relay VOLKSWAGEN CORRADO 1993 User Guide

2.8L IN-LINE V6 (VR6)
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 08:47PM
ADJUSTMENTS
HYDRAULIC LIFTER TEST
To determine weak or noisy lifter, position camshaft lobe
high point upward. Using a piece of wood, push lifter down. See
Fig. 2. If lifter moves down more than .004" (.10 mm), replace lifter.
If lifter moves less than .004" (.10 mm), lifter is okay. Repeat
procedure for remaining lifters.
CAUTION: If lifter is replaced, allow 30 minutes for lifter to bleed
down before starting engine.Fig. 2: Measuring Lifter Clearance
Courtesy of Volkswagen United States, Inc.
REMOVAL & INSTALLATION
FUEL PRESSURE RELEASE
Remove fuel pump relay. Fuel pump relay is the lower right
relay located in fuse/relay panel. Crank engine for 5 seconds.
Reinstall fuel pump relay.
ENGINE
NOTE: Engine is removed with transaxle attached.
Removal
1) Obtain radio code. Turn ignition off and wait 20 seconds.
Disconnect negative battery cable. Remove air cleaner assembly.
Install 8.0 mm bolt in belt tensioner hole and remove service belt.
See Fig. 3.
2) On manual transmission models, disconnect clutch slave
cylinder. On all models, remove power steering pump and attach to
body. Remove radiator, front lock support and front bumper. Drain

A/C SYSTEM GENERAL DIAGNOSTIC PROCEDURES
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 08:48PM
* Restricted air inlet.
* Mode doors binding.
* Blower motor inoperative.
* Temperature above system capacity.
HEATING GENERAL TROUBLE SHOOTING
CONDITION & POSSIBLE CAUSE
Insufficient, Erratic, or No Heat
* Low coolant level.
* Incorrect thermostat.
* Restricted coolant flow through heater core.
* Heater hoses plugged.
* Misadjusted control cable.
* Sticking heater control valve.
* Vacuum hose leaking.
* Vacuum hose blocked.
* Vacuum motors inoperative.
* Blocked air inlet.
* Inoperative heater blower motor.
* Oil residue on heater core fins.
* Dirt on heater core fins.
Too Much Heat
* Improperly adjusted cables.
* Sticking heater control valve.
* No vacuum to heater control valve.
* Temperature door stuck open.
Airflow Changes During Acceleration
* Vacuum system leak.
* Bad check valve or reservoir.
Air From Defroster At All Times
* Vacuum system leak.
* Improperly adjusted control cables.
* Inoperative vacuum motor.
Blower Does Not Operate Correctly
* Blown fuse.
* Blower motor windings open.
* Resistors burned out.
* Motor ground connection loose.
* Wiring harness connections loose.
* Blower motor switch inoperative.
* Blower relay inoperative.
* Fan binding or foreign object in housing.
* Fan blades broken or bent.
END OF ARTICLE

