Checking electric radiator fan V7 and actuation: Audi 3.3 TDI (AKF)

Checking electric
radiator fan
V7
and actuation
Special tools and workshop equipment required
Portable multimeter
V.A.G 1526 B
or
V.A.G 1526 A
Voltage tester
V.A.G 1527 B
Adapter set
V.A.G 1594 C
or
V.A.G 1594 A
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnostic wire
VAS 5051/1
Test conditions
Electric fan fuses OK
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnostic wire
VAS 5051/1
connected, vehicle self-diagnosis and vehicle system
“01 - Engine electronics”
selected; when doing this, the ignition must be switched on
Test sequence
Display on
VAS 5051 A
In list
1
select function
“03 - Final control diagnosis”
.
Keep touching
→
key until the 3 relays of the electric radiator fan are consecutively actuated.
Depending on the relay energised, the electric radiator fan must run at low, medium or high speed.
Terminate function
“03 - Final control diagnosis”
by touching
←
key and switch off ignition.
A - If electric radiator fan does not run at all:
On vehicles with auxiliary heater, screw out bolts
arrows
for attaching exhaust pipe of auxiliary/supplementary heater to noise insulation.
Unfasten quick-release fasteners
1
and detach front noise insulation.
Unplug connector
2
to radiator fan in front of left wheel housing.
Connect up
voltage tester
V.A.G 1527 B
between contacts 1 and 2 to feed wire connector.
Repeat function
“03 - Final control diagnosis”
.
Keep touching
→
key until one of the electric radiator fan relays is actuated.
The LED must flash slowly.
Terminate function
“03 - Final control diagnosis”
by touching
←
key and switch off ignition.
If LED flashes:
Replace electric radiator fan.
If LED does not flash:
Check power supply and earth connection of electric radiator fan.
B - If electric radiator fan does not run in one or two speed settings:
Repeat function
“03 - Final control diagnosis”
.
Keep touching
→
key until the 3 relays of the electric radiator fan are consecutively actuated.
The 3 relays of the electric radiator fan must be consecutively energised (audible in driver's footwell).
Terminate function
“03 - Final control diagnosis”
by touching
←
key and switch off ignition.
If not all relays click:
Remove driver's storage compartment
General body repairs, interior
Rep. Gr.
68
.
Unscrew ABS control unit and lay it aside with wires connected
1
.
Unscrew holder
2
for ABS control unit and relays.
Start final control diagnosis again and consecutively actuate the 3 relays
Items 3 … 5
of the electric radiator fan.
Check power supply and actuation of the relay which does not click in final control diagnosis.
If all relays click:
On vehicles with auxiliary heater, screw out bolts
arrows
for attaching exhaust pipe of auxiliary/supplementary heater to noise insulation.
Unfasten quick-release fasteners
1
and detach front noise insulation.
Unscrew wires at connections
E1 … E3
at
radiator fan series resistor
N39
.
Connect up multimeter (resistance measuring range) between contacts
E1
and
E2
.
Specification: Approx. 0.45 ... 0.55 Ω
Connect up multimeter (resistance measuring range) between contacts
E2
and
E3
.
Specification: Approx. 0.45 ... 0.55 Ω
If readings do not match specifications:
Replace series resistor.
If readings match specifications:
Use current flow diagram to repair wiring.