VOLKSWAGEN CORRADO 1993 Repair Manual

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 8)
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 Top Relay(s) ........................... Power Convertible Top
Powertrain Control Module ....................... Engine Performance
Analog Instrument Panels
Cruise Control Systems
Data Link Connectors
Generators & Regulators
Starters
Power Window Motors .................................. Power Windows
Power Window Relay(s) ................................ Power Windows
Radiator Fan Motor(s) ........................ Electric Cooling Fans
Radiator Fan Relay(s) ........................... Engine Performance
Electric Cooling Fans
Rainsense Module .............................. Wiper/Washer Systems
Raise Relay .................................. Power Convertible Top
Remote Anti-Theft Personality (RAP) Module ....... Anti-Theft System
Starters
Warning Systems
Seat Belt Pretensioners ................... Air Bag Restraint System
Seat Belt Retractor Solenoid .................... Passive Restraints
Seat Belt Switch .......................... Air Bag Restraint System
Passive Restraints
Shift Interlock Solenoid ................... Shift Interlock Systems
Shift Lock Actuator ........................ Shift Interlock Systems
Side Marker Lights ................................. Exterior Lights
SIR Coil Assembly (Clockspring) ........... Air Bag Restraint System
Slip Ring (Clockspring) ................... Air Bag Restraint System
Steering Column Switches
SRS Control Module ........................ Air Bag Restraint System
Starter Motor ............................................. Starters
Starter Interrupt Relay ................................... Starters
Starter Solenoid .......................................... Starters
Starter Relay ............................................. Starters
Steering Wheel Position Sensor .................... Anti-Lock Brakes
Stoplights ......................................... Exterior Lights
Stoplight Switch ................................ Engine Performance
Cruise Control Systems
Anti-Lock Brakes
Sun Roof ECU ........................................ Power Sun Roof
Sun Roof Motor ...................................... Power Sun Roof
Sun Roof Position Sensor ............................ Power Sun Roof
Taillights ......................................... Exterior Lights
Throttle Position (TP) Sensor ................... Engine Performance
Torque Converter Clutch Solenoid/Switch ......... Engine Performance
Traction Control Switch ........................... Anti-Lock Brakes
Trailer Tow Connector .............................. Exterior Lights
Trailer Tow Relay .................................. Exterior Lights
Transmission/Transaxle .......................... Engine Performance
Transmission Control Module (TCM) ............... Engine Performance
Starters
Transmission Range Sensor ................................. Starters
Back-Up Lights
Engine Performance

HOW TO USE SYSTEM WIRING DIAGRAMS
Article Text (p. 9)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
Transmission Range Switch ........................... Back-Up Lights
Engine Performance
Anti-Theft System
Turn Signal Flasher ................................ Exterior Lights
Turn Signal Lights ................................. Exterior Lights
Twilight Sentinel Switch ......................... Headlight Systems
Daytime Running Lights
Vapor Canister Leak Detection Pump .............. Engine Performance
Vehicle Control Module (VCM) .................... Engine Performance
Vehicle Dynamic Module ....................... Electronic Suspension
Vehicle Speed Control Servo ................. Cruise Control Systems
Vehicle Speed Sensor .......................... Data Link Connectors
Analog Instrument Panels
Cruise Control Systems
Electronic Suspension
Voltage Regulator .......................... Generators & Regulators
Water-In-Fuel Sensor ............................ Engine Performance
Analog Instrument Panels
Wheel Speed Sensors ............................... Anti-Lock Brakes
Window Timer Module .......................... Power Convertible Top
Windshield Intermittent Wiper Relay ........... Wiper/Washer Systems
Windshield Washer Motor ....................... Wiper/Washer Systems
Wiper Motor ................................... Wiper/Washer SystemsÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄEND OF ARTICLE

I - SYSTEM/COMPONENT TESTS
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
1993 ENGINE PERFORMANCE
System & Component Testing - Motronic
Corrado SLC
INTRODUCTION
Since many computer-controlled and monitored components set a
trouble code if they malfunction, also perform test procedures in the
G - TESTS W/CODES article. In most instances, Scan Tester (VAG 1551)
must be used to test systems and/or components. See ENTERING SELF-
DIAGNOSTICS in the G - TESTS W/CODES article for additional scan
tester operating instructions. See Fig. 1.
COMPONENT LOCATIONSFig. 1: Component Locations (Corrado SLC)
Courtesy of Volkswagen United States, Inc.

