is called ``On
Board Diagnosis''.
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Certain criteria must be met for a diagnostic
trouble code to be entered into the SKIM memeory.
The criteria may be a range of; Input voltage, CCD
Bus message, or coded messages to the SKIM. If all
of the criteria for monitoring a circuit or function
are met and a fault is sensed, a diagnostic trouble
code will be stored in the SKIM memory.
3.2.8 SKIS OPERATION
When ignition power is supplied to the SKIM, the
SKIM performs an internal self-test. After the self-
test is completed, the SKIM neergizes the antenna
(this activates the transponder chop responds to the
challenge by generating an encrypted response
message using the following:
Secret Key -This is an electronically stored
value (identification number) that is unique to each
SKIS. The secret key is stored in the SKIM, PCM
and all ignition key tranponders.
Challenge -This is a random numbr that is
generated by the SKIM at each ignition key cycle.
The secret key and challenge are plugged into an
algorithm that produces the encrypted response
message. The transponder uses the crypto algo-
rithm to receive, decode and respond to the message
sent by the SKIM. After responding to the coded
message, the transponder sends a transponder ID
message to the SKIM. The SKIM compares the
transponder ID to the available valid key codes in
the SKIM memory (8 key maximum). After validat-
ing the key the SKIM sends a CCD Bus message
called a ``Seed Request'' to the engine controller
then waits for a PCM response. If the PCM does not
respond, the SKIM will send the seed request agian.
After three failed attempts the SKIM will stop
sending the seed request and store a trouble code. If
the PCM sends a seed response, the SKIM sends a
valid/invalid key message to the PCM. This is an
encrypted message that is generated using the
following:
VIN -Vehicle Identification Number
Seed -This is a random number that is generated
by the PCM at each ignition key cycle.
The VIN and seed are plugged into a rolling code
algorithm that encrypts the ``valid/invalid key'' mes-
sage. The PCM uses the rolling code algorithm to
receive, decode and respond to the valid/invalid key
message sent by the SKIM. After sending the valid/
invalid key massage the SKIM waits 3.5 seconds for
a PCM status message from the PCM. If the PCM
does not respond with a valid key message to the
SKIM, a fault is detected and a trouble code is
stored.
The SKIS incorporates a warning lamp (``ALARM
SET'') located in the message center. The lamp
receives switched ignition voltage and is hardwired
to the body control module. The lamp is actuated
when the SKIM sends a CCD Bus message to thebody controller requesting the lamp on. The body
controller then provides the ground for the lamp.
The SKIM will request lamp operation for the
following:
- bulb checks at ignition on
- to alert the vehicle operator to a SKIS malfunc-
tion
For all faults except transponder faults and VIN
mismatch, the lamp remains on steady. In the event
of a tranponder fault the light flashes at a rate of 1
Hz (once per second). If a fault is pesent the lamp
will emain on or flashing for the complete ignition
cycle. If a fault is stored in SKIM memory which
prevents the system form operating properly, the
PCM will allow the engine to start and run (for 2
seconds) up to six times. After the sixth attempt, the
PCM disables the starter relay until the fault is
corrected.
3.2.9 PROGRAMMING THE POWERTRAIN
CONTROL MODULE
Important Note:Before replacing the PCM for a
failed driver, control circuit or ground circuit, be
sure to check the related component/circuit integ-
rity for failures not detected due to a double fault in
the circuit. Most PCM driver/control circuit failures
are caused by internal failure to components (i.e.
12-volt pull-ups, drivers and ground sensors). These
failures are difficult to detect when a double fault
has occurred and only one DTC has set.
NOTE:IF THE PCM AND THE SKIM ARE
REPLACED AT THE SAME TIME, PROGRAM
THE VIN INTO THE PCM FIRST. ALL VEHICLE
KEYS WILL THEN NEED TO BE REPLACED
AND PROGRAMMED TO THE NEW SKIM.
The SKIS ``Secret Key'' is an ID code that is
unique to each SKIS. This code is programmed and
stored in the SKIM, engine controller and transpon-
der ship (ignition key). When replacing the PCM it
is necessary to program the secret key into the
PCM.
1. Turn the ignition on (transmission in park/
neutral).
2. Use the DRB and select ``THEFT ALARM'',
SKIM then MISCELLANEOUS''.
3. Select ``PCM REPLACED''.
4. Enter secured access mode by entering the vehi-
cle four-digit PIN.
