VOLKSWAGEN CORRADO 1993 Repair Manual

H - TESTS W/O CODES
Article Text (p. 5)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
ENGINE STALLS WHILE DRIVING
* Check fuel pump.
* Check auxiliary air intake system.
* Check injector fuel pressure and volume.
* Check idle and full throttle switches.
* Check intake air preheating system.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.
POOR PERFORMANCE
* Check fuel pump.
* Check throttle cable adjustment.
* Check auxiliary air intake system.
* Check airflow sensor lever adjustment and control plunger.
* Check throttle potentiometer.
* Check fuel system differential and residual pressures.
* Check injector fuel pressure and volume.
* Check full throttle switch.
* Check mass airflow sensor (if equipped).
* Check intake air preheating system.
* Check catalytic converter.
* Check ignition timing.
ENGINE RUN-ON (DIESELING)
* Check fuel evaporative frequency solenoid(s).
* Check fuel system for leaks.
* Check cold-start valve.
* Check injector fuel pressure and volume.
* Check airflow sensor lever adjustment and control plunger.
HIGH FUEL CONSUMPTION
* Check fuel system for leaks.
* Check oxygen sensor control circuit.
* Check cold-start valve.
* Check injector fuel pressure and volume.
* Check airflow sensor lever adjustment and control plunger.
* Check throttle potentiometer.
* Check injector fuel pressure and volume.
* Check full throttle switch.
* Check mass airflow sensor (if equipped).
* Check intake air preheating system.
* Check exhaust system for leaks (between cylinder and
oxygen (O2) sensor).
* Check ignition timing.
ENGINE KNOCK
* Check knock sensors (if equipped).

H - TESTS W/O CODES
Article Text (p. 6)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
* Check full throttle switch.
* Check ignition timing.
ENGINE RUNS UNEVENLY OVER ENTIRE SPEED RANGE
* Check auxiliary air intake system.
* Check injector fuel pressure and volume.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify the problem. These procedures may lead
to the computer setting a fault code (on some systems) which may help
in diagnosis.
If problem vehicle does not produce fault codes, monitor
voltage or resistance values using a DVOM while attempting to
reproduce conditions causing intermittent fault. A status change on
DVOM indicates a fault has been located.
Use a DVOM to pinpoint faults. When monitoring voltage,
ensure ignition switch is in ON position or engine is running. Ensure
ignition switch is in OFF position or negative battery cable is
disconnected when monitoring circuit resistance. Status changes on
DVOM during test procedures indicate area of fault.
TEST PROCEDURES
Intermittent Simulation
To reproduce the conditions creating an intermittent fault,
use the following methods:
* Lightly vibrate component.
* Heat component.
* Wiggle or bend wiring harness.
* Spray component with water.
* Remove/apply vacuum source.
Monitor circuit/component voltage or resistance while
simulating intermittent. If engine is running, monitor for self-
diagnostic codes. Use the test results to identify a faulty component
or circuit. For system or component testing refer to the appropriate
I - SYS/COMP TESTS article in this section. See the menu below:
* For Cabriolet, see: I - SYSTEM/COMPONENT TESTS
* For Corrado SLC, see: I - SYSTEM/COMPONENT TESTS
* For EuroVan, see: I - SYSTEM/COMPONENT TESTS
* For Fox, see: I - SYSTEM/COMPONENT TESTS
* For Golf, GTI, Jetta, see: I - SYSTEM/COMPONENT TESTS
* For Passat GL 2.0L 4-Cylinder, see:

H - TESTS W/O CODES
Article Text (p. 7)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
I - SYSTEM/COMPONENT TESTS - 4-CYL
* For Passat GLX 2.8L VR6, see:
I - SYSTEM/COMPONENT TESTS - VR6
END OF ARTICLE

