1991 FORD FESTIVA air condition

gases into harmless substances.
PCV VALVE
The Positive Crankcase Ventilation (PCV) valve, located in the valve cover, controls the flow of blow-by gas from the crankcase to the intake
man ifo l d .
SELF-DIAGNOSTIC SYSTEM
The ECA monitors its inputs and outputs. When it detects a malfunction, it sets a code in the ECA and sends a signal to the CHECK ENGINE
warning light. The light remains on until the malfunction is repaired. Trouble codes may be accessed at the Self-Test Output (STO) and Self-
Test Input (STI) connectors, near the battery.
If a sensor fails, the ECA will use a substitute value in its calculations to permit continued engine operation. In this condition, the vehicle will
run, but driveability may be poor. Intermittent failures may result in the CHECK ENGINE warning light flickering or going out after the fault
goes away. The corresponding trouble code, however, will be stored in the ECA. If fault does not recur, the related code will be erased from
ECA memory.
CHECK ENGINE LIGHT
Hard failures cause the CHECK ENGINE warning light to come on and remain on until the malfunction is repaired. If the warning light comes
on and stays on during vehicle operation, determine and correct the cause of the malfunction. NOTE:For additional inform ation and operating procedures for the self-diagnostic system , refer to T EST S
W/CODES article in the ENGINE PERFORMANCE Section.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00022697
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GENERAL INFORMATION
Com m only Used Abbreviations
* PLEASE READ THIS FIRST *
"A"
A
Amperes
ABS
Anti-Lock Brakes
ABRS
Air Bag Restraint System
AC
Alternating Current
A/C
Air Conditioning
ACCS
A/C Cycling Switch
ACCUM
Accumulator
ACCY
Accessory
ACT
Air Charge Temperature Sensor
ADJ
Adjust or Adjustable
ADV
Advance
AFS
Airflow Sensor
AI
Air Injection
AIR or A.I.R.
Air Injection Reactor
AIS
Air Injection System
Alt.
Alternator or Altitude
Amp./amp/amps
Ampere NOTE:T his article is intended for general inform ation purposes only. T his inform ation m ay not apply to all
m akes and m odels. Not all abbreviations are covered as m anufacturers add new ones every day.
Page 1 of 15 MITCHELL 1 ARTICLE - GENERAL INFORMATION Commonly Used Abbreviations
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GENERAL INFORMATION
T rouble Shooting - Basic Procedures
* PLEASE READ THIS FIRST *
ACCESSORIES & ELECTRICAL
CHARGING SYSTEM TROUBLE SHOOTING
BASIC CHARGING SYSTEM TROUBLE SHOOTING CHART NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Vehicle Will Not Start
Dead batteryCheck battery cells, alternator
belt tension and alternator
output
Loose or corroded battery connectionsCheck all charging system
connections
Ignition circuit or switch malfunctionCheck and replace as necessary
Alternator Light Stays On With Engine Running
Loose or worn alternator drive beltCheck alternator drive tension
and condition, See Belt
Adjustment in TUNE-UP article
in the TUNE-UP section
Loose alternator wiring connectionsCheck all charging system
connections
Short in alternator light wiringSee Indicator Warning Lights in
STANDARD INSTRUMENTS
in the ACCESSORIES &
EQUIPMENT section
Defective alternator stator or diodesSee Bench Tests in
ALTERNATOR article
Defective regulatorSee Regulator Check in
ALTERNATOR article
Alternator Light Stays Off With Ignition Switch ON
Blown fuseSee WIRING DIAGRAMS
Defective alternatorSee Testing in ALTERNATOR
article
Defective indicator light bulb or socketSee Indicator Warning Lights in
STANDARD INSTRUMENTS
in the ACCESSORIES &
EQUIPMENT section
Alternator Light Stays OFF With Ignition Switch ON
Short in alternator wiringSee On-Vehicle Tests in
ALTERNATOR article
Defective rectifier bridgeSee Bench Tests in
ALTERNATOR article
Lights or Fuses Burn Out Frequently
Defective alternator wiringSee On-Vehicle Tests in
ALTERNATOR article
Defective regulatorSee Regulator Check in
ALTERNATOR article
Defective batteryCheck and replace as necessary
Ammeter Gauge Shows Discharge
Loose or worn drive beltCheck alternator drive belt
tension and condition. See Belt
Adjustment in TUNE-UP article
in the TUNE-UP section
Defective wiringCheck all wires and wire
Page 1 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
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IGNITION SYSTEM TROUBLE SHOOTING
connections
Defective alternator or regulatorSee Bench Tests and On-
Vehicle Tests in
ALTERNATOR article
Defective ammeter, or improper ammeter wiring connectionSee Testing in STANDARD
INSTRUMENTS in the
ACCESSORIES &
EQUIPMENT section
Noisy Alternator
Loose drive pulleyTighten drive pulley attaching
nut
Loose mounting boltsTighten all alternator mounting
bolts
Worn or dirty bearingsSee Bearing Replacement
ALTERNATOR article
Defective diodes or statorSee Bench Test in
ALTERNATOR article
Battery Does Stay Charged
