Fig. 13
Reference Information – HV adapters and text descriptions

adapters before performing the
HV component measurements
(Fig. 14).
•

This procedure is essential to
ensure that the HV adapters
are in good condition prior to
using them.

•

Perform the VAS 6558A
resistance measurement
calibration routine whenever
prompted to do so during the
GFF test plan (Fig. 15).

•

The pointed tips from the VAS
6558A kit are not used with the
HV measurement adapters, but
are needed for performing the
calibration. Install the pointed
tips when prompted to “merge”
the red and black probes.

•

Take care to press the button
on the red probe only as
instructed.

•

For the first run-through, the
“overall system” check should
be performed (Fig. 16).

•

The “individual HV component”
check is used to repeat the
measurements for validation
purposes on a single
component that is suspicious or
questionable after running
through the complete
measurements of all
components.

•

At individual components on
the auxiliary circuit, the
measurements may be
repeated directly at the
component using the
appropriate HV measurement
adapter VAS 6558A/36A or

Fig. 14

Fig. 15

Fig. 16

VAS 6558A/37A as needed,
depending on the connector
type.
•

Take care to observe small
changes in the text.

•

In the example shown, the first
test will be a series of
measurements at the DC
charging connection of the HV
battery (e.g., with VAS 6558A
/35 adapter plugged into the
HV battery DC connection (Fig.
17).

•

Later the measurement is done
at the DC charging connection
to the HV battery (e.g., with
VAS 6558A/35 disconnected
from the HV battery and
connected only to the HV
connector leading up to the
charging socket (Fig. 18).

•

Designation of battery HV
connections used in the GFF
test plan (Fig. 19):

Fig. 17

Fig. 18

Fig. 19

a.

TNS connection of the
AX2 - High-Voltage
Battery 1

b.

AUX connection of the
AX2 - High-Voltage
Battery 1.

c.

DC charging socket of the
AX2 - High-Voltage
Battery 1.

Reference information – Connection of HV measurement adapters to vehicle
•

Example of HV adapter
connections at HV battery (Fig.
20):
a.

b.

VAS 6558A/35 connected
to TNS (traction
connector) of the HV
battery.

VAS 6558A/36A
connected to AUX
(auxiliary connector) of
the HV battery.
•

Example of black lead of VAS
6558A clipped to chassis
ground point at HV battery (Fig.
21).

•

Note that measurements of all
auxiliary components are
generally taken through the
auxiliary harness. After a
measurement is taken with all
of the components on the
auxiliary harness still
connected, all of the
components are disconnected,
and then reconnected one at a
time.

•

Example diagrams of HV
adapter connections and
designations of connectors at
HV battery as provided through
functional description
attachments within the GFF
test plan.

•

At auxiliary AUX and traction
network TNS connectors (Fig.
22)

•

At DC charging connector (Fig.
23)

Fig. 20

Fig. 21

Fig. 22

Fig. 23
•

Example of VAS 6558A/35
adapter connected with the DC
charging socket to the AX2 High-Voltage Battery 1 (Fig. 24)
and associated diagram (Fig.
25).

•

Note that the HV adapters are
never connected inline between
two components in this
measurement procedure!

•

Example of VAS 6558A/35
adapter connected with the JX1
- Electric Drive Power and
Control Electronics (Fig. 26).

•

Note that the measurements of
the rear electric drive JX1 are
taken through the HV harness,
because it is not possible to

Fig. 24

Fig. 25

disconnect the HV connector
from the JX1 – however, in
vehicles equipped with all
wheel drive, it is necessary to
then remove the HV connector
from the JX4 - Electric Drive
Power and Control Electronics
2 before taking measurements
of the JX1 (Fig. 27).
•

Under no circumstances should
the HV measurements be taken
with front (JX1) and rear (JX4)
connected to the HV harness at
the same time. Such
measurements would be
inconclusive and must be
repeated.

•

Measurements at the JX4 are
similar to the JX1, with the
exception that the VAS 6558A
/35 adapter is connected
directly into the HV connector
of the JX4 rather than through
the HV harness.

Fig. 26

Fig. 27

Fig. 28

Fig. 29
•

When taking the insulation
resistance measurements at
certain HV components with
250 Volts between HV+ and
HV- the normal value may be
low enough to cause what
appears to be an incorrect
result.