ABBREVIATIONS
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 08:49PM³DDD ³Dual Diaphragm Distributor ³
³DERM
³Diagnostic Energy Reserve Module ³
³DFI
³Digital Fuel Injection ³
³DIC
³Driver Information Center ³
³DIS
³Direct Ignition System ³
³DIS
³Distributorless Ignition System ³
³DIST
³Distribution ³
³DISTR
³Distributor ³
³DK BLU
³Dark Blue ³
³DK GRN
³Dark Green ³
³DME
³Digital Motor Electronics (Motronic System) ³
³DOHC
³Double Overhead Cam ³
³DOT
³Department of Transportation ³
³DP
³Dashpot ³
³DRB-II
³Diagnostic Readout Box ³
³DVOM
³Digital Volt/Ohm Meter (see VOM) ³
³Def.
³Defogger or Defroster ³
³Def.
³Defrost ³
³Defog.
³Defogger ³
³Diag.
³Diagnostic ³
³Dist.
³Distributor or Distribution ³
³Dr.
³Door ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ "E" ABBREVIATION TABLE
"E" ABBREVIATION TABLE
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ABBREVIATION
³DEFINITION ³
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³EAC
³Electric Assist Choke ³
³EACV
³Electric Air Control Valve ³
³EBCM
³Electronic Brake Control Module ³
³ECA
³Electronic Control Assembly ³
³ECAT
³Electronically Controlled Automatic Transaxle ³
³ECM
³Electronic Control Module ³
³ECT
³Engine Coolant Temperature Sensor ³
³ECU
³Electronic Control Unit or Engine Control Unit ³
³EDF
³Electric Drive Fan relay assembly ³
³EDIS
³Electronic Distributorless Ignition System ³
³EEC
³Electronic Engine Control ³
³EECS
³Evaporative Emission Control System ³
³EEPROM
³Electronically Erasable PROM ³
³EFE
³Early Fuel Evaporation ³
³EFI
³Electronic Fuel Injection ³
³EGO
³Exhaust Gas Oxygen sensor (see HEGO) ³
³EGR
³Exhaust Gas Recirculation system ³
³EGRC
³EGR Control solenoid or system ³
³EGRV
³EGR Vent solenoid or system ³
³EMR
³Emission Maintenance Reminder Module ³
³ESA
³Electronic Spark Advance ³
³ESC
³Electronic Spark Control ³

ABBREVIATIONS
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 08:49PM
"H" ABBREVIATION TABLEÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ABBREVIATION
³DEFINITION ³
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³H/D
³Heavy Duty ³
³HAC
³High Altitude Compensation ³
³HC
³Hydrocarbons ³
³HEDF
³High Speed Electro Drive Fan relay or circuit ³
³HEGO
³Heated Exhaust Gas Oxygen Sensor ³
³HEGOG
³HEGO Ground circuit ³
³HEI
³High Energy Ignition ³
³HLDT
³Headlight ³
³HO
³High Output ³
³HP
³High Performance ³
³HSC
³High Swirl Combustion ³
³HSO
³High Specific Output ³
³HTR
³Heater ³
³HVAC
³Heating ³
³Headlt.
³Headlight ³
³Hg
³Mercury ³
³Hgt.
³Height ³
³Htr.
³Heater ³
³Hz
³Hertz (Cycles Per Second) ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ "I" ABBREVIATION TABLE
"I" ABBREVIATION TABLE
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ABBREVIATION
³DEFINITION ³
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³I.D.
³Inside Diameter ³
³IAC
³Idle Air Control ³
³IACV
³Idle Air Control Valve ³
³IC
³Integrated Circuit ³
³ID
³Identification ³
³IDM
³Ignition Diagnostic Monitor ³
³IGN
³Ignition system or circuit ³
³ILC
³Idle Load Compensator ³
³In. Hg
³Inches of Mercury ³
³INCH Lbs.
³Inch Pounds ³
³INFL REST
³Inflatable Restraint ³
³INJ
³Injector or Injection ³
³IP
³Instrument Panel ³
³IPC
³Instrument Panel Cluster ³
³ISA
³Idle Speed Actuator ³
³ISC
³Idle Speed Control ³
³ISS
³Idle Stop Solenoid ³
³ITS
³Idle Tracking Switch ³
³IVSV
³Idle Vacuum Switching Valve ³
³Ign.
³Ignition ³
³In.
³Inches ³

