Repair and Diagnosis
- A L L Diagnostic Trouble Codes ( DTC )
- Relays and Modules
- Relays and Modules - Cooling System
- Relays and Modules - Cruise Control
- Relays and Modules - HVAC
- Relays and Modules - Lighting and Horns
- Relays and Modules - Power and Ground Distribution
- Relays and Modules - Powertrain Management
- Relays and Modules - Wiper and Washer Systems
- Sensors and Switches
- Sensors and Switches - Body and Frame
- Sensors and Switches - Brakes and Traction Control
- Sensors and Switches - Cooling System
- Sensors and Switches - Cruise Control
- Sensors and Switches - Engine
- Sensors and Switches - HVAC
- Sensors and Switches - Instrument Panel
- Sensors and Switches - Lighting and Horns
- Sensors and Switches - Powertrain Management
- Sensors and Switches - Computers and Control Systems
- Air Flow Meter/Sensor
- Barometric Pressure Sensor
- Camshaft Position Sensor
- Coolant Temperature Sensor/Switch (For Computer)
- Crankshaft Position Sensor
- EGR Valve Position Sensor
- Air Temperature Sensor ( Ambient / Intake )
- Manifold Pressure/Vacuum Sensor
- Oxygen Sensor
- Power Steering Pressure Switch
- Throttle Position Sensor
- Transmission Position Sensor/Switch
- Vehicle Speed Sensor
- Sensors and Switches - Emission Control Systems
- Sensors and Switches - Fuel Delivery and Air Induction
- Sensors and Switches - Ignition System
- Sensors and Switches - Computers and Control Systems
- Sensors and Switches - Restraints and Safety Systems
- Sensors and Switches - Starting and Charging
- Sensors and Switches - Steering and Suspension
- Sensors and Switches - Transmission and Drivetrain
- Sensors and Switches - Wiper and Washer Systems
- Maintenance
- Alignment
- Tune-up and Engine Performance Checks
- Timing Belt
- Timing Component Alignment Marks
- Drive Belt
- Filters
- Hoses
- Fluids
- Brake Bleeding
- Fuses and Circuit Breakers
- Service Reminder Indicators
- Wheels and Tires
- Service Intervals
- Severe Service Defined
- Routine Service
- Normal Service
- 7500 MI or 12000 KM
- 15000 MI or 24000 KM
- 22500 MI or 36000 KM
- 30000 MI or 48000 KM
- 37500 MI or 60000 KM
- 45000 MI or 72000 KM
- 52500 MI or 84000 KM
- 60000 MI or 96000 KM
- 67500 MI or 108000 KM
- 75000 MI or 120000 KM
- 82500 MI or 132000 KM
- 90000 MI or 144000 KM
- 97500 MI or 156000 KM
- 105000 MI or 168000 KM
- 112500 MI or 180000 KM
- 120000 MI or 192000 KM
- 150000 MI or 240000 KM
- Severe Service
- 3000 MI or 4800 KM
- 6000 MI or 9600 KM
- 9000 MI or 14400 KM
- 12000 MI or 19200 KM
- 15000 MI or 24000 KM
- 18000 MI or 28800 KM
- 21000 MI or 33600 KM
- 24000 MI or 38400 KM
- 27000 MI or 43200 KM
- 30000 MI or 48000 KM
- 33000 MI or 52800 KM
- 36000 MI or 57600 KM
- 39000 MI or 62400 KM
- 42000 MI or 67200 KM
- 45000 MI or 72000 KM
- 48000 MI or 76800 KM
- 51000 MI or 81600 KM
- 54000 MI or 86400 KM
- 57000 MI or 91200 KM
- 60000 MI or 96000 KM
- 63000 MI or 100800 KM
- 66000 MI or 105600 KM
- 69000 MI or 110400 KM
- 72000 MI or 115200 KM
- 75000 MI or 120000 KM
- 78000 MI or 124800 KM
- 81000 MI or 129600 KM
- 84000 MI or 134400 KM
- 87000 MI or 139200 KM
- 90000 MI or 144000 KM
- 93000 MI or 148800 KM
- 96000 MI or 153600 KM
- 99000 MI or 158400 KM
- 102000 MI or 163200 KM
- 105000 MI or 168000 KM
- 108000 MI or 172800 KM
- 111000 MI or 177600 KM
- 114000 MI or 182400 KM
- 117000 MI or 187200 KM
