1993 VOLKSWAGEN CORRADO sensor

VR65 ENGINE: AFFIX NEW VACUUM HOSE ROUTING LABEL
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 09:26PM
Fig. 4, marked "4") and secure with two (2) tie wraps,
part number N 020 902.2.
- Secure harness for temperature sensor (see Fig. 3, marked "A")
to battery ground cable (as shown in Fig. 4, marked "6") with
tie wrap, part number N 020 902.2.
- Push excess length harness downward.
- Carefully open re-usable tie wrap (see Fig. 4, marked "8")
- Route harness with protective sleeve (see Fig. 3, marked "7")
towards front above temperature sensor and re-secure with
re-usable tie wrap (see Fig. 4, marked "4").Fig. 4: Securing and Routing Harness
B. Modify Shaft Linkage Balance Weight Mounting
(Standard Transmission Vehicles Only)
- Remove air cooling hose for the front exhaust pipe (see
Fig. 5, marked "1") by loosening bolt (arrow), Pull hose
from air duct (see Fig. 5, marked "2")

TROUBLE SHOOTING - BASIC PROCEDURES
Article Text (p. 25)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:26PM
ator and fuel pump,
check for restricted
lines and filters
No distributor reference Repair ignition
pulses system as necessary
Open coolant temperature Test sensor and
sensor circuit wiring
Shorted W.O.T. switch in Disconnect W.O.T.
T.P.S. switch, engine
should start
Defective ECM Replace ECM
Fuel tank residual pressure Test for fuel
valve leaks pressure drop after
shut downÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄHard Starting Disconnected hot air tube Reconnect tube and
to air cleaner test control valve
Defective Idle Air Control Test valve operation
(IAC) valve and circuit
Shorted, open or misadjusted Test and adjust or
T.P.S. replace T.P.S.
EGR valve open Test EGR valve and
control circuit
Poor Oxygen sensor signal Test for shorted or
circuit
Incorrect mixture from PCV Test PCV for flow,
system check sealing of oil
filter cap
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄPoor High Speed Low fuel pump volume Faulty pump or
Operation restricted fuel
lines or filters
Poor MAP sensor signal Test MAP sensor,
vacuum hose and
wiring
Poor Oxygen sensor signal Test for shorted or
open sensor or
circuit
Open coolant temperature Test sensor and

TROUBLE SHOOTING - BASIC PROCEDURES
Article Text (p. 26)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:26PM
sensor circuit wiring
Faulty ignition operation Check wires for
cracks or poor con-
nections, test
secondary voltage
with oscilloscope
Contaminated fuel Test fuel for water
or alcohol
Intermittent ECM ground Test ECM ground
connection for
resistance
Restricted air cleaner Replace air cleaner
Restricted exhaust system Test for exhaust
manifold back
pressure
Poor MAF sensor signal Check leakage
between sensor and
manifold
Poor VSS signal If tester for ALCL
hook-up is available
check that VSS
reading matches
speedometerÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄPing or Knock on Poor Knock sensor signal Test for shorted or
Acceleration open sensor or
circuit
Poor Baro sensor signal Test for shorted or
open sensor or
circuit
Improper ignition timing See VEHICLE EMISSION
CONTROL LABEL (where
applicable)
Check for engine Low coolant, loose
overheating problems belts or electric
cooling fan
inoperative
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄNOTE: For additional electronic fuel injection trouble shooting
information, see the appropriate article in the ENGINE
PERFORMANCE section (not all vehicles have Computer Engine

WAVEFORMS - INJECTOR PATTERN TUTORIAL
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 09:26PM
Here is one example. Imagine a vehicle that has a faulty
injector driver that occasionally skips an injector pulse. Every
skipped pulse means that that cylinder does not fire, thus unburned O2
gets pushed into the exhaust and passes the O2 sensor. The O2 sensor
indicates lean, so the computer fattens up the mixture to compensate
for the supposed "lean" condition.
A connected dwell/duty meter would see the fattened pulse
width but would also see the skipped pulses. It would tally both and
likely come back with a reading that indicated the "pulse width" was
within specification because the rich mixture and missing pulses
offset each other.
This situation is not a far-fetched scenario. Some early GM
3800 engines were suffering from exactly this. The point is that a
lack of detail could cause misdiagnosis.
As you might have guessed, a lab scope would not miss this.
RELATIONSHIP BETWEEN DWELL & DUTY CYCLE READINGS TABLE (1)ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄDwell Meter (2) Duty Cycle Meter
1
ø .................................................... 1%
15
ø .................................................. 25%
30
ø .................................................. 50%
45
ø .................................................. 75%
60
ø ................................................. 100%
(1) - These are just some examples for your understanding.
It is okay to fill in the gaps.
(2) - Dwell meter on the six-cylinder scale.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ THE TWO TYPES OF INJECTOR DRIVERS
OVERVIEW
There are two types of transistor driver circuits used to
operate electric fuel injectors: voltage controlled and current
controlled. The voltage controlled type is sometimes called a
"saturated switch" driver, while the current controlled type is
sometimes known as a "peak and hold" driver.
The basic difference between the two is the total resistance
of the injector circuit. Roughly speaking, if a particular leg in an
injector circuit has total resistance of 12 or more ohms, a voltage
control driver is used. If less than 12 ohms, a current control driver
is used.
It is a question of what is going to do the job of limiting
the current flow in the injector circuit; the inherent "high"
resistance in the injector circuit, or the transistor driver. Without
some form of control, the current flow through the injector would
cause the solenoid coil to overheat and result in a damaged injector.
VOLTAGE CONTROLLED CIRCUIT ("SATURATED SWITCH")

