1990 VOLKSWAGEN CORRADO Repair Manual

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 12)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PMFig. 8: Manual A/C-Heater System Wiring Diagram (Golf GL & GTI)

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 13)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PMFig. 9: Manual A/C-Heater System Wiring Diagram (Jetta)Fig. 10: Manual A/C-Heater System Wiring Diagram (Jetta GLi)

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 14)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PMFig. 11: Manual A/C-Heater System Wiring Diagram (Vanagon)
END OF ARTICLE

AA - USING THIS SECTION (GENERAL HELP INFORMATION)
Article Text
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
ARTICLE BEGINNING
ENGINE PERFORMANCE
How To Use This Section
INTRODUCTION
NOTE: Because there are so many possible combinations of
articles for the different manufacturers and models,
the new hyper-text capabilities built into this product
DO NOT apply to this article.
It is the purpose of this repair information system to help
professional automotive technicians maintain top vehicle performance
and correct driveability problems related to today's high tech
vehicles.
Because of the limited amount of space allowable for the this
product, our titles have been condensed to fit into the menus. An
alphabetical designation has been added to the front of each title to
allow the titles to be displayed in a way that reflects their
respective order of use. References to the titles in some of the
diagnostic flow charts sometimes will not correlate with the titles in
the this product menu. If not, refer to the MENU CROSS-REFERENCE table
below.
MENU CROSS-REFERENCE TABLEÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄTitle Associate Print (Book) Title:
A - ENGINE/VIN I D .................................... Introduction
B - EMISSION APPLICATION ..................... Emission Applications
C - TUNE-UP SPECS .............. Service & Adjustment Specifications
C - SPECIFICATIONS ............. Service & Adjustment Specifications
D - ADJUSTMENTS ............................. On-Vehicle Adjustments
E - THEORY/OPERATION ............................ Theory & Operation
F - BASIC TESTING ...................... Basic Diagnostic Procedures
G - TESTS W/ CODES ................................ Self-Diagnostics
H - TESTS W/O CODES .................... Trouble Shooting - No Codes
I - SYS/COMP TESTS ..................... Systems & Component Testing
J - PIN VOLTAGE CHARTS .......................... Pin Voltage Charts
K - SENSOR RANGE CHARTS .............. Sensor Operating Range Charts
L - WIRING DIAGRAMS ................................ Wiring Diagrams
M - VACUUM DIAGRAMS ................................ Vacuum Diagrams
N - REMOVE/INSTALL/OHAUL .......... Removal, Overhaul & Installation
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Because of this we recommend that you read the rest of these
INTRODUCTION paragraphs to better understand why the information is
presented in this new format.
The A - ENGINE/VIN I D article will help you identify the
vehicle and its systems. It will also explain the VIN code and in many
cases, show its location.

AA - USING THIS SECTION (GENERAL HELP INFORMATION)
Article Text (p. 2)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
If you want "TUNE-UP" type information, see D - ADJUSTMENTS
for the adjustment procedures. If you are familiar with the
procedures, but need a quick way to find the specification, go to C -
TUNE-UP SPECS or C - SPECIFICATIONS for the specifications pertaining
to the vehicle.
When diagnosing driveability problems, first go to F - BASIC
TESTING. This article is here to help eliminate wasted diagnostic
time. If the basic systems are working properly, go to G - TESTS W/
CODES.
If the vehicle still is having a driveability problem or if
the vehicle has no self-diagnostic system, go to H - TESTS W/O CODES.
This article will help you diagnose the problem by symptom, locate the
symptom exhibited by the vehicle, and inspect or test the items which
may be causing the problem.
After finding which specific system or component requires
testing, use the I - SYS/COMP TESTS article to tests the systems and
components. We have also included (when available) pin voltage charts
and sensor range charts. These can be found in J - PIN VOLTAGE CHARTS
and K - SENSOR RANGE CHARTS.
Also included in this section are wiring diagrams and vacuum
diagrams. These can be found in L - WIRING DIAGRAMS and M - VACUUM
DIAGRAMS.
When all diagnostic tests have been performed and the problem
has been discovered, it may be necessary to replace or overhaul the
defective part. This information can be found in
N - REMOVE/INSTALL/OHAUL.
The content of each of these articles is outlined below. As a
summary of the driveability diagnosis, see ROUTINE OUTLINE in this
article.
A - ENGINE/VIN ID
This article shows how to identify the model and engine by
its Vehicle Identification Number (VIN). A model coverage chart shows
each model and engine, the fuel system, ignition system and engine
code. The engine serial number locations are also included in this
article.
B - EMISSION APPLICATION
These charts identify the emission systems and sub-systems
applicable to each model and engine combination.
C - TUNE-UP SPECS
This is a collection of quick-reference type specifications.
This article is helpful when you are familiar with proper adjustment
procedures and only need specifications. Included in this section are:
* Battery specifications.
* Fluid capacities.

