Repair and Diagnosis

A L L Diagnostic Trouble Codes ( DTC )
Relays and Modules
- Relays and Modules - Accessories and Optional Equipment
- Relays and Modules - Body and Frame
- Relays and Modules - Brakes and Traction Control
  - Electronic Brake Control Module
- Relays and Modules - Cooling System
  - Radiator Cooling Fan Control Module
  - Radiator Cooling Fan Motor Relay
- Relays and Modules - Cruise Control
  - Cruise Control Module
- Relays and Modules - HVAC
- Relays and Modules - Instrument Panel
  - Fuel Distance/Mileage Module
- Relays and Modules - Lighting and Horns
- Relays and Modules - Power and Ground Distribution
  - Power Distribution Relay
  - Relay Box
- Relays and Modules - Powertrain Management
- Relays and Modules - Restraints and Safety Systems
  - Air Bag Control Module
- Relays and Modules - Starting and Charging
- Relays and Modules - Steering and Suspension
  - Relays and Modules - Steering
    - Steering Mounted Controls Communication Module
- Relays and Modules - Transmission and Drivetrain
  - Relays and Modules - A/T
    - Control Module
    - Transmission Position Relay
- Relays and Modules - Windows and Glass
  - Power Window Control Module
- Relays and Modules - Wiper and Washer Systems
Sensors and Switches
- Sensors and Switches - Accessories and Optional Equipment
- 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
  - Oil Pressure Sender
- Sensors and Switches - HVAC
- Sensors and Switches - Instrument Panel
- Sensors and Switches - Lighting and Horns
- Sensors and Switches - Powertrain Management
- Sensors and Switches - Restraints and Safety Systems
  - Impact Sensor
  - Seat Belt Buckle Switch
- Sensors and Switches - Starting and Charging
  - Clutch Switch
  - Ignition Switch
- Sensors and Switches - Steering and Suspension
  - Sensors and Switches - Steering
    - Power Steering Pressure Switch
    - Steering Angle Sensor
  - Sensors and Switches - Suspension
    - Steering Angle Sensor
- Sensors and Switches - Transmission and Drivetrain
  - Sensors and Switches - A/T
- Sensors and Switches - Windows and Glass
  - Heated Glass Element Switch
  - Power Window Switch
- 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
  - Hose/Line HVAC
  - Service Precautions
- Fluids
- Brake Bleeding
- Air Bag(s) Arming and Disarming
- Fuses and Circuit Breakers
- Service Reminder Indicators
- Wheels and Tires
- Service Precautions
- Application and ID
- Service Intervals
  - Supplemental Service Items
    - Every 1 Year
    - Every 2 Years
  - Normal Service
- Locations
- Service and Repair
- Technical Service Bulletins
Engine, Cooling and Exhaust
- Engine
- Cooling System
- Exhaust System
- Technical Service Bulletins
Powertrain Management
- Relays and Modules - Powertrain Management
- Sensors and Switches - Powertrain Management
- Tune-up and Engine Performance Checks
- Computers and Control Systems
- Emission Control Systems
- Fuel Delivery and Air Induction
- Ignition System
- Transmission Control Systems
- PROM - Programmable Read Only Memory
- Service Precautions
- Diagrams
  - Diagram Information and Instructions
  - Electrical Diagrams
- Technical Service Bulletins
Transmission and Drivetrain
- Actuators and Solenoids - Transmission and Drivetrain
  - Actuators and Solenoids - A/T
    - Shift Interlock Solenoid
- Automatic Transmission/Transaxle
- Clutch
- Differential Assembly
- Drive Axles, Bearings and Joints
- Flex Plate
- Flywheel
- Manual Transmission/Transaxle
- Relays and Modules - Transmission and Drivetrain
  - Relays and Modules - A/T
    - Control Module
    - Transmission Position Relay
- Sensors and Switches - Transmission and Drivetrain
  - Sensors and Switches - A/T
