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Checking exhaust gas temperature senders > < Removing and installing exhaust manifold

A4 Mk1

6-Cylinder engine (5-valve turbo), Mechanics
Removing and installing parts of exhaust system
Testing function of exhaust gas temperature senders
 
W00-0706

Special tools and workshop equipment required

  • ◆ VAS 5051 with VAS 5051/1
  • or
  • ◆ V.A.G 1551 and V.A.G 1551/3 A

Test requirement:

  • ● Coolant temperature at least 80 °C
Warning
  • ◆ Test equipment must always be secured on the rear seat and operated from the rear seat by a second person.
  • ◆ If test equipment is operated from the front passenger seat, the occupant could be injured by the passenger's airbag in an accident.

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".
    When doing this the engine must be idling.

=> Motronic injection and ignition system; Repair group 01; Self-diagnosis of Motronic; Connecting vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 and selecting functions.
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Enter "08" to select the function "Read measured value block" and confirm entry with Q key.
 
→ Indicated on display:
Read measured value block    Q
Enter display group number XXX
  • ‒ Enter "112" to select Display Group 112 and confirm entry with Q key.
 
→ Indicated on display:
(1...4=Display zones)
Read measured value block 112    ⇒
    1    2    3    4
  • ‒ Check exhaust gas temperature.
  • ‒ Perform a road test during which
    • ‒ Full throttle at engine speeds between 5000...6500 rpm
  • is attained.

Note:

The exhaust gas temperature should increase to above 980°C to initiate the control process. Values below 945°C are indicated as 945°C.

Display zones

1

2

3

4

Display group 112: Exhaust gas temperature

Display

°C

%

°C

%

Indicates

Exhaust gas temperature Bank 1

Enrichment factor sensor Bank 1

Exhaust gas temperature Bank 2

Enrichment factor sensor Bank 2

Specification

980 1)

max. 40 2)

980

max. 40 2)

Note

Control process is only initiated at exhaust gas temperatures above 980 °C

A fault will be registered in the memory if the enrichment factor exceeds 30 %

Control process is only initiated at exhaust gas temperatures above 980 °C

A fault will be registered in the memory if the enrichment factor exceeds 30 %

1)    Values up to 1025°C can be indicated for a short period of time during the starting-up process.

2)    Values of 25% can be indicated for a short period of time during the starting-up process.

If values above 20% are indicated continuously, then possible causes could be:

  • ◆ Fuel pressure too low.
  • ◆ Air mass meter signal too low.
  • ‒ Proceed to measured value block 220.
 
→ Indicated on display:
(1...4=Display zones)
Read measured value block 220    ⇒
    1    2    3    4
  • ‒ Check exhaust gas temperature control.

Display zones

1

2

3

4

Display group 220: Exhaust gas temperature control

Display

xxxx rpm

%

%

Text

Indicates

Engine speed

Load

On-off ratio sensor Bank 1

Operating status Bank 1

Specification

> 5000

> 100

42 ± 10

Control ON

Note

Increase engine speed and load until control switches to "ON"

  • ‒ Repeat test procedure for Bank 2=>Measured value block 221

Display zones

1

2

3

4

Display group 221: Exhaust gas temperature control

Display

xxxx rpm

%

%

Text

Indicates

Engine speed

Load

On-off ratio sensor Bank 2

Operating status Bank 2

Specification

> 5000

> 100

42 ± 10

Control ON

Note

Increase engine speed and load until control switches to "ON"

If the specifications are not obtained and a fault is stored in the fault memory:

  • ‒ Check exhaust gas temperature sender.

Checking exhaust gas temperature senders > < Removing and installing exhaust manifold