Checking air flow meter -G19 - engine codes AAT, AEL — AUDI

ABP AEL
Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1594 A
V.A.G 1598 with V.A.G 1598/5
VAS 5051 with VAS 5051/1 and
VAS 5051/2

Test sequence

Read measured value block, display group 000, ignition on
=> Page
01-60
.

Readout on VAS 5051:

Check display in zone -10-.
Specification: 41 ... 75

If reading does not match specification:

Check exhaust gas recirculation.

=> 5-cyl. Diesel Engine, Mechanics (2.5 l engine); Repair Group 26; EGR system
5-cyl. Diesel Engine, Mechanics (2.5 l engine)
EGR system

Attention:
To avoid risk of accident when performing measurement and test drives, pay attention to safety precautions => Page
23-1
.
Accelerate vehicle in 3rd gear from 1500 rpm at full throttle while a second mechanic observes the rev counter.
At 3000 rpm the second mechanic presses the Print button on the VAS 5051.

Readout on VAS 5051:

Check display in zone -3-.
Specification: 255 (accelerator pedal floored)

Note:

If the readout is less than 255, the accelerator pedal was not floored.

Repeat test and accelerate vehicle at full throttle.

Check display in zone -10-.
Specification: min. 190 (provided charge pressure OK)

If reading does not match specification:

Replace air flow meter -G19.

If reading matches specification:

Terminate function "08 - Read measured value block" by touching ◂ key.
Touch "06 - End output".
Switch off ignition.

If a constant 139 is displayed:

Use current flow diagram to check for open circuit/short circuit in wiring between air flow meter and engine control unit.
Use current flow diagram to eliminate open circuit in wiring/short circuit.

Checking power supply

Unplug connector of air flow meter -G19 => Exploded view of fitting locations -item
23-12
.
Connect up multimeter for voltage measurement between contacts 3 and 4 of connector.
Switch on ignition.
Specification: approx. 5 V

Switch off ignition.

If reading does not match specification:

Check wiring

With ignition switched off, use adapter V.A.G 1598/5 to connect test box V.A.G 1598A to engine control unit connector only (not to control unit) => Page
23-45
.
Check for open circuit and short to earth/positive in the following wiring.

Connector / Contact · Test box V.A.G 1598 A / Socket
1 · 52
2 · 38
3 · 34
4 · 13

Use current flow diagram to eliminate open circuit in wiring/short circuit.