- Transmission Control Systems
- Service Precautions
- Technical Service Bulletins
- Tools and Equipment
Brakes and Traction Control
- Antilock Brakes / Traction Control Systems
- Brake Bleeding
- Brake Pedal Assy
- Disc Brake System
- Hydraulic System
- Parking Brake System
- Power Brake Assist
- Relays and Modules - Brakes and Traction Control
  - Electronic Brake Control Module
- Sensors and Switches - Brakes and Traction Control
- Specifications
  - Brake Rotor
  - Brake Caliper
- Technical Service Bulletins
Starting and Charging
- Sensors and Switches - Starting and Charging
  - Clutch Switch
  - Ignition Switch
- Relays and Modules - Starting and Charging
- Battery
- Charging System
- Starting System
- Power and Ground Distribution
- Diagrams
  - Diagram Information and Instructions
  - Electrical Diagrams
- Technical Service Bulletins
Power and Ground Distribution
- Auxiliary Power Outlet
- Fuse
- Fuse Block
- Ground Strap
- Grounding Point
- Multiple Junction Connector
- Power Distribution Relay
- Relays and Modules - Power and Ground Distribution
  - Power Distribution Relay
  - Relay Box
- Relay Box
- Wiring Harness
- Service and Repair
  - Cable Channel In Engine Compartment, Removing and Installing
  - Protective Housing In Plenum Chamber, Removing and Installing
- Diagrams
  - Diagram Information and Instructions
  - Electrical Diagrams
    - Standard Equipment - Jetta Wagon, From January 2001
    - Standard Equipment - Golf/Jetta, From January 2001
- Technical Service Bulletins
Steering and Suspension
- Alignment
- Relays and Modules - Steering and Suspension
  - Relays and Modules - Steering
    - Steering Mounted Controls Communication Module
- Sensors and Switches - Steering and Suspension
  - Sensors and Switches - Steering
    - Power Steering Pressure Switch
    - Steering Angle Sensor
  - Sensors and Switches - Suspension
    - Steering Angle Sensor
- Steering
- Suspension
- Wheels and Tires
- Application and ID
- Description and Operation
- Specifications
- Technical Service Bulletins
Heating and Air Conditioning
- Air Door
  - Air Door Actuator / Motor
  - Air Door Cable
  - Service and Repair
  - Technical Service Bulletins
- Air Duct
- Air Register
- Ambient Temperature Sensor / Switch HVAC
- Blower Motor
- Blower Motor Resistor
- Blower Motor Switch
- Cabin Air Filter / Purifier
- Cabin Ventilation Duct
- Compressor HVAC
  - Compressor Clutch
  - Compressor Clutch Coil
  - Compressor Pulley
  - Description and Operation
  - Testing and Inspection
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Specifications
- Compressor Clutch Relay
- Condenser HVAC
- Condenser Fan
- Condenser Fan Motor Relay
- Control Assembly
- Control Module HVAC
- Coupler HVAC
  - A/C Coupler O-ring
- Discharge Air Temperature Sensor / Switch
- Evaporator Case
- Evaporator Core
- Evaporator Drain Tube
- Expansion Valve
- Heater Core
- Heater Core Case
- High Pressure Safety Valve HVAC
- Hose/Line HVAC
- Housing Assembly HVAC
- Receiver Dryer
- Refrigerant
- Refrigerant Oil
- Refrigerant Pressure Sensor / Switch
  - A/C Pressure Sensor/Switch - Cooling Fan
  - High Pressure Sensor / Switch
  - Low Pressure Sensor / Switch
  - Description and Operation
    - A/C Pressure Switch -F129-
    - High Pressure Sensor -G65-
  - Testing and Inspection
    - A/C Pressure Switch -F129-
    - High Pressure Sensor - G65 -
  - Locations
- Relays and Modules - HVAC
  - Compressor Clutch Relay
  - Condenser Fan Motor Relay
  - Control Module HVAC
- Sensors and Switches - HVAC
  - Ambient Temperature Sensor / Switch HVAC
  - Blower Motor Switch
  - Discharge Air Temperature Sensor / Switch
  - Refrigerant Pressure Sensor / Switch