Loose or worn drive beltCheck alternator drive belt
tension and condition. See Belt
Adjustment in appropriate
TUNE-UP article in the TUNE-
UP section
Loose or corroded battery connectionsCheck all charging system
connections
Loose alternator connectionsCheck all charging system
connections
Defective alternator or batterySee On-Vehicle Tests and
Bench Tests in ALTERNATOR
article
Add-on electrical accessories exceeding alternator capacityInstall larger alternator
Battery Overcharged-Uses Too Much Water
Defective batteryCheck alternator output and
repair as necessary
Defective alternatorSee On-Vehicle Test and Bench
Tests in ALTERNATOR article
Excessive alternator voltageCheck alternator output and
repair as necessary
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
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Fig. 2: Ignition Primary Trouble Shooting Chart

STARTER TROUBLE SHOOTING
BASIC STARTER TROUBLE SHOOTING CHART
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Starter Fails to Operate
Dead battery or bad connections between starter and batteryCheck battery charge and all
wires and connections to
starter
Ignition switch faulty or misadjustedAdjust or replace ignition
switch
Open circuit between starter switch ignition terminal on starter relayCheck and repair wires and
connections as necessary
Starter relay or starter defectiveSee Testing in STARTER
article
Open solenoid pull-in wireTesting in STARTER article
Starter Does Not Operate and Headlights Dim
Weak battery or dead cellCharge or replace battery as
necessary
Loose or corroded battery connectionsCheck that battery connections
are clean and tight
Internal ground in starter windingsSee Testing in STARTER
article
Grounded starter fieldsSee Testing in STARTERS
Armature rubbing on poleSee STARTER article shoes
Starter Turns but Engine Does Not Rotate
Starter clutch slippingSee STARTER article
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AIR CONDITIONING & HEAT
AIR CONDITIONING TROUBLE SHOOTING
BASIC AIR CONDITIONING TROUBLE SHOOTING CHART
HEATER SYSTEM TROUBLE SHOOTING
BASIC HEATER SYSTEM TROUBLE SHOOTING CHART
Broken lead or loose soldered connectionsRepair wire or wire
connections as necessary
Solenoid Plunger Vibrates When Switch is Engaged
Weak batteryCharge or replace battery as
necessary
Solenoid contacts corrodedClean contacts or replace
solenoid
Faulty wiringCheck all wiring leading to
solenoid
Broken connections inside switch coverRepair connections or replace
solenoid
Open hold-in wiresolenoid
Low Current Draw
Worn brushes or weak brush springsReplace brushes or brush
springs as necessary
High Pitched Whine During Cranking Before Engine Fires but Engine Fires and Cranks Normally
Distance too great between starter pinion and flywheelAlign starter or check that
correct starter and flywheel are
being used
High Pitched Whine After Engine Fires With Key released. Engine Fires and Cranks Normally
Distance too small between starter pinion and flywheelFlywheel runout contributes to
the intermittent nature
WARNING:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITIONPOSSIBLE CAUSE
Compressor Not WorkingCompressor clutch circuit open.
.....Compressor clutch coil inoperative.
.....Poor clutch ground connection.
.....Fan belts loose.
.....Thermostatic switch inoperative.
.....Thermostatic switch not adjusted.
.....Ambient temperature switch open.
.....Superheat fuse blown.
Excessive Noise or VibrationMissing or loose mounting bolts.
.....Bad idler pulley bearings.
.....Fan belts not tightened correctly.
.....Compressor clutch contacting body.
.....Excessive system pressure.
.....Compressor oil level low.
.....Damaged clutch bearings.
.....Damaged reed valves.
.....Damaged compressor.
In su fficien t o r No Co o l in g; Co mp resso r
WorkingExpansion valve inoperative.
.....Heater control valve stuck open.
.....Low system pressure.
.....Blocked condenser fins.
.....Blocked evaporator fins.
.....Vacuum system leak.
.....Vacuum motors inoperative.
.....Control cables improperly adjusted.
.....Restricted air inlet.
.....Mode doors binding.
.....Blower motor inoperative.
.....Temperature above system capacity.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to DIAGNOST IC,
or T EST ING articles available in the section(s) you are accessing.
Page 6 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
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BRAKES
BRAKE SYSTEM TROUBLE SHOOTING
BRAKE SYSTEM TROUBLE SHOOTING CHART
CONDITIONPOSSIBLE CAUSE
Insufficient, Erratic, or No HeatLow Coolant Level
.....Incorrect thermostat.
.....Restricted coolant flow through core.
.....Heater hoses plugged.
.....Misadjusted control cable.
.....Sticking heater control valve.
.....Vacuum hose leaking.
.....Vacuum hose blocked.
.....Vacuum motors inoperative.
.....Blocked air inlet.
.....Inoperative heater blower motor.
.....Oil residue on heater core fins.