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
ARTICLE BEGINNING
GENERAL INFORMATION
Using Wiring Diagrams
All Models
INTRODUCTION
Mitchell obtains wiring diagrams and technical service
bulletins, containing wiring diagram changes from the domestic and
import manufacturers. These are checked for accuracy and are all
redrawn into a consistent format for easy use.
In the past, when cars were simpler, diagrams were simpler.
All components were connected by wires and diagrams seldom exceeded 4
pages in length. Today, some wiring diagrams require more than 16
pages. It would be impractical to expect a service technician to trace
a wire from page 1 across every page to page 16.
Removing some of the wiring maze reduces eyestrain and time
wasted searching across several pages. Today the majority of Mitchell
diagrams follow a much improved format, which permits space for
internal switch details.
Wiring diagrams are drawn in a "top-down" format. The
diagrams are drawn with the power source at the top of the diagram and
the ground point at the bottom of the diagram. Components locations
are identified on the wiring diagrams. Any wires that don't connect
directly to a component are identified on the diagram to indicate
where they go.
COLOR ABBREVIATIONS
COLOR ABBREVIATIONS TABLEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄColor Normal Optional
Black ................ BLK .......................... BK
Blue ................. BLU .......................... BU
Brown ................ BRN .......................... BN
Clear ................ CLR .......................... CR
Dark Blue .......... DK BLU ...................... DK BU
Dark Green ......... DK GRN ...................... DK GN
Green ................ GRN .......................... GN
Gray ................. GRY .......................... GY
Light Blue ......... LT BLU ...................... LT BU
Light Green ........ LT GRN ...................... LT GN
Orange ............... ORG .......................... OG
Pink ................. PNK .......................... PK
Purple ............... PPL .......................... PL
Red .................. RED .......................... RD
Tan .................. TAN .......................... TN

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 2)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
Violet ............... VIO .......................... VI
White ................ WHT .......................... WT
Yellow ............... YEL .......................... YLÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ IDENTIFYING WIRING DIAGRAM ABBREVIATIONS
NOTE: Abbreviations used on Mitchell diagrams are normally
self-explanatory. If necessary see ABBREVIATIONS
article in GENERAL INFORMATION.
IDENTIFYING WIRING DIAGRAM SYMBOLS
NOTE: Standard wiring symbol are used in Mitchell diagrams. The
illustration below will help clarify any symbols that are
not easily understood at a glance. Most components are
labeled "Motor", "Switch" or "Relay" in addition to being
drawn with the standard symbol.

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 3)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PMFig. 1: Identifying Wiring Diagram Symbols
WIRING DIAGRAM COMPONENT LOCATIONS

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 4)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
When trying to locate a component in a wiring diagram and you
don't know the specific system where it is located, use this handy
component locator to find the system wiring diagram in which the
component is located. Then, go to that system and locate the component
within the wiring diagram.
For example, if you don't know the specific system in which
the ignition switch is located, look up ignition switch in the wiring
diagram component location tables and go to the appropriate wiring
diagram(s) which contain either full or partial views of the ignition
switch. The full view of the ignition switch is located in Power
Distribution.
The first listing for the component will be the full or most
complete view of the component. Additional listings will be partial
views of the component. Not all components are used on all models.
All components will have a partial view in Ground
Distribution and Power Distribution. Data Link Connectors show
connecting circuits between modules. Alternate names for components
may be listed in wiring diagram component locations tables.
WIRING DIAGRAM COMPONENT LOCATIONS TABLEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄComponent Wiring Diagram
ABS Electronic Control Unit ....................... Anti-Lock Brakes
Data Link Connectors
ABS Hydraulic Unit ................................ Anti-Lock Brakes
Acceleration Sensor ............................... Anti-Lock Brakes
Accessory Delay Relay ................................ Power Windows
A/C Compressor Clutch Relay ..................... Engine Performance
A/C Sensor ...................................... Engine Performance
A/C Pressure Switch ............................. Engine Performance
Adaptive Lamp Control Module ....................... Exterior Lights
Air Bag(s) ................................ Air Bag Restraint System
Air Bag Module ............................ Air Bag Restraint System
Air Bag Sensor(s) ......................... Air Bag Restraint System
Air Injection Pump Relay ........................ Engine Performance
Air Temperature Sensor ............................ Overhead Console
Alternator (Generator) ..................... Generators & Regulators
Anti-Theft Control Module ........................ Anti-Theft System
Starters
Autolamp Control Relay ........................... Headlight Systems
Daytime Running Lights
Automatic Shutdown (ASD) Relay .................. Engine Performance
Generators & Regulators
Autostick Switch ................................ Engine Performance
Auxiliary Battery Relay .................... Generators & Regulators
Back-Up Lights ...................................... Back-Up Lights
Exterior Lights
Barometric (BARO) Pressure Sensor ............... Engine Performance
Battery ......................................... Power Distribution
Battery Temperature Sensor ...................... Engine Performance