- 120000 MI or 192000 KM
- 150000 MI or 240000 KM
Service and Repair
Technical Service Bulletins
- Engine, Cooling and Exhaust
- Engine
- Camshaft, Lifters and Push Rods
- Cylinder Block Assembly
- Cylinder Head Assembly
- Drive Belts, Mounts, Brackets and Accessories
- Engine Lubrication
- Intake Manifold
- Lamps and Indicators - Engine
- Seals and Gaskets
- Sensors and Switches - Engine
- Timing Components
- Tune-up and Engine Performance Checks
- Water Pump
- Application and ID
- Service and Repair
Specifications- Technical Service Bulletins
- Cooling System
- Coolant
- Radiator Cooling Fan
- Engine - Coolant Temperature Sensor/Switch
- Heater Core
- Lamps and Indicators - Cooling System
- Relays and Modules - Cooling System
- Sensors and Switches - Cooling System
- Temperature Gauge
- Temperature Warning Lamp/Indicator
- Thermostat
- Water Pump
Testing and Inspection- Service and Repair
Diagrams- Specifications
- Technical Service Bulletins
- Exhaust System
- Engine
- Powertrain Management
- Relays and Modules - Powertrain Management
- Sensors and Switches - Powertrain Management
- Sensors and Switches - Computers and Control Systems
- Air Flow Meter/Sensor
- Barometric Pressure Sensor
- Camshaft Position Sensor
- Coolant Temperature Sensor/Switch (For Computer)
- Crankshaft Position Sensor
- EGR Valve Position Sensor
- Air Temperature Sensor ( Ambient / Intake )
- Manifold Pressure/Vacuum Sensor
- Oxygen Sensor
- Power Steering Pressure Switch
- Throttle Position Sensor
- Transmission Position Sensor/Switch
- Vehicle Speed Sensor
- Sensors and Switches - Emission Control Systems
- Sensors and Switches - Fuel Delivery and Air Induction
- Sensors and Switches - Ignition System
- Sensors and Switches - Computers and Control Systems
- Tune-up and Engine Performance Checks
- Computers and Control Systems
- Air Flow Meter/Sensor
- Air Temperature Sensor ( Ambient / Intake )
- Barometric Pressure Sensor
- Camshaft Position Sensor
- Coolant Temperature Sensor/Switch (For Computer)
- Crankshaft Position Sensor
- Data Link Connector
- Diagnostic Mode Switch/Connector
- EGR Valve Position Sensor
- Engine Control Module
- Idle Speed/Throttle Actuator - Electronic
- Idle Up Control Valve
- Idle/Throttle Speed Control Unit
- Main Relay (Computer/Fuel System)
- Malfunction Indicator Lamp
- Manifold Pressure/Vacuum Sensor
- Oxygen Sensor
- Power Steering Pressure Switch
- Relays and Modules - Computers and Control Systems
- Sensors and Switches - Computers and Control Systems
- Air Flow Meter/Sensor
- Barometric Pressure Sensor
- Camshaft Position Sensor
- Coolant Temperature Sensor/Switch (For Computer)
- Crankshaft Position Sensor
- EGR Valve Position Sensor
- Air Temperature Sensor ( Ambient / Intake )
- Manifold Pressure/Vacuum Sensor
- Oxygen Sensor
- Power Steering Pressure Switch
- Throttle Position Sensor
- Transmission Position Sensor/Switch
- Vehicle Speed Sensor
- Throttle Position Sensor
- Transmission Position Sensor/Switch
- Vehicle Speed Sensor
Service Precautions
Description and Operation- Testing and Inspection
- Initial Inspection and Diagnostic Overview
- Reading and Clearing Diagnostic Trouble Codes
- Performance Diagnostic Overview (Quick Test)
- Performance Diagnostic Procedures (Quick Test)
- 1.0 - Visual Check & Vehicle Preparation
- 2.0 - Equipment Hook-Up
- 3.0A - Key on Engine Off Self Test
