Volkswagen Golf / Golf GTI / Jetta. Manual — part 917

01-5

On Board Diagnostic (OBD)
from m.y. 2002

General information

OBD program text/data generated by control

modules installed on vehicles from m.y.
2002 may not be recognized by VAG
1551/1552 Scan Tools (ST) with the latest
program card. For example: scan tool
display shows "text 799",
"01529 /references" or similar.

Only the VAS 5051 Vehicle Diagnostic

Testing and Information System is capable
of processing all display text/data on these
vehicles.

All OBD program functions on vehicles

from m.y. 2002 should be performed
using the VAS 5051 Vehicle Diagnostic
Testing and Information System in
operating mode "Guided Fault Finding"
or "Vehicle Self-Diagonsis".

On Board Diagnostic (OBD) from m.y. 2002

13/2/2005

01-6

Climatronic On Board
Diagnostic (OBD) through
m.y. 2001

General information

The Climatronic control module receives

information from various electrical and
electronic sensors. This information is
processed by the control module according
to specified values and then provides
corresponding output signals that control
electrical components (actuators).

The Climatronic control module -J255- is

integrated into the A/C Control Head -E87-
and cannot be serviced separately. To
enable recognition of component
malfunctions or if there is an open circuit, the
control module is equipped with Diagnostic
Trouble Code (DTC) memory.

Should a malfunction be detected in a

monitored sensor or component, it is stored
in DTC memory.

When malfunctions which have a permanent

adverse effect on the operation of the
Climatronic are stored in DTC memory, the
A/C control head -E87- display flashes for
approx. 15 seconds when the ignition is
switched on. If there are DTCs that do not
cause the display to flash, the Climatronic
control module allows the Climatronic to
continue to operate in emergency mode at
the settings set on the display.

To determine malfunctions detected by

OBD, initiate the On Board Diagnostic
program and retrieve stored information
using the VAG 1551/1552 Scan Tool (ST) or
VAS 5051 Vehicle Diagnostic Testing and
Information System.

Malfunction information displayed by the

scan tool is listed on DTC tables that contain
notes on possible causes and repairs.

Climatronic On Board Diagnostic (OBD) through m.y. 2001

13/2/2005

01-7

Sporadic malfunctions (indicated in the readout

by "SP") are automatically cancelled if not
repeated in the next 50 engine starts.

Note:

Some components and functions of the

Climatronic are not monitored by OBD (e.g.
Interior Temperature Sensor Fan V42). If there is
a specific complaint and no malfunctions are
recognized after checking the Diagnostic Trouble
Code (DTC) memory, refer to the information
listed below.

Additional information:

Climatronic, servicing

Page 87-25

A/C refrigerant system, servicing

Page 87-

89

Wiring diagrams

"Electrical Wiring Diagrams,

Troubleshooting &Component Locations"

Information covering symptoms/causes and

corresponding "Service Fixes"

Technical

Bulletins.

Climatronic On Board Diagnostic (OBD) through m.y. 2001

13/2/2005

01-8

Climatronic - On Board Diagnostic
(OBD), initiating & checking control
module versions

Note:

The following applies to models through m.y.

2001 ONLY. OBD from m.y. 2002

Page 01-5

.

Test requirements:

All fuses OK according to wiring diagram

Voltage supply OK (at least 11.5 V).

Scan Tool VAG 1551 or VAG 1552

connected.

Notes:

Connecting Scan Tool

Page 01-2

.

The following description applies only to Scan

Tool VAG 1551.

- Switch on ignition.

- Switch on printer with the PRINT button

(indicator lamp in button lights up).

- Press button -1- to select operating mode 1,

"Rapid data transfer" .

Climatronic On Board Diagnostic (OBD) through m.y. 2001

13/2/2005