  - Solar Sensor
  - Superheat Switch
- Service Port HVAC
- Solar Sensor
- Superheat Switch
- Service Precautions
- Application and ID
- Description and Operation
  - General Information
  - A/C Refrigerant R-134A, Properties
- Testing and Inspection
  - Reading and Clearing Diagnostic Trouble Codes
  - Component Tests and General Diagnostics
  - Scan Tool Testing and Procedures
- Locations
  - Climatronic Components - Passenger Compartment
  - Climatronic Components - Engine Compartment
- Service and Repair
  - A/C Refrigerant System
  - Climatronic
    - Components In Engine Compartment, Servicing
    - Components In Passenger Compartment, Servicing
  - Heating and A/C
    - Components In Engine Compartment, Servicing
    - Components In Passenger Compartment, Servicing
  - Heating and Ventilation System, Servicing Overview
- Diagrams
  - Diagram Information and Instructions
  - Electrical Diagrams
    - Air Conditioning - Manual, From May 1999
    - Climatronic, From May 1999
- Specifications
  - Pressure, Vacuum and Temperature Specifications
  - Capacity Specifications
- Technical Service Bulletins
- Tools and Equipment
Restraints and Safety Systems
- Repairs and Inspections Required After a Collision
- Air Bag Systems
- Head Restraint System
  - Head Rest
- Relays and Modules - Restraints and Safety Systems
  - Air Bag Control Module
- Seat Belt Systems
- Sensors and Switches - Restraints and Safety Systems
  - Impact Sensor
  - Seat Belt Buckle Switch
- Testing and Inspection
- Technical Service Bulletins
Accessories and Optional Equipment
- Antenna
- Antitheft and Alarm Systems
- Central Control Module
- Driver/Vehicle Information Display
- Global Positioning System
- Memory Positioning Systems
  - Memory Positioning Module
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- Radio, Stereo, and Compact Disc
- Relays and Modules - Accessories and Optional Equipment
- Sensors and Switches - Accessories and Optional Equipment
- Steering Mounted Controls Communication Module
- Towing / Trailer System
  - Trailer Hitch
- Trip Computer
- Technical Service Bulletins
Body and Frame
- Air Bag(s) Arming and Disarming
- Repairs and Inspections Required After a Collision
- Body Control Systems
  - Body Control Module
  - Locations
  - Service and Repair
- Bumper
  - Front Bumper
  - Rear Bumper
    - Rear Bumper Cover / Fascia
    - Rear Bumper Reinforcement
- Cabin Ventilation Duct
- Cowl
  - Cowl Moulding / Trim
- Doors, Hood and Trunk
  - Doors
  - Fuel Door
  - Hood
  - Trunk / Liftgate
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
- Exterior Moulding / Trim
  - Cowl Moulding / Trim
- Fender
  - Front Fender
    - Front Fender Liner
    - Service and Repair
- Frame
  - Subframe
  - Trailer Hitch
- Grille
- Interior Moulding / Trim
  - Arm Rest
  - Ash Tray
  - Cargo Cover
  - Carpet
  - Console
  - Dashboard / Instrument Panel
  - Drink Holders
  - Glove Compartment
  - Headliner
  - Passenger Assist Handle
  - Rear Shelf
  - Scuff Plate
  - Sun Visor
  - Trim Panel
  - Technical Service Bulletins
- Locks
  - Door Locks
    - Door Lock Cylinder
    - Door Lock Knob
  - Keyless Entry
  - Power Locks
  - Trunk / Liftgate Lock
  - Trunk / Liftgate Lock Cylinder
  - Testing and Inspection
  - Locations
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
- Mirrors
  - Heated Element
  - Memory Positioning Systems
    - Memory Positioning Module
    - Diagrams
      - Diagram Information and Instructions
        How to Find Wiring Diagrams
        How to Read Track Diagrams
        How to Use Track Diagrams
        Symbols Used In Wiring Diagrams
        Circuit and Terminal Designations
