1993 VOLKSWAGEN CORRADO Repair Manual

F - BASIC TESTING
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 09:10PM
kg/cmý). Turn engine off. After 10 minutes, residual pressure should
be 29 psi (2 kg/cm
ý). If system pressure is too high, replace fuel
pressure regulator.
3) If residual pressure is too low, operate engine until
system pressure builds up, then pinch off Blue fuel return line. If
pressure holds, replace the fuel regulator. If fuel pressure is low,
check for leaks at fuel lines, fuel injectors and fuel pump check
valve
TRANSFER PUMP CHECK
Transfer Pump Fuel Volume Check
1) Turn ignition off. To check transfer pump (in tank),
remove rear seat. Remove fuel sending unit access cover. Disconnect
ignition coil secondary wire and jumper to ground.
2) With transmission in Neutral, crank engine for 3-4
seconds. While starter is turning and for a few seconds afterwards, an
audible sound should be heard at the pump. If sound is not heard, go
to next step. If sound is heard, go to step 5).
3) Remove fuel pump relay from relay panel. On Corrado and
Passat, activate fuel pumps using Remote Control (VAG 1348/3A). On all
other models, activate fuel pumps using Remote Control (US 4480/3). On
all models, if pump does not operate, remove transfer pump wire
harness connector. See Fig. 1.
4) Using test light, check voltage between middle wire and
outer Brown wire of fuel pump connector for Digifant fuel system, or
between Brown wire and Red/Yellow wire for CIS-E fuel system. If
voltage is present, replace transfer pump. If voltage is not present,
repair open or short circuit in wiring.
5) Remove fuel pump relay jumper wire. Disconnect and plug
transfer pump output hose. Attach a hose to pump outlet connector and
place other end of hose in a graduated container. Activate fuel pump
for 10 seconds.
6) Minimum fuel flow should be 10 ounces (.3 liter). If fuel
flow is low, check fuel tank filter for restriction. If fuel tank
filter is okay, replace transfer pump.Fig. 1: Checking Transfer Pump Fuel Volume (Typical)
Courtesy of Volkswagen United States, Inc.
MAIN FUEL PUMP VOLUME CHECK

F - BASIC TESTING
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 09:10PM
NOTE: Before testing main fuel pump, check transfer pump. See
TRANSFER PUMP CHECK.
Cabriolet, Fox, Golf & Jetta
Remove fuel pump relay from relay panel. Activate fuel pumps
using Remote Control (US 4480/3). Activate fuel pumps for 30 seconds.
Compare fuel volume with values in FUEL PUMP PERFORMANCE table.
Corrado, GTI & Passat
1) Remove fuel pump relay from relay panel. On Corrado and
Passat, activate fuel pumps using Remote Control (VAG 1348/3A). On
GTI, activate fuel pumps using Remote Control (US 4480/3). On all
models, measure voltage being applied to fuel pump when activating
with remote control. Record voltage.
2) Fuel volume is relative to voltage applied to fuel pumps.
Activate fuel pumps for 30 seconds. Compare volume with values in FUEL
PUMP PERFORMANCE table.
FUEL PUMP PERFORMANCEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Pressure Min. Vol. In 30 Sec.
Application psi (kg/cm(
ý) Pts. (L)
Cabriolet ................ 43 (3.0) ............... 1.4 (0.7)
Corrado SLC (1) .......... 58 (4.0) ....... 1.0-1.4 (0.5-0.7)
Golf, GTI & Jetta (1) .... 43 (3.0) ....... 1.0-1.4 (0.5-0.7)
EuroVan (1) .............. 43 (3.0) ....... 1.0-1.4 (0.5-0.7)
Fox (2) .................. 36 (2.5) ............... 1.4 (0.7)
Passat GL .......... (3) 87-94 (6.1-6.6) .. 1.0-1.4 (0.5-0.7)
Passat GLX (1) ........... 58 (4.0) ....... 1.0-1.4 (0.5-0.7)
(1) - Using Adapter Cable (VAG 1348/3-2) between battery positive
terminal and terminal No. 4 of fuel pump relay socket. Fuel
pump energized, with 10-12 volts at fuel pump and engine off.
(2) - Using Remove Control Switch (US 4480/3) in place of fuel
pump relay.
(3) - Briefly operate starter and ensure fuel pump runs for at
least one second. Alternate method is to disconnect
Electronic Control Module (ECM) and ground terminal No. 12
using Remove Control Switch (VAG 1348/3A).
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄREGULATED FUEL PRESSURE
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ At Idle At Idle
w/Vacuum w/o Vacuum
Application psi (kg/cm
ý) (1) psi (kg/cmý)
Cabriolet & Fox ........ 36 (2.5) .................. 43 (3.0)
Corrado SLC ............ 50 (3.5) .................. 58 (4.0)
Golf, GTI & Jetta ...... 36 (2.5) .................. 43 (3.0)