AA - USING THIS SECTION (GENERAL HELP INFORMATION)
Article Text (p. 3)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
* Replacement intervals.
* Belt adjustment.
* Engine Compression.
* Valve clearance.
* Valve Arrangement.
* Ignition coil specifications.
* High tension wire resistance.
* Spark plug type and gap.
* Firing order.
* Ignition timing.
* Fuel pump performance and injector resistance specifications
* Slow and fast idle speed and mixture specifications.
* Carbon monoxide (CO) level specifications.
* Throttle position sensor/switch specifications.
C - SPECIFICATIONS
This is a collection of quick-reference type specifications.
This article is helpful when you are familiar with proper adjustment
procedures and only need specifications. Included in this section are:
* Battery specifications.
* Fluid capacities.
* Replacement intervals.
* Belt adjustment.
* Engine Compression.
* Valve clearance.
* Valve Arrangement.
* Ignition coil specifications.
* High tension wire resistance.
* Spark plug type and gap.
* Firing order.
* Ignition timing.
* Fuel pump performance and injector resistance specifications
* Slow and fast idle speed and mixture specifications.
* Carbon monoxide (CO) level specifications.
* Throttle position sensor/switch specifications.
D - ADJUSTMENTS
This article contains the information that use to be included
in the TUNE-UP section. Checking and adjusting valves, spark plugs,
spark plug wires, base ignition timing and idle speed are found in
this section. Use this article for routine maintenance. Also, if you
have a driveability problem, ensure all on-vehicle adjustments are
correct before proceeding with any diagnosis.
E - THEORY/OPERATION

AA - USING THIS SECTION (GENERAL HELP INFORMATION)
Article Text (p. 4)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
This article covers basic theory and operation of engine
performance-related systems and components. Before diagnosing vehicles
or systems with which you are not completely familiar, read this
article.
F - BASIC TESTING
When diagnosing driveability problems, there are certain
"BASIC DIAGNOSTIC PROCEDURES" which must FIRST be performed. It is
necessary to perform a careful, complete check of basic engine
mechanical and electrical conditions, and verify spark availability
and adequate fuel supply.
The procedures apply to both computerized and non-
computerized systems. If all systems are okay, go to G - TESTS W/
CODES for vehicles with self-diagnostic systems or H - TESTS W/O CODES
for diagnosis by symptom.
G - TESTS W/ CODES
Use this article to retrieve and interpret trouble codes from
the engine computer self-diagnostic system. Once information is
retrieved, diagnostic procedures are given to help pinpoint and repair
computer system/component faults. Necessary steps for clearing trouble
codes are also given. If faults indicated by trouble codes are not
present at time of testing, proceed to TESTS W/O CODES for
intermittent testing procedures.
H - TESTS W/O CODES
This article helps trouble shoot driveability problems based
upon available "SYMPTOMS" and "INTERMITTENT TESTING" procedures.
Procedures in this section should lead you to specific component or
system tests which may or may not be computer monitored/controlled.
I - SYS/COMP TESTS
In this article, you will find tests for systems and
components related to air induction systems (turbochargers), fuel
control, ignition control, and emissions control systems.
J - PIN VOLTAGE CHARTS
PIN VOLTAGE CHARTS are supplied (where available) to speed up
the diagnostic process. By checking pin voltages at the electronic
control unit, it is possible to determine if the control unit is
receiving and transmitting proper voltage signals.
K - SENSOR RANGE CHARTS
Use the SENSOR OPERATING RANGE CHARTS to determine if a

AA - USING THIS SECTION (GENERAL HELP INFORMATION)
Article Text (p. 5)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
sensor is out of calibration. A sensor that is out of calibration may
not set a trouble code, but it will cause driveability problems.
L - WIRING DIAGRAMS
Use these WIRING DIAGRAMS to identify and trace component
circuits, locate shorts and opens in circuits, and understand how
individual circuits function as part of a system. The diagrams in this
article are only for fuel, ignition and emission systems
M - VACUUM DIAGRAMS
The VACUUM DIAGRAMS will assist you in finding incorrectly
routed vacuum hoses which may cause driveability problems or computer
indicated malfunctions.
N - REMOVE/INSTALL/OHAUL
N - REMOVE/INSTALL/OHAUL contains information found in the
sub-headings of REMOVAL, OVERHAUL & INSTALLATION. These are procedures
and specifications required to remove, overhaul (if possible) and
install components related to engine performance.
WHERE TO START
PERFORM BASIC INSPECTION
1) Verify customer complaint.
2) Perform visual inspection. See F - BASIC TESTING.
3) Test engine sub-system to determine that the following
systems are functioning properly. See F- BASIC TESTING.
* Mechanical conditions (compression)
* Ignition output
* Fuel Delivery
4) Check air induction system for leaks.
5) Check & adjust basic engine settings listed below to
ensure they are to specification. See D - ADJUSTMENTS.
* Ignition timing
* Idle speed
CHECK FOR TROUBLE CODES
1) If equipped with self-diagnostics, check for trouble
codes. Refer to G - TESTS W/ CODES.
2) Repair causes of trouble code(s).
3) Clear control unit memory.
SYMPTOM DIAGNOSIS