WIRING DIAGRAM SYMBOLS
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 09:27PM
been created to make locating components easier. For these
articles, there will be a COMPONENT LOCATION MENU title in
the article main menu. These articles will also have the
original legend available on the first graphic.Fig. 1: Identifying Tie-Off Symbols
4) If the wires are not drawn all the way to another
component (across several pages), a reference will tell you their
final destination.
5) Again, use the legend on the first page of the wiring
diagram to determine the grid number and letter of the referenced
component. You can then turn directly to it without tracing wires
across several pages.
6) The symbols shown in Fig. 1 are called tie-offs. The first
tie-off shown indicates that the circuit goes to the temperature
sensor, and is also a ground circuit.
7) The second symbol indicates that the circuit goes to a
battery positive parallel circuit. The third symbol leads to a
particular component and the location is also given.
8) The lines shown in Fig. 2 are called options. Which path
or option to take depends on what engine or systems the vehicle has.Fig. 2: Identifying Option Symbols
COLOR ABBREVIATIONS IDENTIFICATION
COLOR ABBREVIATIONSÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄColor Normal Optional
Black .................. BLK ................... BK

WIRING DIAGRAM SYMBOLS
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 09:27PMFig. 9: Defogger GridFig. 10: FuseFig. 11: Fusible LinkFig. 12: GroundFig. 13: Glow Plug Resistor (In-Line) or Mirror HeaterFig. 14: Injector (Diesel) or Photocell (Gasoline)Fig. 15: Internal Fuse, Thermal LimiterFig. 16: Lamp (Dual Element)Fig. 17: Lamp (Single Element)Fig. 18: MotorFig. 19: Resistor (Internal)Fig. 20: Sensor, ThermistorFig. 21: SolenoidFig. 22: Solid State Device, TransistorFig. 23: Switch (Internal)

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 09:28PM
LEFT REAR MICRO SWITCH ............................... 9 (D 33)
LEFT SEAT BELT CONTROL UNIT .......................... 9 (D 35)
LIGHT SWITCH ...................................... 5 (A 18Ä19)
LUGGAGE COMPARTMENT LIGHT SWITCH ..................... 7 (A 26)
MAKE UP MIRROR ...................................... 11 (E 42)
O2 SENSOR .................................... 1,2 (A 3, A 5
Ä6)
OIL PRESSER GAUGE ................................... 9 (A 35)
OIL PRESSER SWITCHES ................................. 7 (A 25)
PARK BRAKE SWITCH .................................... 8 (A 31)
POWER MIRRORS ..................................... 11 (B
ÄD 42)
POWER WINDOW CIRCUIT BREAKER ........................ 10 (A 38)
POWER WINDOWS .................................. 11 (B
ÄD 36Ä39)
PROGRAM SWITCH ........................................ 3 (B 8)
RADIATOR COOLING FAN .................................. 1 (D 3)
RADIATOR COOLING FAN CONTROL UNIT ................... 1 (C-D 3)
RADIATOR COOLING FAN THERMO SW (SLC) .................. 1 (C 1)
REAR SPOILER SYSTEM ............................ 12 (A
ÄB 40Ä42)
REAR WIPER SYSTEM ................................. 7 (E 26
Ä27)
RIGHT SEAT BELT CONTROL UNIT ....................... 9 (B
ÄC 35)
SEAT BELT SWITCH ..................................... 8 (E 35)
SEAT HEATER SYSTEM ............................. 11 (C
ÄE 40Ä41)
SPEED SENSOR ......................................... 7 (B 26)
STARTER ............................................... 1 (A 3)
STARTER INTERLOCK/BACK-UP LIGHT RELAY (A/T) ........... 3 (A 8)
STOP LIGHT SWITCH .................................... 8 (B 29)
SUNROOF .......................................... 10 (E 36
Ä37)
THROTTLE POSITION SENSOR .............................. 2 (E 4)
VACUUM VENT VALVE ................................. 4 (B 13
Ä14)
VOLTMETER ............................................ 9 (B 35)
WINDSHIELD WIPER SYSTEM ......................... 7 (D
ÄE 24Ä27)
WARNING MODULE ................................ 4,8 (C
ÄD 12Ä28)
WASHER NOZZLE HEATERS ................................ 7 (E 27)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ WIRING DIAGRAMS