- 3.0B - Key-on, Engine-Off Self-Test (Codes)
- 4.0A - Engine Running Self-Test
- 4.0B - Service Code Chart
- 5.0A - Continuous Self-Test
- 5.0B - Continuous Self-Test
- 5.0C - Service Code Chart
- 6.0 - Switch Monitor Test
- Diagnostic Trouble Code Tests and Associated Procedures
- Symptom Related Diagnostic Procedures
- 1 - Backfires
- 2 - Diesels (Run-On)
- 3 - Lacks Power
- 4 - Spark Knock (Pinging)
- 5 - Stalls/Quits
- 6 - Stumbles/Hesitates During Acceleration
- 7 - Misses/Surges
- 8 - Idles Too Fast/Slow Return to Idle
- 9 - Idles Rough
- 10 - Engine Speed Up
- 11 - Cranks Normally But Won't Start
- 12 - Cranks Normally But Slow to Start
- 13 - Poor Fuel Economy
- 14 - Overheats
- 15 - Exhaust Odor/Smoke
- 16 - Excessive Oil Use
- 17 - Fuel Odor/Leaks
- 18 - Fails Emission Test
- 19 - Unusual Noises
- 20 - "Check Engine" MIL Light Always/Never On
- Pinpoint Tests
- Pinpoint Test Instructions
- Pinpoint Tests
- A - No Start (Ignition Pulse)
- B - Vehicle Battery
- DA - Vane Air Temperature EFI
- DE - Engine Coolant Temperature Sensor (ECT)
- DF - Barometric Pressure Sensor
- DH - Throttle Position (TP) Sensor
- DK - Vane Air Flow Sensor (VAF)
- FA - Neutral Gear Switch and Clutch Engage Switch
- FB - Inhibitor Switch
- FC - Vehicle (Key) Power
- FD - Brake On/Off (BOO)
- FF - Air Conditioning Presure Switch
- FG - Electrical Load Unit (ELU)
- HA - Fuel Control
- HE - EGO Sensor Feedback
- KD - Canister Purge (CANP)
- KE - Idle Speed Control
- KV - Pressure Regulator Control (PRC)
- KW - Canister Purge Regulator
- ML - "Check Engine" Lamp (Malfunction Indicator Lamp)
- NB - Code "88" Continuously Flashing
- Q - No Codes/Codes Not Listed
- Scan Tool Testing and Procedures
- Diagrams
- Specifications
- Technical Service Bulletins
Tools and Equipment
- Emission Control Systems
- Air Injection
- Catalytic Converter
- Deceleration Valve
- Evaporative Emissions System
- Exhaust Gas Recirculation
- Positive Crankcase Ventilation
- Sensors and Switches - Emission Control Systems
- Service Precautions
- Application and ID
- Description and Operation
- Testing and Inspection
Adjustments
Locations- Diagrams
- Specifications
- Technical Service Bulletins
- Fuel Delivery and Air Induction
- Fuel Pressure
- Fuel Pressure Release
- Idle Speed
- Air/Fuel Mixture
- Air Flow Meter/Sensor
- Carburetor
- Dashpot
- Fuel
- Fuel Filter
- Fuel Injector
- Fuel Pressure Regulator
- Fuel Pump
- Fuel Shut-off Solenoid
- Fuel Tank
- Idle Speed/Throttle Actuator - Electronic
- Idle Up Control Valve
- Idle/Throttle Speed Control Unit
- Inertia Fuel Shutoff Switch
- Main Relay (Computer/Fuel System)
- Relays and Modules - Fuel Delivery and Air Induction
- Sensors and Switches - Fuel Delivery and Air Induction
- Throttle Position Sensor
- Service Precautions
- Description and Operation
- Testing and Inspection
- Pinpoint Tests
- ACDS - Air Cleaner & Duct System
- ACDS 1 - System Integrity Check
- ACDS 2 - Air Filter Inspection
- ACDS 3 - Vane Air Flow Meter Inspection
- ACDS 4 - Throttle Body Inspection
- ACDS 5 - Adjustment Check
- ACDS 6A - Idle Speed Adjustment Check (Before 11/2/87)
- ACDS 6B - Idle Speed Adjustment Check (After 11/2/87)
- ACDS 7 - BAC Valve Check
- ACDS 8 - BAC Valve Function Check
- ACDS 9 - Air Bypass Valve Check
- ACDS 10 - Air Bypass Valve Check
- ACDS 11 - Air Bypass Valve Check
- ACDS 12 - Air Bypass Valve Check
