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 - Cruise Control
- Relays and Modules - HVAC
- Relays and Modules - Instrument Panel
- Relays and Modules - Lighting and Horns
- Relays and Modules - Powertrain Management
- Relays and Modules - Starting and Charging
- Relays and Modules - Steering and Suspension
- Relays and Modules - Transmission and Drivetrain
- Relays and Modules - Windows and Glass
- 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
- 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
- Sensors and Switches - Starting and Charging
- Sensors and Switches - Steering and Suspension
- Sensors and Switches - Transmission and Drivetrain
- Sensors and Switches - Windows and Glass
- Sensors and Switches - Wiper and Washer Systems
- Maintenance
- Alignment
- Tune-up and Engine Performance Checks
- Drive Belt
- Filters
- Hoses
- Fluids
- Brake Bleeding
- Fuses and Circuit Breakers
- Service Reminder Indicators
- Wheels and Tires
- Application and ID
- 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
Service and Repair
Specifications
Technical Service Bulletins
- Engine, Cooling and Exhaust
- Engine
- Compression Check
- 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
Locations- Service and Repair
- Technical Service Bulletins
- Cooling System
- Coolant
- Coolant Level Indicator Lamp
- Radiator Cooling Fan
- Engine - Coolant Temperature Sensor/Switch
- Heater Control Valve
- Heater Core
- Lamps and Indicators - Cooling System
- Radiator
- Radiator Cap
- Sensors and Switches - Cooling System
- Temperature Gauge
- Temperature Warning Lamp/Indicator
- Thermostat
- Water Pump
- Specifications
- Technical Service Bulletins
- Exhaust System
- Technical Service Bulletins
- Engine
- Powertrain Management
- Relays and Modules - Powertrain Management
- Sensors and Switches - Powertrain Management
- Tune-up and Engine Performance Checks
- Computers and Control Systems
- Air Flow Meter/Sensor
- Air Temperature Sensor ( Ambient / Intake )
- Barometric Pressure Sensor
- Coolant Temperature Sensor/Switch (For Computer)
- Data Link Connector
- Electronic Spark Control Module
- Engine Control Module
- Idle Speed/Throttle Actuator - Mechanical
- Idle Up Control Valve
- Idle/Throttle Speed Control Unit
- Knock Sensor
- Malfunction Indicator Lamp
- Manifold Pressure/Vacuum Sensor
- Memory Calibration Unit
- Mixture Control Solenoid
- Oil Pressure Sensor
- Oxygen Sensor
- Relays and Modules - Computers and Control Systems
- Sensors and Switches - Computers and Control Systems
- 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
- Symptom Related Diagnostic Procedures
- Component Tests and General Diagnostics
- Scan Tool Testing and Procedures
Adjustments
Diagrams- Technical Service Bulletins
Tools and Equipment
- Emission Control Systems
- Air Injection
- Catalytic Converter
- Early Fuel Evaporation ( EFE )
- Evaporative Emissions System
- Exhaust Gas Recirculation
- Positive Crankcase Ventilation
- Relays and Modules - Emission Control Systems
- Thermostatic Air Cleaner
- Vacuum Restrictor
- Locations
- Diagrams
- Technical Service Bulletins
- Fuel Delivery and Air Induction
- Fuel Pressure
- Fuel Pressure Release
- Idle Speed
- Air Cleaner Housing
- Air Flow Meter/Sensor