F - BASIC TESTING
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 09:10PM
EuroVan ................ 36 (2.5) .................. 43 (3.0)
Passat GL ........ (2) 87-94 (6.1-6.6) ... (3) 87-94 (6.1-6.6)
Passat GLX ............. 50 (3.5) .................. 58 (4.0)
(1) - With vacuum hose disconnected from fuel pressure regulator.
(2) - Approximately 4.3-7.2 psi (0.3-0.5 kg/cmý) below system
pressure, with differential pressure regulator disconnected.
(3) - Approximately 18.5-23.0 psi (1.3-1.6 kg/cm
ý) below system
pressure, with differential pressure regulator connected.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ IGNITION CHECKS
NOTE: Ignition checks are divided according to fuel system.
SPARK TEST
1) Using an ohmmeter, check resistance of each spark plug
wire. See HIGH TENSION WIRE RESISTANCE table. Check for a strong Blue
spark at coil wire and at each spark plug wire by holding wire
terminal 5/16" from ground while cranking engine.
2) Disconnect and inspect all related ignition system
connectors and harness. Clean or repair if necessary. If related
connectors and harness are okay, remove negative battery cable.
Disconnect secondary and primary leads from ignition coil.
3) Using ohmmeter, check primary resistance between primary
terminals of coil. Check secondary resistance between coil secondary
terminal and primary positive terminal. Replace coil if readings are
not within specifications. See IGNITION COIL RESISTANCE table.
HIGH TENSION WIRE RESISTANCE TABLE
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Ohms
Coil Wire Only .................................. (1)
Coil Wire With Connector .................. 1600-2400
Spark Plug Wire Connector ................. 4000-6000
Suppressor (2) ............................. 600-1400
(1) - Check for continuity.
(2) - Suppressor is located between ignition coil wire
and distributor cap.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ IGNITION COIL
IGNITION COIL RESISTANCE - Ohms @ 68
øF (20øC)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Primary Secondary
Cabriolet
Digifant I ........... 0.5-0.7 ......... 3000-4000

F - BASIC TESTING
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 09:10PM
Digifant II ......... 0.52-0.76 ........ 2400-3500
Corrado SLC (1) ........ ..... .............. .....
Fox
Digifant I ........... 0.5-0.7 ......... 3000-4000
Digifant II .......... 0.6-0.7 ......... 2500-3500
Golf, GTI & Jetta ..... 0.5-0.7 ......... 3000-4000
Passat GL ............. 0.6-0.8 ......... 6500-8500
Passat GLX (1) ......... ..... .............. .....
(1) - Ignition coil pack, new for 1993, is located on
left side of cylinder head. When ignition coil is
triggered, spark is supplied to 2 spark plugs at
one time. One spark plug fires during compression
stroke and the other plug fires during exhaust
stroke (waste spark). Ignition coil specifications
are not available from manufacturer.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ DISTRIBUTOR
Hall Effect Sender
1) Remove coil secondary wire and attach to ground.
Disconnect Hall Effect sender harness connector at distributor. Using
an LED Test Light (US 1115), check for voltage between outer terminals
of connector. See Figs. 2 and 3. With ignition on, light should be on.
If light is on, go to next step. If light is not on, check wiring for
short or open circuit. If wiring is okay, replace ignition control
unit.
2) Reconnect Hall Effect sender harness connector. Pull back
Hall Effect sender boot to expose contact terminals. Connect LED Test
Light (US 1115) probe to center contact and battery positive terminal.
See Fig. 2. Observe test light while cranking engine. If test light
blinks, Hall Effect sender is okay. If light does not blink, replace
Hall Effect sender.Fig. 2: Testing Hall Effect Sender (Typical)
Courtesy of Volkswagen United States, Inc.
Voltage Supply & Ground To Hall Effect Sender

F - BASIC TESTING
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 09:10PM
1) With ignition off, disconnect Hall Effect sender harness
connector. Using a voltmeter, check for voltage between outer
terminals No. 1 and No. 3. See Fig. 3. Turn ignition on. There should
be a minimum of 9 volts on vehicles with CIS-E fuel system, or 10
volts on vehicles with Digifant fuel system.
2) If there is no voltage, check for open wire between
terminal No. 3 of Hall Effect sender connector and ECU. Also check for
voltage between terminal No. 1 of Hall Effect sender and ground.
Repair open and recheck.Fig. 3: Testing Hall Effect Sender Connector (Typical)
Courtesy of Volkswagen United States, Inc.
POWER STAGE
Voltage Supply & Ground To Power Stage
1) Turn ignition off. Disconnect coil power stage harness
connector. Connect a voltmeter to terminals No. 1 and No. 3. See
Fig. 4.
2) Turn ignition on. Ensure battery voltage is present. Turn
ignition off. If voltage is not present, check for open wire from fuse
box to terminal No. 1, or open from terminal No. 3 to ground. Repair
open wire and recheck.

