Testing intake air temperature sender -G42 — AUDI

APZ ARJ ARN
Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1594 A
V.A.G 1598/31
VAS 5051 with VAS 5051/1

or

V.A.G 1551 with V.A.G 1551/3 A

Fitting location => Fitting locations overview, Page
24-5

Test sequence

Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( => Page
01-3
.)
When doing this the ignition must be switched on.

Rapid data transfer
HELP
Select function XX
Indicated on display:

Enter "08" to select the function "Read measured value block" and confirm entry with Q key.

Read measured value block
Q
Enter display group number XXX
Indicated on display:

Enter "004" to select Display Group 004 and confirm entry with Q key.

Read measured value block 4
⇒
1
2
3
4
Indicated on display:

Check display value for intake air temperature sender(display zone 4):

Display zones
1 · 2 · 3 · 4
Display Group 004: Intake air temperature with engine idling
Display · xxxx rpm · xx.x V · xxx.x °C · xxx.x °C
Indicates · Engine speed · Battery voltage · Coolant temperature · Intake air temperature
Range · 0 ... 6800 rpm · 10.0 ... 15.0 V · -48.0 ... 143.0 °C · -48.0 ... 143.0 °C
Specification · xxxx rpm · 12.0 ... 15.0 V · 80.0 ... 110.0 °C · Between ambient temperature and 120 °C 1)

1)
Possible readouts:

When the vehicle is being driven this figure may be up to 24 °C higher than ambient temperature.

When the vehicle is standing, temperatures up to 120 °C are possible due to heat radiated from the engine.

Checking wiring connections

Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
=> Page
24-20
.

Test for open circuit and short to positive or earth in the following wiring connections:

Connector / Contact · Test box V.A.G 1598/31 / Socket
1 · 85
2 · 108

Test for short circuits between the two wires.
Rectify any open/short circuit as necessary.

If no fault in wire is detected:

Testing sender

Unplug connector from intake air temperature sender.

Connect multimeter (resistance measurement range) to sender.

Specifications:

Temperature (°C) · Resistance (kω)
-20 · approx. 13.8
0 · approx. 5.5
20 · approx. 2.4
40 · approx. 1.1
60 · approx. 0.6

Example:

If the air temperature is between 0 °C and 20 °C, the resistance should be between 5.5 kωand 2.4 kω.

If the specification is not attained:

Fit a new intake air temperature sender.