- Altitude Compensator
- Carburetor
- Carburetor Base Gasket
- Carburetor Float
- Choke Pull-off
- Choke Thermostat/Heater
- Thermal Vacuum Valve - Carb
- Application and ID
- Description and Operation
- Testing and Inspection
- Adjustments
- Choke Cover Removal
- Float Level
- Choke Coil Lever
- Choke Rod
- Air Bleed Hole Blocking Procedure
- Front Vacuum Break Adjustment
- Rear Vacuum Break Adjustment
- Air Valve Dashpot Adjustment
- Choke Unloader Adjustment
- Secondary Throttle Valve Lockout Adjustment
- Air Valve Spring Wind-Up
- Idle Load Compensator (ILC)
- Idle Speed Control (ISC)
- Throttle Position Sensor (TPS)
- Service and Repair
- Specifications
- Technical Service Bulletins
- Cold Start Solenoid (For Injection Pump)
- Diesel MFI Pump
- Fuel
- Fuel Filler Cap
- Fuel Filter
- Fuel Heater
- Fuel Injector
- Fuel Pump
- Fuel Tank
- Fuel Tank Unit
- Idle Speed/Throttle Actuator - Mechanical
- Idle Up Control Valve
- Idle/Throttle Speed Control Unit
- Relays and Modules - Fuel Delivery and Air Induction
- Sensors and Switches - Fuel Delivery and Air Induction
- Throttle Position Sensor
- Turbocharger
- Service Precautions
- Description and Operation
- Adjustments
- Diagrams
- Specifications
- Technical Service Bulletins
- Tools and Equipment
- Ignition System
- Firing Order
- Ignition Timing
- Distributor
- Electronic Spark Control Module
- Ignition Cable
- Ignition Coil
- Knock Sensor
- Pick-Up Coil
- Relays and Modules - Ignition System
- Sensors and Switches - Ignition System
- Spark Plug
- Thermal Vacuum Valve
- Vacuum Advance Control Solenoid
- Vacuum Restrictor
- Description and Operation
- Service and Repair
- Technical Service Bulletins
- Transmission Control Systems
- PROM - Programmable Read Only Memory
- Service Precautions
- Application and ID
- Diagrams
- Technical Service Bulletins
- Transmission and Drivetrain
- Actuators and Solenoids - Transmission and Drivetrain
- Automatic Transmission/Transaxle
- Actuators and Solenoids - A/T
- Accumulator
- Band
- Clutch
- Differential
- Drive Chain
- Fluid - A/T
- Fluid Filter - A/T
- Fluid Line/Hose
- Fluid Pan
- Fluid Pressure Sensor/Switch
- Fluid Pump
- Governor
- Input Shaft
- Output Shaft
- Park Gear
- Parking Pawl
- Planetary Gears
- Relays and Modules - A/T
- Seals and Gaskets
- Sensors and Switches - A/T
- Shifter A/T
- Shift Linkage
- Sun Gear
- Throttle Valve Cable/Linkage
- Thrust Washer/Bearing
- Torque Converter
- Torque Converter Clutch
- Torque Converter Clutch Relay
- Torque Converter Clutch Solenoid
- Transmission Cooler
- Transmission Position Sensor/Switch
- Transmission Pressure Test Port
- Valve Body
- Application and ID
- Description and Operation
- Description
- Power Flow
- Detent Downshift Valves In Second Gear Position
- Drive Range-Overdrive
- Drive Range-1ST Gear
- Drive Range-2ND Gear (Converter Clutch Applied)
- Drive Range-2nd Gear (Converter Clutch Released)
- Drive Range-3RD Gear
- Manual Lo Gear
- Manual Second Gear
- Manual Third Gear
- Neutral-Engine Running
- Park-Engine Running
- Part Throttle 4-3 Modulated Downshift Valves In 3RD Gear
- Reverse Range
- Testing and Inspection
- Service and Repair
- Procedures
- Removal and Replacement
- Overhaul
- Disassemble
- Assemble
- Transmission Case
- Manual Shaft & Parking Pawl