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 5)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
Body Control Module .......................... Body Control Computer
Anti-Theft System
Daytime Running Lights
Engine Performance
Headlight Systems
Warning Systems
Boost Control Solenoid .......................... Engine Performance
Boost Sensor .................................... Engine Performance
Brake Fluid Level Switch .................. Analog Instrument Panels
Brake On/Off (BOO) Switch ................... Cruise Control Systems
Engine Performance
Shift Interlock Systems
Buzzer Module ...................................... Warning Systems
Camshaft Position (CMP) Sensor .................. Engine Performance
Central Control Module ........................... Anti-Theft System
Clockspring ............................... Air Bag Restraint System
Cruise Control Systems
Steering Column Switches
Clutch Pedal Position Switch .............................. Starters
Clutch Start Switch ....................................... Starters
Combination Meter ......................... Analog Instrument Panels
Constant Control Relay Module (CCRM) ............ Engine Performance
Electric Cooling Fans
Convenience Center .............................. Power Distribution
Illumination/Interior Lights
Convertible Top Motor ........................ Power Convertible Top
Convertible Top Switch ....................... Power Convertible Top
Crankshaft Position (CKP) Sensor ................ Engine Performance
Cruise Control Module ....................... Cruise Control Systems
Cruise Control Switch ....................... Cruise Control Systems
Condenser Fan Relay(s) ....................... Electric Cooling Fans
Data Link Connector (DLC) ....................... Engine Performance
Daytime Running Lights Module ............... Daytime Running Lights
Exterior Lights
Defogger Relay ................................ Rear Window Defogger
Diagnostic Energy Reserve Module (DERM) ... Air Bag Restraint System
Discriminating Sensor (Air Bag) ........... Air Bag Restraint System
Distributor ..................................... Engine Performance
Door Lock Actuators ............................... Power Door Locks
Remote Keyless Entry
Door Lock Relay(s) ................................ Power Door Locks
Electrochromic Mirror ................................ Power Mirrors
Electronic Level Control (ELC)
Height Sensor .............................. Electronic Suspension
Electronic Level Control (ELC) Module ........ Electronic Suspension
Engine Coolant Temperature (ECT)
Sending Unit ............................ Analog Instrument Panels
Engine Coolant Temperature (ECT) Sensor ......... Engine Performance
Engine Control Module ........................... Engine Performance
Generators & Regulators
Starters
ETACS ECU .......................................... Warning Systems