        Wire and Fuse Color Code Identification
        Wire Size Conversion
      - Electrical Diagrams
        Diagram 26/2
        Diagram 26/3
        Diagram 26/4
        Diagram 26/5
        Diagram 26/6
        Diagram 26/7
        Diagram 26/8
        Diagram 26/9
        Diagram 26/10
  - Power Mirror Motor
  - Power Mirror Switch
  - Description and Operation
    - Interior Mirror
    - Automatic Dimming Interior Mirror
  - Testing and Inspection
  - Locations
  - Service and Repair
    - Procedures
    - Removal and Replacement
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- Paint, Striping and Decals
  - Paint
  - Technical Service Bulletins
- Radiator Support
- Relays and Modules - Body and Frame
  - Door Module
  - Memory Positioning Module
  - Power Door Lock Control Module
  - Power Seat Control Module
  - Power Seat Relay
  - Seat Temperature Control Module
  - Sunroof / Moonroof Module
  - Trunk / Liftgate Relay
- Roof and Associated Components
  - Sunroof / Moonroof
  - Technical Service Bulletins
- Seats
  - Head Rest
  - Head Restraint System
    - Head Rest
  - Memory Positioning Systems
    - Memory Positioning Module
    - Diagrams
      - Diagram Information and Instructions
        How to Find Wiring Diagrams
        How to Read Track Diagrams
        How to Use Track Diagrams
        Symbols Used In Wiring Diagrams
        Circuit and Terminal Designations
        Wire and Fuse Color Code Identification
        Wire Size Conversion
      - Electrical Diagrams
        Diagram 26/2
        Diagram 26/3
        Diagram 26/4
        Diagram 26/5
        Diagram 26/6
        Diagram 26/7
        Diagram 26/8
        Diagram 26/9
        Diagram 26/10
  - Power Seat Control Module
  - Power Seat Motor
  - Power Seat Relay
  - Power Seat Switch
  - Seat Cover
  - Seat Temperature Element
  - Seat Temperature Control Module
  - Seat Temperature Sensor
  - Seat Temperature Switch
  - Service Precautions
  - Testing and Inspection
  - Service and Repair
    - Procedures
      - Seat and Mirror Settings For Normal Driving, Storing
      - Seat and Mirror Settings For Normal Driving, Activating
    - Removal and Replacement
      - Front Seat
        Front Seat, Assembly Overview (2-Door)
        Front Seat, Assembly Overview (4-Door)
        Front Seats, Removing and Installing
        Front Backrest, Removing and Installing
        Cable For Locking Backrest, Assembly Overview (2-Door)
        Cable For Locking Backrest, Removing and Installing (2-Door)
        Front Backrest Cover And Upholstery, Removing and Installing
        Front Seat Cover And Upholstery, Removing and Installing
        Lumbar Support, Removing and Installing
        Seat Height Adjuster, Removing and Installing
        8-Way Seat Adjusting Unit, Removing and Installing
        8-Way Seat Backrest Adjustment Drive, Removing and Installing
        8-Way Seat Fore and Aft Adjustment, Removing and Installing
        8-Way Seat Front Height Adjustment Drive, Removing and Installing
        8-Way Seat Rear Height Adjustment Drive, Removing and Installing
        8-Way Seat Trim, Removing and Installing
      - Rear Seat
        Seat Cushion, Removing and Installing
        Seat Cushion With Integrated Child Seat, Removing and Installing
        Backrest, Removing and Installing
        Center Arm Rest, Removing and Installing
        Cover And Cushion For Backrest, Removing and Installing
        Cover And Cushion For Seat Cushion, Removing and Installing
        Cover, Center Arm Rest, Removing and Installing
        Right Backrest Lock, Removing and Installing
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
  - Tools and Equipment