ABBREVIATIONS
Article Text (p. 10)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 08:49PM
"Q" ABBREVIATION TABLE
"Q" ABBREVIATION TABLEÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ABBREVIATION
³DEFINITION ³
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³Qts.
³Quarts ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ "R" ABBREVIATION TABLE
"R" ABBREVIATION TABLE
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ABBREVIATION
³DEFINITION ³
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³RABS
³Rear Anti-Lock Brake System ³
³RAC
³Remote Accessory Control ³
³RAM
³Random Access Memory ³
³RAP
³Retained Accessory Power ³
³RECIRC
³Recirculation ³
³RED
³Red ³
³RH
³Right Hand ³
³ROM
³Read Only Memory ³
³RPM
³Revolutions Per Minute ³
³RVB
³Rear Vacuum Break ³
³RWAL
³Rear Wheel Anti-Lock Brake ³
³RWD
³Rear Wheel Drive ³
³Recirc.
³Recirculate or Recirculation ³
³Reg.
³Regulator ³
³Rly.
³Relay ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ "S" ABBREVIATION TABLE
"S" ABBREVIATION TABLE
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ABBREVIATION
³DEFINITION ³
ÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³SBC
³Single Bed Converter ³
³SBEC
³Single Board Engine Controller ³
³SC
³Super Charged ³
³SCC
³Spark Control Computer ³
³SCS
³Air Suction Control Solenoid ³
³SDM
³Supplemental Restraint System Diagnostic Module ³
³SDU
³SRS Diagnostic Unit ³
³SEN
³Sensor ³
³SES
³Service Engine Soon ³
³SFI
³Sequential (Port) Fuel Injection ³
³SIG RTN
³Signal Return circuit ³
³SIL
³Shift Indicator Light ³

ANTI-LOCK BRAKE SYSTEM
Article Text
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 08:57PM
ARTICLE BEGINNING
1993 BRAKES
Volkswagen Anti-Lock
Corrado SLC
ANTI-LOCK BRAKE SAFETY PRECAUTIONS
* NEVER open a bleeder valve or loosen a hydraulic line while
ABS is pressurized
* NEVER disconnect or reconnect any electrical connectors while
ignition is on. Damage to ABS control unit may result.
* DO NOT attempt to bleed hydraulic system without first
referring to the appropriate article.
* Only use specially designed brake hoses/lines on ABS-equipped
vehicles.
* DO NOT tap on speed sensor components (sensor, sensor rings).
Speed rings must be pressed, NOT hammered into hubs. Striking
these components can cause demagnetization or a loss of
polarization, affecting the accuracy of the speed signal
returning to the ABS control unit.
* DO NOT mix tire sizes. Increasing the width, as long as tires
remain close to the original diameter, is acceptable. Rolling
diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* DO NOT contaminate speed sensor components with grease. Only
use recommended anti-corrosion coating.
* When speed sensor components have been removed, ALWAYS check
sensor-to-ring air gaps when applicable. These specifications
can be found in each appropriate article.
* ONLY use recommended brake fluids. DO NOT use silicone brake
fluids in an ABS-equipped vehicle.
* When installing transmitting devices (CB's, telephones, etc.)
on ABS-equipped vehicles, DO NOT locate the antenna near the
ABS control unit (or any control unit).
* Disconnect all on-board computers, when using electric
welding equipment.
* DO NOT expose the ABS control unit to prolonged periods of
high heat (185øF/85øC for 2 hours is generally considered a
maximum limit).
DESCRIPTION
A Teves Anti-Lock Brake System (ABS) is used. See Fig. 1.
This system reduces the chance of wheel lock-up during heavy braking.
The system consists of 4 wheel speed sensors, Electronic Control Unit
(ECU), hydraulic modulator/pump and solenoid valves, ANTILOCK and
BRAKE warning lights. There are 2 relays located at fuse/relay panel,

