Volkswagen Golf / Golf GTI / Jetta. Manual — part 973

87-104

Test conditions

Making
connections

Notes:

Workshop

temperature: 20
30 C (68-86 F)

Engine at

Workshop
temperature.

The following test

procedure is only
possible on
vehicles where
the -G65- square
wave signal to the
coolant fan
control module -
J2293- is also
transmitted to the
Motronic Engine
Control Module
(ECM). Confirm
G65- circuit using
wiring diagram.

On vehicles

where -G65- is
NOT connected
to the ECM,
connect green
clip from VAG
1767 directly to
G65- pin 2 using
appropriate VAG
1594 adapter
cable -7-.
Proceed directly
to checking

Page 87-105

-

Disconnect
engine
harness
electrical
connector

A/C refrigerant system, servicing

13/2/2005

from
Engine
Control
Module
(ECM) -3

- Locate correct test

box VAG1598A
4- and adapter
according to pin
assignments of
ECM -3- and
connect test box
to engine wiring
connector/harness
-2-.

A/C refrigerant system, servicing

13/2/2005

87-105

Notes:

- Connect

black clip
from
VAG1767
to
Ground
(GND) -
5-.

- Determine

applicable -
G65- signal
input pin
assignment
to ECM
using
wiring
diagram.
Example:
T121/61

As -G65-

function
primarily
controls
coolant fan
and A/C
clutch
operation, the
engine wiring
diagrams
may indicate
the -G65-
signal
connection as
being"Coolant
fan control
module
connection".

ECM

terminal
number
assignments
correspond
with those
on test box
VAG1598A.

A/C refrigerant system, servicing

13/2/2005

Checking

- Connect

green clip
from
VAG1767 to
the
corresponding
numbered
position on
test box
VAG1598A
connected to -
G65- pin -2-
using
appropriate
VAG 1594
adapter cable
-7- .Example:
61

- Switch

ignition
on.

- Press button

(arrow) for
Duty Cycle
measurement
(modulation
ratio) on
ignition tester
VAG 1767.

A/C refrigerant system, servicing

13/2/2005