.....Dirt on heater core fins.
Too Much HeatImproperly adjusted cables.
.....Sticking heater control valve.
.....No vacuum to heater control valve.
.....Temperature door stuck open.
Air Flow Changes During AccelerationVacuum system leak.
.....Bad check valve or reservoir.
Air From Defroster At All TimesVacuum system leak.
.....Improperly adjusted control cables.
.....Inoperative vacuum motor.
Blower Does Not Operate CorrectlyBlown fuse.
.....Blower motor windings open.
.....Resistors burned out.
.....Motor ground connection loose.
.....Wiring harness connections loose.
.....Blower motor switch inoperative.
.....Blower relay inoperative.
.....Fan binding or foreign object in housing.
.....Fan blades broken or bent.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Brakes Pull Left or Right
Incorrect tire pressureInflate tires to proper pressure
Front end out of alignmentSee WHEEL ALIGNMENT
Mismatched tiresCheck tires sizes
Restricted brake lines or hosesCheck hose routing
Loose or malfunctioning caliperSee DISC BRAKES or
BRAKE SYSTEM
Bent shoe or oily liningsSee DRUM BRAKES or
BRAKE SYSTEM
Malfunctioning rear brakesSee DRUM, DISC BRAKES
or BRAKE SYSTEM
Loose suspension partsSee SUSPENSION
Noises Without Brakes Applied
Front linings worn outReplace linings
Dust or oil on drums or rotorsSee DRUM, DISC BRAKES
or BRAKE SYSTEM
Noises With Brakes Applied
Insulator on outboard shoe damagedSee DISC BRAKES or
BRAKE SYSTEM
Incorrect pads or liningsReplace pads or linings
Brake Rough, Chatters or Pulsates
Excessive lateral runoutCheck rotor runout
Parallelism not to specificationsReface or replace rotor
Wheel bearings not adjustedSee SUSPENSION
Rear drums out-of-roundReface or replace drums
Disc pad reversed, steel against rotorRemove and reinstall pad
Excessive Pedal Effort
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ENGINE MECHANICAL
COOLING SYSTEM TROUBLE SHOOTING
COOLING SYSTEM TROUBLE SHOOTING
Malfunctioning power unitSee POWER BRAKES or
BRAKE SYSTEM
Partial system failureCheck fluid and pipes
Worn disc pad or liningReplace pad or lining
Caliper piston stuck or sluggishSee DISC BRAKES or
BRAKE SYSTEM
Master cylinder piston stuckSee MASTER CYLINDERS
or BRAKE SYSTEM
Brake fade due to incorrect pads for liningsReplace pads or linings
Linings or pads glazedReplace pads or linings
Worn drumsReface or replace drums
Excessive Pedal Travel
Partial brake system failureCheck fluid and pipes
Insufficient fluid in master cylinderSee MASTER CYLINDERS
or BRAKE SYSTEM
Air trapped in systemSee BRAKE BLEEDING or
BRAKE SYSTEM
Rear brakes not adjustedSee Adjustments in DRUM
BRAKES or BRAKE
SYSTEM
Bent shoe or liningSee DRUM BRAKES or
BRAKE SYSTEM
Plugged master cylinder capSee MASTER CYLINDERS
or BRAKE SYSTEM
Improper brake fluidReplace brake fluid
Pedal Travel Decreasing
Compensating port pluggedSee MASTER CYLINDERS
or BRAKE SYSTEM
Swollen cup in master cylinderSee MASTER CYLINDERS
or BRAKE SYSTEM
Master cylinder piston not returningSee MASTER CYLINDERS
or BRAKE SYSTEM
Weak shoe retracting springsSee DRUM BRAKES BRAKE
SYSTEM
Wheel cylinder piston stickingSee DRUM BRAKES or
BRAKE SYSTEM
Dragging Brakes
Master cylinder pistons not returningSee MASTER CYLINDERS
BRAKE SYSTEM
Restricted brake lines or hosesCheck line routing
Incorrect parking brake adjustmentSee DRUM BRAKES BRAKE
SYSTEM
Parking Brake cables frozenSee DRUM BRAKES BRAKE
SYSTEM
Incorrect installation of inboard disc padRemove and replace correctly
Power booster output rod too longSee POWER BRAKE UNITS
BRAKE SYSTEM
Brake pedal not returning freelySee DISC, DRUM BRAKES
BRAKE SYSTEM
Brakes Grab or Uneven Braking Action
Malfunction of combination valveSee CONTROL VALVE or
BRAKE SYSTEM
Malfunction of power brake unitSee POWER BRAKE UNITS
or BRAKE SYSTEM
Binding brake pedalSee DISC, DRUM BRAKES
or BRAKE SYSTEM
Pulsation or Roughness
Uneven pad wear caused by caliperSee DISC BRAKES or
BRAKE SYSTEM
Uneven rotor wearSee DISC BRAKES or
BRAKE SYSTEM
Drums out-of-roundReface or replace drums
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Page 8 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
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