•

The insulation resistance test is
being used in this way to check
the HV component against a
good reference value and is not
being used to measure
insulation resistance against
the vehicle chassis.

•

In the example shown (Fig. 30)
the value 7818.01 Ohm is
within the normal range for the JX1- power electronics.

•

If the measurement is repeated
the value may increase, but
repeat measurements are not
necessary in this case (Fig. 31
and 32).

Fig. 30

Fig. 31

Fig. 32
•

Example showing connection of
the HV adapter VAS 6558A
/36A to the HV auxiliary
harness (Fig. 33 and 34).

•

The measurement of all
components on the HV
auxiliary harness is taken
through the harness first with
all components connected,
then with the harness only (all
components disconnected),
and lastly with each component
individually (reconnected one at
a time).

•

Example diagrams, showing
how single HV components are
normally measured one at a
time, through the auxiliary

Fig. 33

Fig. 34

harness. Diagrams are shown
for two components only, all
other components on the
auxiliary harness are checked
similarly (Fig. 35 and 36)

Fig. 35

Fig. 36
•

To remove the HV connector at
the -VX81- A/C Compressor,
first remove the harness
retainer clip (circled) from the
bracket (Fig. 37).

•

In vehicles equipped with fourwheel drive, a long right angle
pick tool with a solid handle is
useful for accessing the HV
connector (circled) of the -A19 Voltage Converter (Fig. 38).

Fig. 37

•

When removing the HV
connector, care must be taken
to avoid making contact
between the B+ post of the A19 - Voltage Converter and
chassis ground. The B+ post is
connected to the 12V battery
positive terminal through the
main fuse block SA.

•

After completing the entire set
of measurements for all
components in the HV system,
perform a repeat measurement
of any individual component
that was suspicious or
questionable.

•

For components on the HV
auxiliary harness, a direct
measurement at the
component is achieved using
the appropriate HV
measurement adapter VAS
6558A/36A or VAS 6558A/37A
as needed to match the
connector type on the
component being measured.

•

In the example shown (Fig. 39)
the VAS 6558A/37A is being
used to perform the
measurement directly at the Z132- Heating Element (PTC) 3
– Water Heater (Battery
Coolant Heating).

•

The VAS 6558A cannot
measure capacitance, therefore
a separate multimeter must be
used.

•

The VAG 1526B multimeter is
not distributed within North
America. Instead, the Fluke 83V or equivalent with a suitable

Fig. 38

Fig. 39

Reference information – Capacitance measurements

capacitance measurement
range and resolution may be
used (i.e., maximum
capacitance 9,999 µF,
accuracy ±(1% + 2), maximum
resolution 0.01 nF).

Fig. 40

•

Before taking a capacitance
measurement, it is necessary
to discharge any energy stored
in the capacitor being
measured (Fig. 40).

•

To discharge the capacitor,
perform a continuous voltage
measurement until 0.1V or less
is displayed.

•

Pay attention to whether the
capacitance measurement on
the multimeter display is given
as µF or nF, which will vary
according to auto-ranging
behavior (Fig. 41).

•

Select the units of capacitance
(either µF or nF) that matches
the value as it is displayed on
the multimeter

•

Then enter the value directly
from the multimeter according
to the units selected (Fig. 42).

•

Equivalent units:

Fig. 41

Fig. 42

‒

1,000 nF = 1 µF

‒

1 nF = 0.001 µF

Reference information – Diode test mode measurements
•

The diode test mode of the
VAS 6558A is used to test the
individual components (Fig. 43).

•

The response of the forward
voltage drop varies, according
to circuits contained in the
components.

•

Before doing the diode test, a
voltage measurement is taken
until any voltage present in the
capacitors of the component is
dissipated (Fig. 44).

•

The measurement using the
diode test mode will be
conducted when the button is
pressed, after the voltage
measurement is completed
(Fig. 45).

•

For the example given at -JX1power electronics in the
reverse direction, the voltage
4.43 V indicates the result is
OK and open circuit in the
blocking direction (Fig. 46).

Fig. 43

Fig. 44

Fig. 45

Fig. 46
•

For the example given at -JX1power electronics in the
forward direction, the voltage
drop 0.46V is acceptable for
the particular component under
test (Fig. 47).

•

The response of the forward
voltage drop varies, according
to circuits contained in the
components.