- Reaction Gear Output Shaft
- Reaction Internal Gear
- Roller Clutch & Reaction Carrier
- Lo-Reverse Clutch & Spacer
- Lo & Reverse Clutch Housing
- Reaction Sun Gear & Input Drum
- Input Sun Gear
- Input Carrier Assembly
- Input Gear & Selective Thrust Washer
- Reaction Selective Thrust Washer
- Checking Reaction Unit Endplay
- Direct Clutch Assembly
- Forward Clutch Housing
- Intermediate Band
- Forward & Direct Clutch
- Case Cover, Drive & Driven Sprocket Supports
- Oil Pump
- Drive Link, Sprockets & Sprocket Cover
- Fourth Clutch Assembly
- Overdrive Internal Gear
- Overrun Clutch Assembly
- Overdrive Carrier Assembly
- Governor & Speedometer Drive Gear
- Intermediate Servo Piston
- LO & Reverse Clutch Housing to Case Cup Plug
- Control Valve Assembly
- Pressure Regulator Assembly
- Converter Clutch Valve
- Oil Pan & Torque Converter
- Diagrams
- Specifications
- Technical Service Bulletins
- Clutch
- Continuously Variable Transmission/Transaxle
- Differential Assembly
- Drive Axles, Bearings and Joints
- Drive/Propeller Shafts, Bearings and Joints
- Flex Plate
- Manual Transmission/Transaxle
- Relays and Modules - Transmission and Drivetrain
- Sensors and Switches - Transmission and Drivetrain
- Transfer Case
- Transmission Control Systems
- Diagrams
- Technical Service Bulletins
- Brakes and Traction Control
- Antilock Brakes / Traction Control Systems
- Brake Bleeding
- Brake Warning Indicator
- Disc Brake System
- Drum Brake System
- Hydraulic System
- Parking Brake System
- Power Brake Assist
- Sensors and Switches - Brakes and Traction Control
- Service Precautions
- Testing and Inspection
- Service and Repair
- Technical Service Bulletins
- Starting and Charging
- Sensors and Switches - Starting and Charging
- Relays and Modules - Starting and Charging
- Battery
- Charging System
- Starting System
- Power and Ground Distribution
- Service Precautions
- Testing and Inspection
- Diagrams
- Specifications
- Technical Service Bulletins
- Power and Ground Distribution
- Steering and Suspension
- Alignment
- Relays and Modules - Steering and Suspension
- Sensors and Switches - Steering and Suspension
- Steering
- Front Steering Knuckle
- Power Steering
- Steering Column
- Steering Gear
- Steering Wheel
- Service Precautions
- Technical Service Bulletins
- Suspension
- Axle Beam
- Ball Joint
- Control Arm
- Front Steering Knuckle
- Relays and Modules - Suspension
- Sensors and Switches - Suspension
- Stabilizer Bar
- Suspension Control ( Automatic - Electronic )
- Suspension Spring ( Coil / Leaf )
- Suspension Strut / Shock Absorber
- Torsion Bar
- Wheel Bearing
- Description and Operation
- Adjustments
- Specifications
- Technical Service Bulletins
- Wheels and Tires
- Technical Service Bulletins
- Heating and Air Conditioning
- Accumulator HVAC
- Air Conditioning Switch
- Air Door
- Blower Motor
- Blower Motor Relay
- Blower Motor Resistor
- Blower Motor Switch
- Cabin Temperature Sensor / Switch
- Compressor HVAC
- Compressor Clutch
- Compressor Clutch Coil
- Compressor Shaft Seal
- Service and Repair
- Diagrams
- Technical Service Bulletins
- Compressor Clutch Diode HVAC
- Condenser HVAC
- Control Assembly
- Control Module HVAC
- Evaporator Core
- Expansion Block/Orifice Tube