- ACDS 13 - Dashpot Check
- Fuel Delivery Diagnosis
- FDS 1 - Fuel Injection Integrity Check
- FDS 2 - Fuel Pump Pressure Test
- FDS 3 - Fuel Pressure Regulator Operation Test
- FDS 4 - Fuel Return Line Blockage Test
- FDS 5 - Fuel Injector Operation Test
- FDS 6 - Filter Inspection
- FDS 7 - In Tank Filter Inspection
- FDS 8 - Injector Flow Test
- FDS 9 - Fuel Pump Output Test
- FDS 10 - Fuel Pump Power Check
- FDS 11 - Check For Ground
- FDS 12 - Check For Short
- FDS 13 - Power Supply Check
- FDS 14 - Inertia Switch Continuity Check
- FDS 15 - Power Supply Check
- FDS 16 - Fuel Pump Relay Power Supply Check
- FDS 17 - Fuel Pump Relay Function Check
- FDS 18 - Fuel Pump Relay Operation Test
- FDS 19 - Ground Circuit Check
- FDS 20 - VAF Switch Check
- FDS 21 - VAF Circuit Inspection
- FDS 22 - Injector Resistance Test
- FDS 23 - Solenoid Resistor Test
- FDS 24 - Circuit Test
- FDS 25 - Circuit Test
- Idle - Idle-Up System
- Idle 1 - Visual Check
- Idle 2 - Electrical Load Solenoid Test
- Idle 3 - E/L Wiring Inspection
- Idle 4 - E/L Wiring Inspection
- Idle 5 - A/C Solenoid Check
- Idle 6 - A/C Wiring Inspection
- Idle 7 - A/C Wiring Inspection
- Idle 8 - A/C Wiring Inspection
- Idle 9 - Power Steering Switch Check
- Idle 10 - Power Steering Solenoid Test
- Idle 11 - P/S Wiring Inspection
- Idle 12 - P/S Wiring Inspection
- Idle 13 - P/S Wiring Inspection
- Idle 14 - Ground Check
- Idle 15 - Idle-Up Control Module Check
- Idle 16 - Idle-Up Control Module Check
- Idle 17 - Idle-Up Control Module Check
- Idle 18 - Idle-Up Control Module Check
- ACDS - Air Cleaner & Duct System
- Component Tests and General Diagnostics
- 1 - Backfires (Induction or Exhaust)
- 2 - Diesels (Run-On)
- 3 - Lacks Power
- 4 - Spark Knock (Pinging)
- 5 - Stalls/Quits
- 6 - Stumbles/Hesitates During Acceleration
- 7 - Misses/Surges
- 8 - Idles Too Fast/Slow Return to Idle
- 9 - Idles Rough
- 10 - Engine Speed Up
- 11 - Cranks Normally But Will Not Start
- 12 - Cranks Normally But Slow to Start
- 13 - Poor Fuel Economy
- 14 - Overheats
- 15 - Exhaust Odor/Smoke
- 16 - Excessive Oil Use
- 17 - Fuel Odor/Leaks
- 18 - Emission Test Failure
- 19 - Unusual Noises
- 20 - "Check Engine" MIL Light Always/Never On
- Pinpoint Tests
- Diagrams
- Technical Service Bulletins
- Ignition System
- Firing Order
- Ignition Timing
- Camshaft Position Sensor
- Crankshaft Position Sensor
- Distributor
- Ignition Cable
- Ignition Coil
- Ignition Control Module
- Ignition Relay
- Pick-Up Coil
- Relays and Modules - Ignition System
- Sensors and Switches - Ignition System
- Spark Plug
- Service Precautions
- Application and ID
- Description and Operation
- Testing and Inspection
- Flow of Diagnosis
- Symptom Related Diagnostic Procedures
- 1 - Backfires
- 2 - Diesels
- 3 - Lacks Power
- 4 - Spark Knock (Pinging)
- 5 - Stalls/Quits
- 6 - Stumbles/Hesitates During Acceleration
- 7 - Misses/Surges
- 8 - Idles Too Fast/Slow Return to Idle
- 9 - Idles Rough
- 10 - Engine Speed Up
- 11 - Cranks Normally But Won't Start
- 12 - Cranks Normally But Slow to Start
- 13 - Poor Fuel Economy
- 14 - Overheats
- 15 - Exhaust Odor/Smoke
- 16 - Excessive Oil Use
- 17 - Fuel Odor/Leaks
- 18 - Fails Emission Test
- 19 - Unusual Noises
- 20 - "Check Engine" MIL Light Always/Never On
- Component Tests and General Diagnostics
- Oscilloscope Patterns and Waveforms