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NOTE:IF THREE ATTEMPTS ARE MADE TO
ENTER THE SECURE ACCESS MODE USING
AN INCORRECT PIN, SECURED ACCESS
MODE WILL BE LOCKED OUT FOR ONE
HOUR. TO EXIT THIS LOCKOUT MODE, TURN
THE IGNITION TO THE RUN POSITION FOR
ONE HOUR THEN ENTER THE CORRECT
PIN. (ENSURE ALL ACCESSORIES ARE
TURNED OFF. ALSO MONITOR THE
BATTERY STATE AND CONNECT A BATTERY
CHARGER IF NECESSARY).
5. Press ``ENTER'' to transfer the secret key (the
SKIM will send the secret key to the PCM).
3.2.10 PROGRAMMING THE SENTRY KEY
IMMOBILIZER MODULE
NOTE:IF THE PCM AND THE SKIM ARE
REPLACED AT THE SAME TIME, PROGRAM
THE VIN INTO THE PCM FIRST. ALL VEHICLE
KEYS WILL THEN NEED TO BE REPLACED
AND PROGRAMMMED TO THE NEW SKIM.
1. Turn the ignition on (transmission in park/
neutral).
2. Use the DRB and select ``THEFT ALARM'',
``SKIM'' then MISCELLLANEOUS.
3. Select ``SKIM MOSULE REPLACEMENT (GAS-
OLINE)''
4. Program the vehicle four-digit PIN into the
SKIM.
5. Select ``COUNTRY CODE'' and enter the correct
country.
NOTE:BE SURE TO ENTER THE CORRECT
COUNTRY CODE. IF THE INCORRECT
COUNTRY CODE IS PROGRAMMED INTO
SKIM, THE SKIM MUST BE REPLACED.
6. Select ``UPDATE VIN'' (the SKIM will learn the
VIN from the PCM).
7. Press ``ENTER'' to transfer the VIN (the PCM
will send the VIN to the SKIM).
8. The DRB will ask if you want to transfer the
secret key. Select ``ENTER'' to transfer secret key
from the PCM. This will ensure the current
vehicle ignition keys will still operate the SKIS
system.
3.2.11 PROGRAMMING THE IGNITION
KEYS TO THE SENTRY KEY
IMMOBILIZER MODULE
1. Turn the ignition on (transmission in park/
neutral).2. Use the DRB and select ``THEFT ALARM'',
``SKIM'' then ``MISCELLANEOUS''.
3. Select ``PROGRAM IGNITION KEYS''.
4. Enter secured access mode by entering the vehi-
cle four-digit PIN.
NOTE:A MAXIMUM OF EIGHT KEYS CAN BE
LEARNED TO EACH SKIM. ONCE A KEY IS
LEARNED TO A SKIM IT (THE KEY) CANNOT
BE RANFERRED TO ANOTHER VEHICLE.
If ignition key programming is unsuccessful, the
DRB will display one of the following messages:
Programming Not Attempted -The DRB at-
tempts to read the programmed key status and
there are no keys programmmed in the SKIM
memory.
Programming Key Failed -(Possible Used Key
From Wrong Vehicle) - SKIM is unable to program
key due to one of the following:
- faulty ignition key transponder
- ignition key is programmed to another vehicle.
8 Keys Already Learned, Programming Not
Done -SKIM transponder ID memory is full.
1. Obtain ignition keys to be programmed from
customer (8 keys maximum)
2. Using the DRB, erase all ignition keys by select-
ing ``MISCELLANEOUS'' and ``ERASE ALL
CURRENT IGN. KEYS''
3. Program all ignition keys.
Learned Key In Ignition -Ignition key tran-
sponder ID is currently programmed in SKIM mem-
ory.
3.3 DIAGNOSTIC TROUBLE CODES
Each diagnostic trouble code is diagnosed by
following a specific testing procedure. The diagnos-
tic test procedures contain step-by-step instructions
for determining the cause of trouble codes as well as
no trouble code problems. It is not necessary to
perform all of the tests in this book to diagnose an
individual code.
Always begin by reading the diagnostic trouble
codes using the DRBIIIt.
3.3.1 HARD CODE
A diagnostic trouble code that comes back within
one cycle of the ignition key is a ªhardº code. This
means that the defect is there every time the
powertrain control module checks that circuit or
function. Procedures in this manual verify if the
trouble code is a hard code at a the beginning of
each test. When it is not a hard code, an ªintermit-
tentº test must be performed.
Codes that are for Euro Stage III OBD monitors will
not set with just the ignition key on. Comparing these
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to non-emission codes, they will seem like an intermit-
tent. These codes require a set of parameters to be
performed (The DRBIIItpre-test screens will help
with this for MONITOR codes), this is called a ªTRIPº.