- Heater Control Valve
- Heater Core
- Housing Assembly HVAC
- Refrigerant
- Refrigerant Oil
- Refrigerant Pressure Sensor / Switch
- Relays and Modules - HVAC
- Sensors and Switches - HVAC
- Service Port HVAC
- Vacuum Check Valve HVAC
- Vacuum Controller
- Vacuum Reservoir HVAC
- Vacuum Solenoid Valve HVAC
- Service Precautions
- Description and Operation
- Testing and Inspection
- Initial Inspection and Diagnostic Overview
- Symptom Related Diagnostic Procedures
- Component Tests and General Diagnostics
- Component Diagnostic Charts/Tests
- Functional Test/Check
- Leak Testing - Refrigerant System
- Programmer Control Lever, Adjust - Tempmatic Climate Control System
- System Diagnostic Charts - Cycling Clutch Orifice Tube (CCOT)
- System Performance Test
- Temperature Controls Diagnosis - Tempmatic Climate Control System
- Service and Repair
- Diagrams
- Specifications
- Technical Service Bulletins
- Restraints and Safety Systems
- Accessories and Optional Equipment
- Body and Frame
- Bumper
- Doors, Hood and Trunk
- Exterior Moulding / Trim
- Frame
- Interior Moulding / Trim
- Locks
- Mirrors
- Paint, Striping and Decals
- Relays and Modules - Body and Frame
- Roof and Associated Components
- Seats
- Sensors and Switches - Body and Frame
- Weatherstrip
- Technical Service Bulletins
- Cruise Control
- Instrument Panel, Gauges and Warning Indicators
- Ammeter Gauge
- Audible Warning Device
- Audible Warning Device Control Module
- Brake Warning Indicator
- Charge Lamp/Indicator
- Cigarette Lighter
- Clock
- Coolant Level Indicator Lamp
- Dashboard / Instrument Panel
- Dimmer Switch
- Door Switch
- Fuel Gauge
- Fuel Gauge Sender
- Instrument Cluster / Carrier
- Key Reminder Switch
- Low Fuel Lamp/Indicator
- Malfunction Indicator Lamp
- Odometer
- Oil Level Warning Indicator
- Oil Pressure Warning Lamp/Indicator
- Parking Brake Warning Lamp
- Relays and Modules - Instrument Panel
- Seat Belt Reminder Lamp
- Sensors and Switches - Instrument Panel
- Speedometer Head
- Temperature Gauge
- Temperature Warning Lamp/Indicator
- Tire Monitoring System
- Transmission Shift Position Indicator Lamp
- Vacuum Gauge/Economy Meter
- Volt Meter Gauge
- Description and Operation
- Testing and Inspection
- Diagrams
- Technical Service Bulletins
- Lighting and Horns
- Ambient Light Sensor
- Backup Lamp
- Brake Lamp
- Brake Light Switch
- Cornering Lamp
- Courtesy Lamp
- Dimmer Switch
- Door Switch
- Fog/Driving Lamp
- Hazard Warning Lamps
- Headlamp
- Horn
- Interior Lighting Module
- License Plate Lamp
- Marker Lamp
- Parking Lamp
- Relays and Modules - Lighting and Horns
- Sensors and Switches - Lighting and Horns
- Tail Lamp
- Trunk Lamp
- Turn Signals
- Application and ID
- Diagrams
- Technical Service Bulletins
- Windows and Glass
- Wiper and Washer Systems
- Application and ID
- Regular Production Option (RPO)
- Vehicle Identification Number (VIN)
- Description
- GM Automobile VIN Charts
- GM Light Duty & Multi-Purpose Truck VIN Charts
- 1982 Light Duty Trucks & Multi-Purpose Vehicle
- 1983 Light Duty Trucks & Multi-Purpose Vehicle
- 1984 Light Duty Trucks & Multi-Purpose Vehicle
- 1985 Light Duty Trucks & Multi-Purpose Vehicle
- 1986 Light Duty Trucks & Multi-Purpose Vehicle
- 1987 Light Duty Trucks & Multi-Purpose Vehicle