I - SYSTEM/COMPONENT TESTS
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
COMPUTERIZED ENGINE CONTROLS
ELECTRONIC CONTROL MODULE (ECM)
Ground & Power Circuits
Check ECM ground and power circuits using the values in the
appropriate J - PIN VOLTAGE CHARTS article.
ENGINE SENSORS & SWITCHES
ENGINE COOLANT TEMPERATURE SENSOR
Corrado SLC (2.8L)
1) Ensure engine is cold. Connect Scan Tester (VAG 1551) to
Data Link Connectors (DLC) located in center console, in front of
shift lever. Start engine and allow it to idle.
2) With scan tester in READ TEST VALUE BLOCK function, select
group No. 01 and read coolant temperature value in field No. 2 of scan
tester. Temperature value must increase uniformly without
interruption. If value increases as specified, select END OUTPUT
function on scan tester.
3) If displayed value does not change or if engine
malfunctions during certain temperature ranges, turn ignition off and
measure engine coolant temperature sensor resistance. See ENGINE
COOLANT TEMPERATURE SENSOR RESISTANCE table.
ENGINE COOLANT TEMPERATURE SENSOR RESISTANCEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄTemperature
øF (øC) Ohms
68 (20) ......................... 3000-2000
86 (30) ......................... 2000-1500
104 (40) ........................ 1500-1000
122 (50) ......................... 1000-800
140 (60) .......................... 700-500
158 (70) .......................... 500-375
176 (80) .......................... 375-275
194 (90) .......................... 275-225
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ INTAKE AIR TEMPERATURE SENSOR
Corrado SLC (2.8L)
1) Turn ignition off. Disconnect intake air temperature
sensor. Remove sensor from intake manifold and plug opening in
manifold. Reconnect sensor to wiring harness.
2) Connect Scan Tester (VAG 1551) to Data Link Connectors
(DLC) located in center console, in front of shift lever. Start engine
and allow it to idle. With scan tester in READ TEST VALUE BLOCK
function, select group 03 and read intake air temperature sensor value
in field No. 4 of scan tester.
3) Spray sensor with cooling spray and observe value on scan

I - SYSTEM/COMPONENT TESTS
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 09:11PM
tester. Scan tester value must decrease. If temperature value does not
change, repair intake air temperature sensor circuit or replace sensor
as necessary. After repairs, erase Diagnostic Trouble Code (DTC)
memory (if applicable) and select END OUTPUT function.
HALL EFFECT SENSOR
Corrado SLC (2.8L)
Testing information is not available from manufacturer. These
vehicles are equipped with a distributorless ignition system.
FUEL SYSTEM
ACCELERATION/FULL THROTTLE ENRICHMENT & DECELERATION FUEL
CUT-OFF
Corrado SLC (2.8L)
1) Ensure engine coolant temperature is at least 176øF
(80
øC). Connect Scan Tester (VAG 1551) to Data Link Connectors (DLC)
located in center console, in front of shift lever.
2) Start engine and allow it to idle. With scan tester in
READ TEST VALUE BLOCK function, select group No. 04 and read value in
field No. 4 of scan tester. Display value must be 00010 at idle.
3) Using accelerator pedal, increase engine speed to 3000 RPM
and observe scan tester. Display value in field No. 4 of scan tester
must briefly be 10100. Release accelerator pedal and observe scan
tester.
4) Display value in field No. 4 of scan tester must briefly
be 00011, then return to 00010 at idle. If values are not as
specified, see THROTTLE POSITION (TP) SENSOR ADJUSTMENT procedures in
the D - ADJUSTMENTS article. If values are as specified, select END
OUTPUT function on scan tester.
FUEL INJECTORS & CIRCUIT
Corrado SLC (2.8L)
1) To access fuel injectors, remove ignition wires. Remove
hose from mass airflow sensor. Disconnect hose to fuel evaporative
(frequency) solenoid valve at throttle body.
2) Disconnect throttle position sensor and idle air control
valve. Disconnect accelerator cable from throttle body. Disconnect and
plug coolant hoses at throttle body.
3) Disconnect hose from air intake heated tube. Detach fuel
lines at cylinder head cover and remove from fuel rail. Disconnect
vacuum hose from fuel pressure regulator. Remove intake manifold upper
section. See Fig. 2.
4) With intake manifold upper section removed, disconnect
wiring harness from fuel injectors. Using a Digital Volt-Ohmmeter
(DVOM) and test leads from Adapter Kit (VW 1594), check fuel injector
resistance. See Fig. 3.
5) Fuel injector resistance should be 15.0-21.5 ohms. If
resistance is zero ohms, check for a short circuit in wiring harness.