ANTI-LOCK BRAKE SYSTEM
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 08:57PM
HYDRAULIC MODULATOR/PUMP
Depressurize brake system. See DEPRESSURIZING BRAKE SYSTEM.
Turn ignition on. Hydraulic modulator/pump should operate for 60
seconds maximum and then stop. Depress brake pedal a few times; pump
should operate again for a few seconds. If pump motor does not
operate, check electrical system. If pump motor operates for more than
60 seconds, internal or external hydraulic leak may be indicated.
Check for external leaks. If external leak is not found, further
testing may be needed to check for internal leaks.
ANTILOCK WARNING LIGHT
Start engine. ANTILOCK warning light should come on, then
turn off after a few seconds. If light does not come on when engine is
started, check electrical system. If light comes on and stays on,
fault has been detected by the ECU and testing will be needed. See
SYSTEM TESTING under DIAGNOSIS & TESTING.
DIAGNOSIS & TESTING
SYSTEM TESTING
NOTE: Check battery condition, brake fluid level, electrical
connections and wiring for damage. If fluid level is
incorrect or battery and/or electrical connections are
faulty, correct problem before preceding. Perform each step,
in sequence, to test entire system, except for ECU. If
faulty ECU is suspected, replace with a known good one, and
retest system. Unplug ECU connector for all test steps.
Power-To-ECU Test
Turn ignition off. Unplug ECU connector. Turn ignition on.
Using a voltmeter, check voltage between ECU connector terminals No. 1
and 2. See Fig. 2. If voltage is 10 volts or more, go to next test. If
voltage is less than 10 volts, check battery, ground, ABS fuse, relay
and wiring. Repair as necessary.Fig. 2: Identifying ECU Connector Terminals
Courtesy of Volkswagen United States, Inc.
ECU Relay Voltage Test
Connect a jumper wire between ECU connector terminals No. 2
and 8. See Fig. 2. Turn ignition on. Using a voltmeter, check voltage
between ECU connector terminals No. 1 and 3. If voltage is 10 volts or
more, go to next test. If voltage is less than 10 volts, check ABS

ANTI-LOCK BRAKE SYSTEM
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 08:57PM
fuse. If fuse is faulty, replace and retest. If fuse is okay, check
wiring. If wiring is faulty, repair and retest. If wiring is okay,
replace relay and retest.
Brakelight Switch
Turn ignition on. Apply brakes. Check for 12 volts between
terminals No. 12 and 1. If 12 volts are present, brakelight switch is
okay. If 12 volts are not present, check fuse, brakelight switch and
Black/Red wire from brakelight switch to ECU.
Hydraulic Modulator/Pump Relay Voltage Test
1) Turn ignition off. Unplug hydraulic modulator/pump
connector. Depress brake pedal 25 times. Turn ignition on. Using a
voltmeter, measure voltage between ECU connector terminals No. 1 and
32. See Fig. 2. If voltage is 10 volts or more, go to RIGHT REAR WHEEL
SPEED SENSOR VOLTAGE TEST under SYSTEM TESTING.
2) If voltage is less than 10 volts, check hydraulic
modulator/pump fuse. If fuse is okay, check wiring between ECU
connector terminal No. 32 and hydraulic modulator/pump connector
terminal No. 1 (large gauge Red/Black wire). See Figs. 2 and 4. If
wiring is not okay, repair wiring, and retest. If wiring is okay,
replace relay, and retest.
Right Rear Wheel Speed Sensor Voltage Test
Connect an AC voltmeter between ECU connector terminals No. 4
and 22. See Fig. 2. Rotate right rear wheel at one revolution per
second. Measure voltage with wheel rotating. If voltage is 0.075 volt
or more, go to next test. If voltage is less than 0.075 volt, check
wheel speed sensor and/or toothed ring for damage, wear and proper
installation. If damage or wear is found, replace faulty component and
retest. If components are not properly installed, reposition and
retest. If components are okay, replace wheel speed sensor and retest.
Left Rear Wheel Speed Sensor Voltage Test
Connect an AC voltmeter between ECU connector terminals No. 6
and 24. See Fig. 2. Rotate left rear wheel at one revolution per
second. Measure voltage with wheel rotating. If voltage is 0.075 volt
or more, go to next test. If voltage is less than 0.075 volt, check
wheel speed sensor and/or toothed ring for damage, wear and proper
installation. If damage or wear is found, replace faulty component and
retest. If components are not properly installed, reposition and
retest. If components are okay, replace wheel speed sensor and retest.
Right Front Wheel Speed Sensor Voltage Test
Connect an AC voltmeter between ECU connector terminals No. 7
and 25. See Fig. 2. Rotate right front wheel at one revolution per
second. Measure voltage with wheel rotating. If voltage is 0.075 volt
or more, go to next test. If voltage is less than 0.075 volt, check
wheel speed sensor and/or toothed ring for damage, wear and improper
installation. If damage or wear is found, replace faulty component,
and retest. If components are improperly installed, reposition
component, and retest. If components are okay, replace wheel speed