F - BASIC TESTING
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 09:10PMFig. 4: Testing Ignition Coil Power Stage (Typical)
Courtesy of Volkswagen United States, Inc.
HALL CONTROL UNIT
Cabriolet, Fox, Golf, Jetta & GTI With Digifant II
1) Perform spark test. See SPARK TEST under IGNITION CHECKS.
If secondary spark is present, ignition control unit is okay. If
secondary spark is not present, turn ignition off. Disconnect ignition
control unit wire harness connector. Turn ignition on. Using a
voltmeter, measure voltage between terminal No. 2 (-) and terminal No.
4 (+) of connector. See Fig. 5.
2) Battery voltage should be present. If battery voltage is
not present, ensure continuity exists between terminal No. 2 and
ground. Continuity must also exist between terminal No. 4 and ignition
coil positive terminal. Repair wiring if necessary. If wiring is okay,
replace ignition control unit.Fig. 5: Checking Hall Control Unit Voltage (Typical)
Courtesy of Volkswagen United States, Inc.
IDLE SPEED, CO LEVEL & IGNITION TIMING
Ensure idle speed, CO level and base ignition timing are set

F - BASIC TESTING
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 09:10PM
to specification. If necessary, see the appropriate D - ADJUSTMENTS
article in this section. Refer to the following menu:
NOTE: For the appropriate D - ADJUSTMENTS article, go to:
* For Cabriolet, see: D - ADJUSTMENTS
* For Corrado SLC, see: D - ADJUSTMENTS
* For EuroVan, see: D - ADJUSTMENTS
* For Fox, see: D - ADJUSTMENTS
* For Golf, GTI, Jetta, see: D - ADJUSTMENTS
* For Passat GL 2.0L 4-Cylinder, see: D - ADJUSTMENTS - 4-CYL
* For Passat GLX 2.8L VR6, see: D - ADJUSTMENTS - VR6
IDLE SPEED & CO LEVELÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Idle RPM CO Level %
Cabriolet (1)
Digifant I ............. 750-850 ......... 0.3-1.2
Digifant II ............ 750-850 ......... 0.3-1.1
Corrado SLC (2) ......... 650-750 ......... 0.3-1.5
Fox ................... (3) 875-925 ....... 0.3-1.2
Golf, Jetta & GTI (2)
800-880
0.3-1.2
Passat GL ............ (4) 800-1000 ....... 0.2-1.2
Passat GLX (2) .......... 650-750 ......... 0.3-1.5
(1) - With engine running, after reconnecting Blue coolant
temperature sensor. See the D - ADJUSTMENTS article
in this section for more information. See menu above.
(2) - Idle speed and fuel mixture (CO level) are not
adjustable.
(3) - If A/C equipped, disconnect idle speed boost valve
harness connector when checking idle speed. Clamp
crankcase breather hose near emission control valve
when checking CO level.
(4) - Idle speed is not adjustable.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄIGNITION TIMING (Degrees BTDC @ RPM)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Checking Adjusting
Cabriolet (1) ....... 4-8 @ 2000-2500 .. 5-7 @ 2000-2500
Corrado SLC ............... (2) .................... (2)
Fox (1) ............. 4-8 @ 2000-2500 .. 5-7 @ 2000-2500
Golf, GTI & Jetta ... (3) 12 @ 800-880 ............ .....
Passat GL ........... 4-8 @ 800-1000 .... 5-7 @ 800-1000
Passat GLX ................ (2) .................... (2)
(1) - On Digifant I systems, ensure engine oil temperature

F - BASIC TESTING
Article Text (p. 11)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:10PM
is 176øF (80øC) and Blue engine coolant temperature
sensor is disconnected.
(2) - Ignition timing is computer controlled. Information
is not available from manufacturer.
(3) - Using Scan Tester (VAG 1551) in START BASIC SETTING
mode. Ignition timing is not adjustable.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄIGNITION TIMING ADVANCE (Degrees BTDC @ RPM)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Specification
Cabriolet
Digifant I (California) .......... (1) 27-33 @ 4500
Digifant II (Other 49 States) .... (1) 20-30 @ 2300
Fox
Digifant I (California) .......... (1) 27-33 @ 4500
Digifant II (Other 49 States) .... (1) 20-30 @ 2300
All Other Models ................................ (2)
(1) - With Blue engine coolant temperature sensor
connected. Specification is in addition to the
initial setting.
(2) - Ignition timing advance is computer controlled.
Information is not available from manufacturer.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ SUMMARY
If no faults were found while performing the tests in this
article, see H - TESTS W/O CODES article in this section for diagnosis
by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent
diagnostic procedures.
END OF ARTICLE