    - Front Seat Cushion And Cover
    - Front Seats
- Sensors and Switches - Body and Frame
  - Fuel Door Switch
  - Hood Switch / Sensor
    - Hood Sensor/Switch (For Alarm)
  - Power Mirror Switch
  - Power Seat Switch
  - Power Trunk / Liftgate Lock Switch
  - Seat Temperature Sensor
  - Seat Temperature Switch
  - Sunroof / Moonroof Switch
- Sound Proofing / Insulation
- Splash Guard
- Spoilers, Flaps, and Air Dams
  - Spoiler
- Strut / Shock Tower
- Unibody
  - Cowl
    - Cowl Moulding / Trim
- Weatherstrip
  - Front Door Weatherstrip
  - Rear Door Weatherstrip
  - Sunroof / Moonroof Weatherstrip
- Service Precautions
  - Environmental Impact Information
  - Technician Safety Information
- Testing and Inspection
- Service and Repair
- Diagrams
  - Diagram Information and Instructions
    - Symbols For Welding Operations
    - Symbols for Working Procedures
  - Electrical Diagrams
- Technical Service Bulletins
Cruise Control
- Brake Switch (Cruise Control)
- Clutch Switch
- Cruise Control Module
- Cruise Control Switch
- Relays and Modules - Cruise Control
  - Cruise Control Module
- Sensors and Switches - Cruise Control
- Testing and Inspection
  - Scan Tool Testing and Procedures
    - Cruise Control System (CCS) Check
    - Description of On-Board Diagnostics
  - Programming and Relearning
- Service and Repair
Instrument Panel, Gauges and Warning Indicators
- Dashboard / Instrument Panel
  - Air Bag(s) Arming and Disarming
  - Service and Repair
    - Instrument Panel, Removing and Installing
    - Instrument Panel Crossmember, Loosening/Tightening
  - Technical Service Bulletins
- Dimmer Switch
- Door Switch
- Driver/Vehicle Information Display
- Electronic Throttle Control Indicator
- Fuel Distance/Mileage Module
- Fuel Gauge
- Fuel Gauge Sender
- Instrument Cluster / Carrier
  - Air Bag(s) Arming and Disarming
  - Description and Operation
  - Testing and Inspection
    - Replacement Instrument Cluster, Adaptation (Function 10)
    - Replacement of Instrument Cluster and Engine Control Module (ECM), Adaptation (Function 10)
  - Locations
    - Component Locations
    - Connector Locations
  - Service and Repair
    - Instrument Cluster, Removing and Installing
    - Notes on Exchanging Instrument Cluster
  - Diagrams
    - Diagram Information and Instructions
    - Connector Views
      - 32-Pin Multi-Pin Connector -T32-, Blue From 05.99
      - 32-Pin Multi-Pin Connector -T32A-, Green From 05.99
  - Technical Service Bulletins
  - Tools and Equipment
- Maintenance Required Lamp/Indicator
- Malfunction Indicator Lamp
- Odometer
- Oil Pressure Sender
- Outside Temperature Display
  - Outside Temperature Display Sensor
- Parking Brake Warning Switch
- Relays and Modules - Instrument Panel
  - Fuel Distance/Mileage Module
- Sensors and Switches - Instrument Panel
  - Dimmer Switch
  - Door Switch
  - Fuel Gauge Sender
  - Outside Temperature Display Sensor
  - Parking Brake Warning Switch
- Transmission Shift Position Indicator Lamp
- Testing and Inspection
- Locations
- Diagrams
  - Diagram Information and Instructions
  - Electrical Diagrams
- Technical Service Bulletins
- Tools and Equipment
Lighting and Horns
- Backup Lamp
  - Backup Lamp Switch
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
- Brake Lamp
- Brake Light Switch
- Center Mounted Brake Lamp
- Courtesy Lamp
  - Door Lamp
  - Glove Box Lamp
  - Glove Box Lamp Switch
  - Service and Repair
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- Daytime Running Lamp
  - Daytime Running Lamp Relay
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- Dimmer Switch
- Door Switch
- Fog/Driving Lamp
  - Fog/Driving Lamp Bulb
  - Fog/Driving Lamp Relay