ANTI-LOCK BRAKE SYSTEM
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 08:57PM
sensor, and retest.
Left Front Wheel Speed Sensor Voltage Test
Connect an AC voltmeter between ECU connector terminals No. 5
and 23. See Fig. 2. Rotate left front wheel at one revolution per
second. Measure voltage with wheel rotating. If voltage is 0.075 volt
or more, go to next test. If voltage is less than 0.075 volt, check
wheel speed sensor and/or toothed ring for damage, wear and proper
installation. If damage or wear is found, replace faulty component and
retest. If components are not properly installed, reposition and
retest. If components are okay, replace wheel speed sensor and retest.
ECU Relay Continuity Test
Turn ignition off. Using an ohmmeter, check for continuity
between ECU connector terminals No. 1 and 3, and between terminals No.
1 and 20. See Fig. 2. If there is continuity at both test points, go
to next test. If there is no continuity at either or both test points,
check wiring. If wiring is faulty, repair and retest. If wiring is
okay, replace relay and retest.
Solenoid Valves Ground Circuit Continuity Test
1) Turn ignition off. Remove jumper wire from previous test.
Using an ohmmeter, check for continuity between ECU connector
terminals No. 1 and 11. See Fig. 2. If there is continuity, go to step
3).
2) If continuity does not exist, check for continuity between
ECU connector terminal No. 1 and valve block housing and between
hydraulic modulator and valve block housing. If continuity does not
exist between ECU connector terminal No. 1 and valve block housing,
repair wiring, and retest. If continuity does not exist between
housings, repair as necessary.
3) Reconnect jumper wire between ECU connector terminals No.
1 and 11. Check for continuity between ECU connector terminal No. 11
and valve block connector terminal No. 1 (Brown wire). See Figs. 2 and
4. If there is no continuity, repair wiring and retest.
Hydraulic Modulator/Pump Relay Ground Circuit Test
Turn ignition off. Reconnect pressure switch connector.
Depress brake pedal 20 times. Using an ohmmeter, check for continuity
between ECU connector terminals No. 1 and 14. If continuity exists, go
to next test. If continuity does not exist, check for continuity
between pressure switch terminals No. 1 (Brown wire) and No. 4
(Red/Yellow or White wire). See Figs. 1 and 4. If continuity does not
exist, replace pressure switch, and retest. If continuity exists,
check wiring between ECU terminal No. 14 and pressure switch terminal
No. 4. Repair wiring, and retest.
Low Pressure Warning Switch Test
Turn ignition off. Ensure brake fluid level is okay and fluid
level sensor switch float is in correct position (switch is in closed
position). Ensure accumulator is fully charged and pump is not
operating. Using an ohmmeter, check for continuity between ECU

ANTI-LOCK BRAKE SYSTEM
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 08:57PM
terminals No. 1 and 7. See Fig. 2. If resistance is 20,000 ohms or
more, go to next test. If resistance is less than 20,000 ohms, check
shielding wire for damage. Replace harness if damaged, and retest.
Left Front Wheel Speed Sensor Shielding Resistance Test
Using an ohmmeter, measure resistance between ECU connector
terminals No. 1 and 5. See Fig. 2. If resistance is 20,000 ohms or
more, go to next test. If resistance is less than 20,000 ohms, check
shielding wire for damage. Replace harness if damaged, and retest.
ECU Relay Resistance Test
Using an ohmmeter, measure resistance between ECU connector
terminals No. 1 and 8. See Fig. 2. If resistance is 50-100 ohms, go to
next test. If resistance is not as specified, check wiring. If wiring
is faulty, repair and retest. If wiring is okay, replace relay and
retest. See Fig. 3.Fig. 3: Locating Relays
Courtesy of Volkswagen United States, Inc.
ABS Main Valve Resistance Test
Using an ohmmeter, measure resistance between terminals at
ABS main valve terminals. See Figs. 1 and 4. If resistance is 2-5
ohms, ABS main valve is okay. If resistance is not 2-5 ohms, replace
hydraulic modulator.