Testing air mass meter (vehicles with intake manifold change-over function) — AUDI

ARM
Note:

In vehicles with intake manifold change-over function, the intake air temperature sender is integrated in the air mass meter, and is therefore not fitted as a separate component on the engine.

Testing operation

Test conditions

Coolant temperature at least 80 °C
Electrical consumers switched off (radiator fan must not run during test)
Air conditioner switched off
On vehicles with automatic gearbox, the selector lever must be in position "P" or "N".
Fuse for air mass meter OK

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

Test sequence

Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed.
(Connecting fault reader and selecting engine electronics control unit=>Page
01-4
.)

Rapid data transfer
HELP
Select function XX
Indicated on display:

Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

Read measured value block
HELP
Input display group number XXX
Indicated on display:

Press keys 0, 0 and 1 for "Display group number 1" and confirm entry with Q key.

Read measured value block
1
⇒
1
2
3
4
Indicated on display:
(1...4 = Display zones)

Check whether the coolant temperature is above 80 °C in display zone 2.
Change to display group 2 as follows:
V.A.G 1551: Press key 3
V.A.G 1552: Press key ↑

Read measured value block 2
⇒
1
2
3
4
Indicated on display:
(1...4 = Display zones)

Display zone 2 shows the intake air mass (milligrams per stroke).

Specification: 100...280 mg/stroke

Press the ⇒key.
Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
Switch off ignition.
If the values are not as specified or if the fault memory has recorded a fault relating to the air mass meter, test the power supply to the air mass meter=>Page
24-40
.

Testing power supply to air mass meter

Test fuse for air mass meter.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If fuse is OK, disconnect 4-pin connector -1- from air mass meter -2-.
Connect multimeter to measure voltage on connector contacts 3 and engine earth.
Start engine and run at idling speed.

Specification: 11...15V.

Switch off ignition.
If multimeter indicates zero voltage, test for open circuit and short to earth in wiring between fuse and contact 3 on connector. If necessary, repair wiring.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If the fuse and the wiring are OK but the meter still indicates zero voltage, test the fuel pump relay=>Page
24-33
.

If the power supply is OK, test the signal wire.

Testing signal wiring for air mass meter

Connect test box V.A.G 1598/22 to control unit wiring harness.

Test wiring from plug connector on air mass meter...

... to engine control unit for open circuit and short to positive or earth. Rectify if necessary.

Plug connector for air mass meter G70 · Test box V.A.G 1598/22 or control unit connector
1 · 13
2 · 12

If the wiring is OK, fit a new air mass meter -G70.