- Service and Repair
- Diagrams
- Technical Service Bulletins
- Transmission Control Systems
- Sensors and Switches - Transmission and Drivetrain
- Testing and Inspection
- Test Description and Procedure
- Quick Test 1.0 - Visual Inspection
- Quick Test 2.0 - Equipment Hookup (Analog Volt/Ohm Meter)
- Quick Test 2.0 - Equipment Hookup (MIL Equipped Vehicles)
- Quick Test 2.0 - Equipment Hookup (Non-MIL Equipped Vehicles)
- Quick Test 3.0A - Key On Engine Off Self-Test
- Quick Test 3.0B - Service Code Chart
- Quick Test 4.0A - Engine Running Self-Test
- Quick Test 4.0B - Service Code Chart
- Quick Test 5.0A - Continuous Self-Test
- Quick Test 5.0B - Continuous Self-Test
- Quick Test 5.0C - Continuous Self-Test
- Quick Test 6.0 - Switch Monitor Test
- Application and ID
- Diagrams
- Technical Service Bulletins
- Transmission and Drivetrain
- Automatic Transmission/Transaxle
- Clutch
- Differential Assembly
- Drive Axles, Bearings and Joints
- Flex Plate
- Flywheel
- Manual Transmission/Transaxle
- Sensors and Switches - Transmission and Drivetrain
- Transmission Control Systems
- Sensors and Switches - Transmission and Drivetrain
- Testing and Inspection
- Test Description and Procedure
- Quick Test 1.0 - Visual Inspection
- Quick Test 2.0 - Equipment Hookup (Analog Volt/Ohm Meter)
- Quick Test 2.0 - Equipment Hookup (MIL Equipped Vehicles)
- Quick Test 2.0 - Equipment Hookup (Non-MIL Equipped Vehicles)
- Quick Test 3.0A - Key On Engine Off Self-Test
- Quick Test 3.0B - Service Code Chart
- Quick Test 4.0A - Engine Running Self-Test
- Quick Test 4.0B - Service Code Chart
- Quick Test 5.0A - Continuous Self-Test
- Quick Test 5.0B - Continuous Self-Test
- Quick Test 5.0C - Continuous Self-Test
- Quick Test 6.0 - Switch Monitor Test
- Testing and Inspection
- Technical Service Bulletins
- Tools and Equipment
- Brakes and Traction Control
- Starting and Charging
- Sensors and Switches - Starting and Charging
- Battery
- Charging System
- Starting System
- Power and Ground Distribution
- Technical Service Bulletins
- Power and Ground Distribution
- Steering and Suspension
- Alignment
- Sensors and Switches - Steering and Suspension
- Steering
- Suspension
- Wheels and Tires
- Technical Service Bulletins
- Heating and Air Conditioning
- Air Conditioning Switch
- Blower Motor
- Blower Motor Switch
- Compressor HVAC
- Compressor Clutch Relay
- Condenser HVAC
- Condenser Fan
- Evaporator Core
- Heater Core
- Refrigerant
- Refrigerant Oil
- Relays and Modules - HVAC
- Sensors and Switches - HVAC
- Service Port HVAC
- Service Precautions
- Testing and Inspection
- Service and Repair
- Diagrams
- Technical Service Bulletins
- Restraints and Safety Systems
- Seat Belt Systems
- Sensors and Switches - Restraints and Safety Systems
- Technical Service Bulletins
- Accessories and Optional Equipment
- Body and Frame
- Cruise Control
- Cruise Control Brush Assembly
- Cruise Control Module
- Cruise Control Servo
- Cruise Control Servo Cable
- Cruise Control Switch
- Relays and Modules - Cruise Control
- Sensors and Switches - Cruise Control
- Description and Operation
- Testing and Inspection
- SP1: Speed Control System Check
- SP2: System Voltage Check (Will Not Set)
- SP3: Set Switch Check (Will Not Set)
- SP4: Set Switch Check (Will Not Set)
- SP5: Combination Switch Ground Check (Will Not Set)
- SP6: Actuator Solenoid Valve Check (Will Not Set)