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 6)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
Power Windows
Remote Keyless Entry
Evaporative (EVAP) Emissions Canister ........... Engine Performance
EVAP Canister Purge Solenoid .................... Engine Performance
EVAP Canister Vent Solenoid ..................... Engine Performance
Exhaust Gas Recirculation (EGR) Valve ........... Engine Performance
Fuel Tank Vacuum Sensor ......................... Engine Performance
Fog Lights ....................................... Headlight Systems
Daytime Running Lights
Fog Light Relay .................................. Headlight Systems
Daytime Running Lights
Fuel Door Release Solenoid ................. Power Fuel Door Release
Fuel Gauge Sending Unit ................... Analog Instrument Panels
Fuel Injectors .................................. Engine Performance
Fuel Pump ....................................... Engine Performance
Fuel Pump Relay ................................. Engine Performance
Power Distribution
Fuse/Relay Block ................................ Power Distribution
Fusible Links ................................... Power Distribution
Generators & Regulators
Starters
Generator .................................. Generators & Regulators
Engine Performance
Power Distribution
Generic Electronic Module (GEM) ............... Body Control Modules
Electronic Suspension
Glow Plug Relay ................................. Engine Performance
Glow Plugs ...................................... Engine Performance
Grounds ........................................ Ground Distribution
Headlight Door Module .............................. Headlight Doors
Headlight Relay .................................. Headlight Systems
Daytime Running Lights
Headlights ....................................... Headlight Systems
Daytime Running Lights
Heated Oxygen Sensor(s) (HO2S) .................. Engine Performance
Heated Windshield Control Module ................ Heated Windshields
Height Sensor ................................ Electronic Suspension
Horns ..................................... Steering Column Switches
Horn Relay ................................ Steering Column Switches
Idle Air Control (IAC) Motor/Valve .............. Engine Performance
Ignition Coil(s) ................................ Engine Performance
Ignition Key Lock Cylinder ....................... Anti-Theft System
Ignition Module ................................. Engine Performance
Ignition Switch ................................. Power Distribution
Engine Performance
Generators & Regulators
Starters
Illuminated Entry Module .............. Illumination/Interior Lights
Illumination Lights ................... Illumination/Interior Lights
Impact Sensor ............................. Air Bag Restraint System
Inertia Fuel Shutoff Switch ..................... Engine Performance
Inhibit Relay ............................................. Starters

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 7)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
Instrument Cluster ........................ Analog Instrument Panels
Intake Air Temperature (IAT) Sensor ............. Engine Performance
Interior Lights ....................... Illumination/Interior Lights
Interlock Switch .......................................... Starters
Junction Block .................................. Power Distribution
Keyless Entry Receiver ........................ Remote Keyless Entry
Key Reminder Switch ....................................... Starters
Knock Sensor .................................... Engine Performance
Lamp Control Module ................................ Exterior Lights
License Plate Lamp ................................. Exterior Lights
Lighting Control Module ................... Lighting Control Modules
Anti-Theft System
Daytime Running Lights
Headlight Systems
Lower Relay .................................. Power Convertible Top
Malfunction Indicator Light (MIL) ............... Engine Performance
Instrument Panels
Manifold Absolute Pressure (MAP) Sensor ......... Engine Performance
Mass Airflow (MAF) Sensor ....................... Engine Performance
Mega Fuse .................................. Generators & Regulators
Memory Seat/Mirror Module ........................... Memory Systems
Mirror Defogger ............................... Rear Window Defogger
Moon Roof Motor .................................... Power Moon Roof
Moon Roof Relay .................................... Power Moon Roof
Multi-Function Control Module ...................... Warning Systems
Neutral Safety Switch ..................................... Starters
Oil Level Switch ................................ Engine Performance
Oil Pressure Switch/Sending Unit .......... Analog Instrument Panels
Engine Performance
Overhead Console .................................. Overhead Console
Oxygen Sensor(s) (O2S) .......................... Engine Performance
Parking Brake Switch ...................... Analog Instrument Panels
Park Lights ........................................ Exterior Lights
Park/Neutral Position Switch .............................. Starters
Engine Performance
Anti-Theft System
Body Control Module
Perimeter Lighting Control Relay ................... Exterior Lights
Power Amplifier ..................................... Power Antennas
Power Antenna Module ................................ Power Antennas
Power Antenna Motor ................................. Power Antennas
Power Distribution Center ....................... Power Distribution
Generators & Regulators
Starters
Power Door Lock Motors ............................ Power Door Locks
Power Mirror Motors .................................. Power Mirrors
Memory Systems
Power Sliding Door Controller .............. Power Sliding Side Door
Power Seat Motors ...................................... Power Seats
Memory Systems
Power Steering Pressure Switch .................. Engine Performance
Power Top Motor .............................. Power Convertible Top