I - SYSTEM/COMPONENT TESTS
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
If wiring harness is okay, replace fuel injector(s).Fig. 2: Accessing Fuel Injectors (Corrado SLC)
Courtesy of Volkswagen United States, Inc.
6) With wiring harness and fuel injectors okay, disconnect
ignition coil power output stage. Using test leads from adapter kit,
check voltage supply to each injector by connecting LED tester between
wiring harness connector terminals. See Fig. 3.
7) Crank engine and observe LED tester. LED tester must
flicker. If LED tester does not flicker, reconnect wiring harness
connector(s) to fuel injector(s). Check wiring harness for an open
circuit between fuel injector(s) and Engine Control Module (ECM).
8) If LED tester flickers, remove fuel rail assembly (leaving
fuel lines and injectors attached). Use test leads and fuel rail hose
extensions if necessary. Disconnect Blue Engine Coolant Temperature
(ECT) sensor. Connect the 15,000 ohm side of Adapter (VAG 1490)
directly to ECT sensor wiring harness connector.
9) Place injectors in Fuel Analyzer (VAG 1602). Crank engine
and observe injectors. Injector spray pattern must be the same for all
injectors. Turn ignition on for 5 seconds and check fuel injectors for
leaks. No more than 2 drops are permissible per minute. When

I - SYSTEM/COMPONENT TESTS
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
reinstalling fuel rail, ensure that "O" rings are not damaged.Fig. 3: Testing Fuel Injectors & Circuit (Corrado SLC)
Courtesy of Volkswagen United States, Inc.
OXYGEN SENSOR CONTROL
IDLE CONTROL SYSTEM
IDLE AIR CONTROL (IAC) VALVE
Corrado SLC (2.8L)
1) Connect Scan Tester (VAG 1551) to Data Link Connectors
(DLC) located in center console, in front of shift lever. With scan
tester in OUTPUT DIAGNOSTIC TEST MODE, test IAC valve. For more
information, see the G - TESTS W/CODES article in this section.
2) To check IAC valve triggering circuit, turn ignition off.
Disconnect wiring harness connector from idle air control valve.
Connect LED Tester (US 1115) to wiring harness connector terminals No.
1 and 2.
3) Turn ignition on. Perform OUTPUT DIAGNOSTIC TEST MODE
until IAC valve is triggered. LED tester must flash. If LED tester
does not flash, check IAC valve circuit.
4) If LED tester flashes, disconnect wiring harness connector
from idle air control valve. Using Test Leads from Adapter Kit (VW
1594), connect DVOM to IAC valve terminals No. 1 and 2. IAC valve
resistance must be 10-20 ohms. If resistance is incorrect, replace IAC
valve.
IGNITION SYSTEM
NOTE: Ignition system testing information is not available
from manufacturer. These vehicles are equipped with a
distributorless ignition system.

I - SYSTEM/COMPONENT TESTS
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
IGNITION COIL
EMISSION SYSTEMS & SUB-SYSTEMS
NOTE: Other than EGR system, additional emission systems and
sub-system component testing information is not available
from manufacturer.
EXHAUST GAS RECIRCULATION (EGR)
Corrado SLC (2.8L)
1) Ensure engine coolant temperature is at least 122øF
(50
øC). Start engine and allow it to idle. Disconnect vacuum hose from
EGR valve. See Fig. 4. Connect hand-held vacuum pump to EGR valve and
apply vacuum.
2) Idle quality must noticeably deteriorate. If idle quality
does not change, check EGR valve and exhaust manifold for plugging.
Replace EGR valve if necessary. After repairs, erase DTC memory.Fig. 4: Testing EGR System (Corrado SLC)
Courtesy of Volkswagen United States, Inc.

I - SYSTEM/COMPONENT TESTS
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
END OF ARTICLE

INSTRUMENT PANEL
Article Text
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:12PM
ARTICLE BEGINNING
1993 ACCESSORIES & EQUIPMENT
Volkswagen Instrument Panel
Corrado SLC
DESCRIPTION & OPERATION
Instrument cluster for most models includes speedometer, fuel
gauge and temperature gauge. Optional instruments include clock,
tachometer, voltmeter and oil temperature gauge. See Figs. 3.
Printed circuit provides voltage to gauges. A voltage
regulator attached to printed circuit controls voltage to fuel and
temperature gauges. Most warning lights are a Light Emitting Diode
(LED). To replace diode, pull from printed circuit socket.
TESTING
VOLTAGE REGULATOR TEST
1) If only one gauge is inoperative, regulator is not
defective. Remove instrument cluster trim. Remove combination gauge.
Connect positive (+) lead of voltmeter between combination gauge
terminals No. 1 and 2. See Fig. 1. Turn ignition on. If battery
voltage is present, go to next step. If battery voltage is not
present, repair wiring harness or replace voltage regulator as
necessary.
2) Turn ignition off. Install combination gauge. Remove
speedometer. Connect positive (+) lead of voltmeter to terminal No 1
of voltage regulator. See Fig. 2. Connect voltmeter negative (-) lead
to terminal No. 2. Turn ignition on. Meter reading should be 9.5-10.5
volts. If voltage is incorrect, replace printed circuit or voltage
regulator.Fig. 1: Testing Combination Gauge (Corrado SLC)
Courtesy of Volkswagen United States, Inc.