All EURO STAGE III OBD DTCs will be set after one
or in some cases two trip failures, and the MIL will be
turned on. These codes require three successful (no
failures) TRIPS to extinguish the MIL, followed by 40
warm-up cycles to erase the code.
3.3.2 INTERMITTENT CODE
A diagnostic trouble code that is not there every
time the PCM checks the circuit is an ªintermittentº
code. Most intermittent codes are caused by wiring
or connector problems. Defects that come and go
like this are the most difficult to diagnose; they
must be looked for under specific conditions that
cause them. The following checks may assist you in
identifying a possible intermittent problem:
²Visually inspect related wire harness connectors.
Look for broken, bent, pushed out, or corroded
terminals.
²Visually inspect the related harnesses. Look for
chafed, pierced, or partially broken wire.
²Refer to any Hotline Newsletters or technical
service bulletins that may apply.
²Use the DRBIIItdata recorder or co-pilot.
²Use the DRBIIItPEP module lab scope.
3.3.3 RESET COUNTER
The reset counter counts the number of times the
vehicle has been started since codes were last set,
erased, or the battery was disconnected. The reset
counter will count up to 255 start counts.
The number of starts helps determine when the
trouble code actually happened. This is recorded by
the PCM and can be viewed on the DRBIIItas
STARTS since set.
When there are no trouble codes stored in mem-
ory, the DRBIIItwill display ªNO DTC'S Detectedº
and the reset counter will show ªSTARTS since
clear = XXX.º
3.3.4 HANDLING NO TROUBLE CODE
PROBLEMS
Symptom checks cannot be used properly unless
the driveability problem characteristic actually
happens while the vehicle is being tested.
Select the symptom that most accurately de-
scribes the vehicle's driveability problem and then
perform the test routine that pertains to this symp-
tom. Perform each routine test in sequence until the
problem is found. For definitions, see Section 6.0
Glossary of Terms.SYMPTOM DIAGNOSTIC TEST
HARD START CHECKING THE 5-VOLT
SUPPLY CIRCUIT
CHECKING SECONDARY
IGNITION SYSTEM
CHECKING ENGINE VAC-
UUM
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING ENGINE ME-
CHANICAL SYSTEMS
CHECKING EVAP EMISSION
SYSTEM
CHECKING EGR SYSTEM
CHECKING IAT SENSOR
START AND
STALLCHECKING THE 5-VOLT
SUPPLY CIRCUIT
CHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
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CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
HESITATION/
SAG/
STUMBLECHECKING THE 5-VOLT
SUPPLY CIRCUIT
CHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING ENGINE VAC-
UUM
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING O2S HEATER
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING ENGINE ME-
CHANICAL SYSTEMS
CHECKING EVAP EMISSION
SYSTEM
CHECKING EGR SYSTEM
CHECKING IAT SENSOR
CHECKING PNP SWITCH
SURGE CHECKING THE 5-VOLT
SUPPLY CIRCUIT
CHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATIONCHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING EVAP EMISSION
SYSTEM
LACK OF
POWER/
SLUGGISHCHECKING THE 5-VOLT
SUPPLY CIRCUIT
CHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING EGR SYSTEM
SPARK
KNOCK/
DETONATIONCHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
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CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING EVAP EMISSION
SYSTEM
CUTS OUT/
MISSESCHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING THE FUEL
PRESSURE
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING EGR SYSTEM
BACKFIRE/
POPBACKCHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING THE FUEL
PRESSURE
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING EGR SYSTEM
RUNS
ROUGH/
UNSTABLE/
ERRATIC
IDLECHECKING SECONDARY
IGNITION SYSTEMCHECKING PCM POWER
AND GND CKT
CHECKING ENGINE VAC-
UUM
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
CHECKING FOR OXYGEN
SENSOR SWITCHING
CHECKING O2S HEATER
CHECKING IDLE AIR CON-
TROL MOTOR OPERATION
CHECKING ENGINE ME-
CHANICAL SYSTEMS
CHECKING EVAP EMISSION
SYSTEM
CHECKING EGR SYSTEM
CHECKING IAT SENSOR
CHECKING PNP SWITCH
POOR FUEL
ECONOMYCHECKING SECONDARY
IGNITION SYSTEM
CHECKING PCM POWER
AND GND CKT
CHECKING ENGING VAC-
UUM
CHECKING THE FUEL
PRESSURE
CHECKING COOLANT SEN-
SOR CALIBRATION
CHECKING THROTTLE PO-
SITION SENSOR CALIBRA-
TION
CHECKING MAP SENSOR
CALIBRATION
CHECKING THE MINIMUM
IDLE AIR FLOW
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