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Encoding the control unit > < Final control diagnosis

A3 Mk1

Motronic fuel injection and ignitionsystem (4-cyl. turbo)
Self-diagnosis for the Motronic system
Basic setting

With the engine stopped, the following operation can be performed with the basic setting:

  • ◆ Adaptation of the throttle valve control unit to the engine control unit => Display Group 98

With the engine running, the following operations can be performed with the basic setting:

  • ◆ Learning process for lambda control
    => all display groups
  • ◆ Fault finding by selective actuation and deactuation of the lambda control => Display Group 99
  • ◆ Check the ignition timing
    => Display Group 95

Test conditions for operations with engine running

  • ● Coolant temperature at least 80 °C
  • ● Electrical consumers switched off (radiator fan must not run during the test)
  • ● Air conditioner switched off
  • ● Gear selector lever in P or N position
  • ● No fault stored in fault memory
  • ‒ Connect the V.A.G. 1551 fault reader and select the engine electronics control unit.
    .
  • ‒ Interrogating and erasing fault memory.
    => Page 01-7 No faults must be stored (if necessary, rectify fault, erase fault memory, switch off and re-start engine, perform test drive and interrogate the fault memory again as a check.
  • ‒ Leave engine idling.
 
→ Display readout:
Rapid data transfer      HELP
Select function XX
  • ‒ Press keys 0 and 4.

(04 is used to select the function "Basic Setting")
 
→ Display readout:
Rapid data transfer     Q
04-Basic setting
  • ‒ Confirm entry by pressing the Q key.
 
→ Display readout:
Basic setting      Q
Enter display group number     XXX
  • ‒ Enter the required display group number according to the list of display groups in "Reading measured value block" => Page 01-61.

Note:

Display Group number 00 is used here as an example to demonstrate the procedure.

  • ‒ Press key 0 three times.

(000 is used to select the function "Display Group 00").
 
→ Display readout:
Basic setting      Q
Enter display group number     00
  • ‒ Confirm entry by pressing the Q key.
 
→ Display readout:
Basic setting 0     Q
1    2    3    4    5    6    7    8    9    10

Display group 00 (decimal value)

▪ Engine running at idling speed

Display zones

Specified value

Corresponds to

1

2

3

4

5

6

7

8

9

10

Learned value for mixture formation
(if outside tolerance, perform test drive)

118...138

-8...+8 %

Learned value for mixture formation
(if outside tolerance, perform test drive)

115...141

-0.64...+0.64 ms

Control value for mixture formation
(if outside tolerance, perform test drive)

78...178

-10...+10 %

Learned value for idle stabilisation

120...136

-4.0...+4.0 kg/h

Control value for idle stabilisation

122...134

-3.0...+3.0 kg/h

Throttle angle

0...12

0...5 °

Battery voltage

142...206

10...14.5 V

Engine speed (idling speed)

80...92

800...920 rpm1)

Engine load (no consumers)

10...30

0.5...1.5 ms

Coolant temperature (pre-condition for basic setting)

170...204

80...105 °C

    1)    Current values:

=> Exhaust Emissions Check binder

  • ‒ Run engine at idling speed for a few minutes, coolant temperature at least 80 °C.
  • Display zone 1: specified value at least 170)

Notes:

  • ◆ Each time the PRINT key is pressed, the current display is printed out.
  • ◆ Press the C key before selecting further display groups.
  • ‒ If the specified values are achieved in all display zones, press the ⇒ key.
 
→ Display readout:
Rapid data transfer      HELP
Select function XX
  • ‒ Press keys 0 and 6.

(06 is used to select the function "End of output".)
 
→ Display readout:
Rapid data transfer     Q
06 - End of     output
  • ‒ Confirm entry by pressing the Q key.
 
→ Display readout:
Rapid data transfer      HELP
Select function XX

Encoding the control unit > < Final control diagnosis