- 1988 Light Duty Trucks & Multi-Purpose Vehicle
- 1989 Light Duty Trucks & Multi-Purpose Vehicle
- 1990 Light Duty Trucks & Multi-Purpose Vehicles
- 1991 Light Duty Trucks & Multi-Purpose Vehicles
- 1992 Light Duty Trucks & Multi-Purpose Vehicles
- 1993 Light Duty Trucks & Multi-Purpose Vehicles
- 1994 Light Duty Trucks & Multi-Purpose Vehicles
- 1995 Light Duty Trucks & Multi-Purpose Vehicles
- 1996 Light Duty Trucks & Multi-Purpose Vehicles
- GM Medium & Heavy Duty Truck VIN Charts
- 1982 Medium & Heavy Duty Trucks
- 1983 Medium & Heavy Duty Trucks
- 1984 Medium & Heavy Duty Trucks
- 1985 Medium & Heavy Duty Trucks
- 1986 Medium & Heavy Duty Trucks
- 1987 Medium & Heavy Duty Trucks
- 1988 Medium & Heavy Duty Trucks
- 1989 Medium & Heavy Duty Trucks
- 1990 Medium & Heavy Duty Trucks
- 1991 Medium & Heavy Duty Trucks
- 1992 Medium & Heavy Duty Trucks
- 1993 Medium & Heavy Duty Trucks
- 1994 Medium & Heavy Duty Trucks
- 1995 Medium & Heavy Duty Trucks
- 1996 Medium & Heavy Duty Trucks
- Locations
- Component Locations
- Additional Information
- Miscellaneous Components
- A/C Control Head
- A/C Programmer
- A/C Vacuum Valve
- Air Diverter Valve
- Automatic Door Lock Controller
- Automatic Door Lock Diode
- Auxiliary Wire
- Blower Resistors
- CB Transceiver
- Check Valve
- Cold Start Program Modifier
- Convenience Center
- Coolant Temperature Sender
- Cruise Control Servo
- Defogger
- Defogger Control & Indicator
- EFE Valve
- ELC Compressor Assembly
- Electronic Spark Control
- Flow Restricter
- Fuel Gauge Sender
- Fuel Tank Unit
- Fuse Block
- Fuse Link C
- Fuse Link D
- Fuse Link E
- Fuse Link F
- Heater Water Valve
- Horn Brush/Slip Ring
- Illuminated Entry Timer
- Inline Fuse A & B
- Multi-Function Lever
- Noise Suppression Capacitors
- Seat Transmission
- Sentinel Amplifier
- Sentinel Control
- Sentinel Photocell
- Splitter
- Theft Deterrent Controller
- Theft Deterrent Diode Assembly
- Torque Converter Clutch
- Turn Flasher
- Vacuum Release Valve
- Vacuum Tank
- Wiper/Washer Control
- 6-Way Fiber Optic Source
- Modules
- Motors
- Relays
- Sensors
- Solenoids
- Switches
- Altitude Switch
- Booster Low Vacuum Switch
- Brake Switch
- Door Handle Switch
- Door Lock Cylinder Switches
- Engine Oil Pressure Switch
- Gear Selector Switch
- Governor Pressure Switch
- Hazard Switch
- Headlight Dimmer Switch
- Horn Switch
- Ignition Key Warning Switch
- Ignition Switch
- LH Front Master Switch Assembly
- LH Outside Mirror Switch
- Memory Control Switch Assembly
- Park Brake Switch
- Pressure Cycling Switch
- RH Front Door Jamb Switch
- RH Power Seat Recliner Switch
- Seat Belt Switch
- Sunroof Switch Assembly
- Thermal Relay Blower Switch
- Trunk Lid Tamper Switch
- Turn/Hazard Switch
- Vacuum Regulator Valve Switch
- Connector Locations
- Fuse and Fusible Link Locations
- Ground Locations
- Splice Locations
- Component Locations
- Diagrams
- Diagram Information and Instructions
- Diagnostic Aids
- Exploded Views
- Connector Views
- Electrical Diagrams
- Cell References
- Antenna
- Antitheft and Alarm Systems
- Brake Warning Indicator
- Heated Glass Element
- Heating and Air Conditioning
- Instrument Panel, Gauges and Warning Indicators
- Lighting and Horns
- Mirrors
- Power Locks
