Checking fuel cooling pump V166 - vehicles with engine code letters AJM — AUDI

Checking
fuel cooling pump
V166
- vehicles with engine code letters AJM
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526 A
or
V.A.G 1526 B
Voltage tester
V.A.G 1527 B
Adapter set
V.A.G 1594 A
or
V.A.G 1594 C
Test box
V.A.G 1598/31
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnosis lead
VAS 5051/1
Test requirements
Fuse S 262 for
fuel cooling pump
V166
OK (located in relay carrier in electronics box in plenum chamber, position
10
)
Fault memory interrogated
Test sequence
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnosis lead
VAS 5051/1
is connected; vehicle self-diagnosis and vehicle system
“01 - Engine electronics”
is selected. When doing this the ignition must be switched on.
From the selection menu
1
select the diagnostic function
“03 - Final control diagnosis”
.
Press the button
→
until the
fuel cooling pump relay
J445
is activated.
The
fuel cooling pump relay
J445
(in the electronics box in the plenum chamber, position 2b) switches the
fuel cooling pump
V166
on and off at intervals over a period of about 30 seconds (audible at right in engine compartment).
Press the
←
button to exit from function
“03 - Final control diagnosis”
.
Press
“06 - End output”
.
Switch off ignition.
A - If the relay does not pick up:
Check power supply to
fuel cooling pump relay
J445
Anchor
.
Check activation of
fuel cooling pump relay
J445
Anchor
.
B - If the relay picks up but the fuel cooling pump does not run:
Check power supply to
fuel cooling pump
V166
Anchor
.
Checking power supply to
fuel cooling pump relay
J445
Detach rubber seal from plenum chamber cover in direction of
arrow
.
Detach plenum chamber cover
1
to front.
Unscrew bolts
arrows
and take off cover for electronics box in plenum chamber.
Detach
fuel cooling pump relay
J445
from position
2b
.
Connect up multimeter as follows to measure voltage.
Relay socket
contact
Specification
1 + earth
approx. battery voltage
3 + earth
approx. battery voltage
If specification is not reached:
Repair wiring connection if necessary.
Checking activation of
fuel cooling pump relay
J445
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnosis lead
VAS 5051/1
is connected; vehicle self-diagnosis and vehicle system
“01 - Engine electronics”
is selected. When doing this the ignition must be switched on.
Connect
voltage tester
V.A.G 1527 B
as follows:
Relay socket
contact
Measure to
5
Battery positive
From the selection menu
1
select the diagnostic function
“03 - Final control diagnosis”
.
Press the button
→
until the
fuel cooling pump relay
J445
is activated.
The LED should flash (does not go out entirely)
If LED flashes but relay does not operate:
Renew
fuel cooling pump relay
J445
.
If the LED does not flash:
Press the
←
button to exit from function
“03 - Final control diagnosis”
.
Press
“06 - End output”
.
Switch off ignition.
Pry off retainer bar with a screwdriver
arrow
.
Release retainer catches
arrows
and unplug connectors
1
and
2
from engine control unit.
Connect
test box
V.A.G 1598/31
to connectors of wiring harness; do not connect engine control unit. Connect earth clamp of test box to earth (not shown in illustration)
TDI injection and glow plug system (4-cyl.)
Rep. Gr.
23
.
Caution
To prevent damage to electronic components, select appropriate measuring range before connecting measuring leads and observe test requirements.
Check for open circuit and short to positive or earth in the following wiring:
Connector
Contact
Test box
V.A.G 1598/31
Socket
5
43
Repair wiring connection if necessary.
If no fault in wire is detected:
Renew engine control unit.
Checking power supply to
fuel cooling pump
V166
Vehicles with auxiliary heater: remove bolts
arrows
securing exhaust pipe for auxiliary/additional heater to noise insulation.
Release quick-fasteners
1
and
2
and take off front noise insulation. Leave rear noise insulation in position.
Unplug electrical connector
arrow
at
fuel cooling pump
V166
.
Connect
voltage tester
V.A.G 1527 B
between contacts
1
and
2
.
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnosis lead
VAS 5051/1
is connected; vehicle self-diagnosis and vehicle system
“01 - Engine electronics”
is selected. When doing this the ignition must be switched on.
From the selection menu
1
select the diagnostic function
“03 - Final control diagnosis”
.
Press the button
→
until the
fuel cooling pump relay
J445
is activated.
The LED should flash.
Press the
←
button to exit from function
“03 - Final control diagnosis”
.
Press
“06 - End output”
.
If the LED does not flash:
Perform the following checks marked with a dot.
Check wiring connection from connector at
fuel cooling pump
V166
to
fuel cooling pump relay
J445
(in electronics box in plenum chamber) for open circuit or short circuit according to current flow diagram.
Check wiring connection from connector at
fuel cooling pump
V166
to earth point for open circuit or short circuit according to current flow diagram.
If no fault is found:
Renew
fuel cooling pump
V166
.