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
- Hazard Warning Lamps
  - Hazard Flasher Relay
  - Hazard Warning Flasher
  - Hazard Warning Switch
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- Headlamp
  - Headlamp Bulb
  - Headlamp Alignment Actuator
  - Headlamp Alignment Sensor
  - Adjustments
  - Service and Repair
    - Headlights, Removing and Installing
    - Headlight Securing Lugs, Servicing
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
- Horn
  - Horn Relay
  - Horn Switch
  - Locations
    - H1 - Signal Horn/Dual Tone Horn
    - H8 - Alarm Horn
  - Service and Repair
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- License Plate Lamp
- Map Light
- Marker Lamp
- Parking Lamp
  - Parking Light Bulb
  - Diagrams
- Relays and Modules - Lighting and Horns
  - Daytime Running Lamp Relay
  - Fog/Driving Lamp Relay
  - Hazard Flasher Relay
  - Horn Relay
- Sensors and Switches - Lighting and Horns
  - Backup Lamp Switch
  - Brake Light Switch
  - Combination Switch
  - Door Switch
  - Glove Box Lamp Switch
  - Hazard Warning Switch
  - Headlamp Alignment Sensor
  - Horn Switch
  - Trunk Lamp Switch
  - Turn Signal Switch
- Tail Lamp
- Trunk Lamp
  - Trunk Lamp Switch
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
- Turn Signals
  - Combination Switch
  - Turn Signal Flasher
  - Turn Signal Lamp
    - Turn Signal Bulb
  - Turn Signal Switch
  - Service and Repair
    - Procedures
    - Removal and Replacement
  - Diagrams
    - Diagram Information and Instructions
    - Electrical Diagrams
  - Technical Service Bulletins
- Vanity Lamp
- Service Precautions
- Diagrams
  - Diagram Information and Instructions
  - Connector Views
  - Electrical Diagrams
- Technical Service Bulletins
Windows and Glass
- Heated Glass Element
- Relays and Modules - Windows and Glass
  - Power Window Control Module
- Sensors and Switches - Windows and Glass
  - Heated Glass Element Switch
  - Power Window Switch
- Windows
- Windshield
- Service Precautions
- Technical Service Bulletins
Wiper and Washer Systems
- Headlamp Washer Reservoir
- Headlamp Washer Spray Nozzle
- Headlamp Wiper Relay
- Rain Sensor
- Relays and Modules - Wiper and Washer Systems
  - Headlamp Wiper Relay
  - Windshield Washer Relay
  - Wiper Relay
- Sensors and Switches - Wiper and Washer Systems
  - Rain Sensor
  - Washer Fluid Level Switch
  - Wiper Switch
- Washer Fluid Level Indicator
- Washer Fluid Level Switch
- Windshield Washer Pump
- Windshield Washer Relay
- Windshield Washer Reservoir
- Windshield Washer Spray Nozzle
- Wiper Arm
- Wiper Blade
- Wiper Motor
- Wiper Relay
- Wiper Switch
- Service Precautions
  - Technician Safety Information
  - Vehicle Damage Warnings
- Locations
- Service and Repair
- Diagrams
  - Diagram Information and Instructions
  - Connector Views
  - Electrical Diagrams
    - Diagram 59/2
    - Diagram 59/3
- Technical Service Bulletins
- Tools and Equipment
Application and ID
Locations
- Component Locations
- Connector Locations
- Fuse and Fusible Link Locations
- Ground Locations
- Splice Locations
Diagrams
- Diagram Information and Instructions
- Exploded Views
- Connector Views
- Electrical Diagrams
- Mechanical Diagrams
  - Drive Belt
    - With Power Steering Pump and A/C Compressor
    - With Power Steering Pump
- Vacuum and Vapor Hose Diagrams
- Components
- Connectors
- Fuse and Fusible Links
- Grounds
- Splices
Specifications
- Electrical Specifications
  - Fuel Injector
  - Ignition Timing
- Mechanical Specifications
- Pressure, Vacuum and Temperature Specifications
- Capacity Specifications
- Fluid Type Specifications
Technical Service Bulletins
Diagnostic Trouble Codes