- SP7: Speed Signal Check (Will Not Set)
- SP8: Speed Sensor Signal Check (Will Not Set)
- SP9: Instrument Fuse Check (Will Not Set)
- SP10: Speed Control Supply Check (Will Not Set)
- SP11: VAC Signal Check (Will Not Set)
- SP12: Vent 2 Signal Check (Will Not Set)
- SP13: Vent 1 Signal Check (Will Not Set)
- SP14: Clutch Switch Check (Will Not Set)
- SP15: Stop Switch Check (Will Not Set)
- SP16: Combination Switch Check (Will Not Set)
- SP17 - 20: Clutch Switch Check (Will Not Disengage)
- SP18 - 19: Stop Switch Check (Will Not Disengage)
- SP21: Coast Switch Check (Will Not Coast)
- SP22: Coast Switch Check (Will Not Coast)
- SP23: Resume Switch Check (Will Not Resume)
- SP24: Resume Signal Check (Will Not Resume)
- SP25: Actuator Solenoid Valve Check (Speed Fluctuates)
- SP26: Speed Signal Check (Speed Fluctuates)
- SP27: Speed Sensor Signal Check (Speed Fluctuates)
- Diagrams
- Technical Service Bulletins
- Instrument Panel, Gauges and Warning Indicators
- Audible Warning Device
- Brake Warning Indicator
- Charge Lamp/Indicator
- Cigarette Lighter
- Clock
- Dashboard / Instrument Panel
- Door Switch
- Fuel Gauge
- Fuel Gauge Sender
- Instrument Cluster / Carrier
- Lamp Out Indicator
- Malfunction Indicator Lamp
- Odometer
- Oil Level Warning Indicator
- Oil Pressure Gauge
- Oil Pressure Sender
- Oil Pressure Warning Lamp/Indicator
- Seat Belt Reminder Buzzer
- Seat Belt Reminder Lamp
- Sensors and Switches - Instrument Panel
- Speedometer Head
- Temperature Gauge
- Temperature Sensor (Gauge)
- Temperature Warning Lamp/Indicator
- Volt Meter Gauge
- Diagrams
- Technical Service Bulletins
- Lighting and Horns
- Windows and Glass
- Wiper and Washer Systems
- Application and ID
- Locations
- Diagrams
- Diagram Information and Instructions
- Connector Views
- Electrical Diagrams
- Power and Ground Distribution
- Charging System
- Cooling System
- Cruise Control
- Heated Glass Element
- Heating and Air Conditioning
- Instrument Panel, Gauges and Warning Indicators
- Lighting and Horns
- Mirrors
- Powertrain Management
- Radio/Stereo
- Starting System
- Wiper and Washer Systems
- Mechanical Diagrams
- Vacuum and Vapor Hose Diagrams
- Connectors
- Grounds
- Splices
- Specifications
- Electrical Specifications
- Alternator
- Battery
- Computers and Control Systems
- Emission Control Systems
- Firing Order
- Ignition Cable
- Ignition Coil
- Pick-Up Coil, Ignition
- Starter Motor
- Voltage Regulator
- Mechanical Specifications
- Alignment
- Automatic Transmission/Transaxle
- Axle Beam
- Axle Nut
- Ball Joint
- Battery
- Brake Caliper
- Brake Drum
- Brake Hose/Line
- Brake Master Cylinder
- Brake Rotor/Disc
- Compressor Clutch
- Control Arm
- Distributor Advance Unit
- Engine
- Flex Plate
- Flywheel
- Front Steering Knuckle
- Fuel Injector
- Idle Speed
- Ignition Timing
- Lateral Stabilizer Rod
- Manual Transmission/Transaxle
- Neutral Safety Switch
- Radiator Cooling Fan Temperature Sensor / Switch
- Rear Knuckle
- Seat Belt Systems
- Spark Plug
- Spindle
- Stabilizer Bar, Sway Control
- Starter Motor
- Steering Gear
- Suspension Strut / Shock Absorber
- Tie Rod
- Wheel Cylinder
- Wheel Stud / Lug Nut
- Pressure, Vacuum and Temperature Specifications
- Capacity Specifications
- Fluid Type Specifications
- Electrical Specifications
- Technical Service Bulletins
Diagnostic Trouble Codes