- Powertrain Management
- Radio, Stereo, and Compact Disc
- Seat Belt Systems
- Seats
- Starting and Charging
- Sunroof / Moonroof
- Suspension Control ( Automatic - Electronic )
- Trailer Adapter Kit
- Transmission and Drivetrain
- Trunk / Liftgate Solenoid
- Windows
- Wiper and Washer Systems
- Fluid Diagrams
- Vacuum and Vapor Hose Diagrams
- Components
- Additional Information
- Miscellaneous Components
- A/C Control Head
- A/C Programmer
- A/C Vacuum Valve
- Air Diverter Valve
- Automatic Door Lock Controller
- Automatic Door Lock Diode
- Auxiliary Wire
- Blower Resistors
- CB Transceiver
- Check Valve
- Cold Start Program Modifier
- Convenience Center
- Coolant Temperature Sender
- Cruise Control Servo
- Defogger
- Defogger Control & Indicator
- EFE Valve
- ELC Compressor Assembly
- Electronic Spark Control
- Flow Restricter
- Fuel Gauge Sender
- Fuel Tank Unit
- Fuse Block
- Fuse Link C
- Fuse Link D
- Fuse Link E
- Fuse Link F
- Heater Water Valve
- Horn Brush/Slip Ring
- Illuminated Entry Timer
- Inline Fuse A & B
- Multi-Function Lever
- Noise Suppression Capacitors
- Seat Transmission
- Sentinel Amplifier
- Sentinel Control
- Sentinel Photocell
- Splitter
- Theft Deterrent Controller
- Theft Deterrent Diode Assembly
- Torque Converter Clutch
- Turn Flasher
- Vacuum Release Valve
- Vacuum Tank
- Wiper/Washer Control
- 6-Way Fiber Optic Source
- Modules
- Motors
- Relays
- Sensors
- Solenoids
- Switches
- Altitude Switch
- Booster Low Vacuum Switch
- Brake Switch
- Door Handle Switch
- Door Lock Cylinder Switches
- Engine Oil Pressure Switch
- Gear Selector Switch
- Governor Pressure Switch
- Hazard Switch
- Headlight Dimmer Switch
- Horn Switch
- Ignition Key Warning Switch
- Ignition Switch
- LH Front Master Switch Assembly
- LH Outside Mirror Switch
- Memory Control Switch Assembly
- Park Brake Switch
- Pressure Cycling Switch
- RH Front Door Jamb Switch
- RH Power Seat Recliner Switch
- Seat Belt Switch
- Sunroof Switch Assembly
- Thermal Relay Blower Switch
- Trunk Lid Tamper Switch
- Turn/Hazard Switch
- Vacuum Regulator Valve Switch
- Connectors
- Fuse and Fusible Links
- Grounds
- Splices
- Specifications
- Electrical Specifications
- Air Temperature Sensor ( Ambient / Intake )
- Alternator
- Barometric Pressure Sensor
- Battery
- Coolant Temperature Sensor/Switch (For Computer)
- Engine Control Module
- Idle/Throttle Speed Control Unit
- Ignition Coil
- Ignition Timing
- Manifold Pressure/Vacuum Sensor
- Mixture Control Solenoid
- Pick-Up Coil, Ignition
- Throttle Position Sensor
- Voltage Regulator
- Mechanical Specifications
- Alignment
- Automatic Transmission/Transaxle
- Brake Master Cylinder
- Brake Rotor/Disc
- Camshaft, Lifters and Push Rods
- Clutch Linkage
- Cylinder Block Assembly
- Cylinder Head Assembly
- Differential Assembly
- Distributor, Ignition
- Drive Belt
- Exhaust Manifold
- Firing Order
- Flex Plate
- Fuel Delivery and Air Induction
- Intake Manifold
- Oil Pressure Sensor
- Oil Pump, Engine
- Spark Plug
- Starting and Charging
- Suspension
- Wheel Cylinder
- Wheel Stud / Lug Nut
- Pressure, Vacuum and Temperature Specifications
- Capacity Specifications
- Fluid Type Specifications
- Electrical Specifications
- Technical Service Bulletins
Diagnostic Trouble Codes