Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required

• ◆ VAS 5051 and VAS 5051/1

or

• ◆ Fault reader V.A.G 1551 with V.A.G 1551/3 A

Requirements for test:

• ● Exhaust system free of leaks
• ● Coolant temperature at least 80 °C
• ● Electrical consumers switched off (radiator fan must not run during the test)
• ● Air conditioner switched off
• ● No pressure gauge connected
• ● Vehicles with automatic gearbox: selector lever in position P or N

Notes:

• ◆ The idling speed cannot be adjusted.
• ◆ The idling speed is tested during the basic setting of the engine.
• ◆ During the basic setting of the engine, the solenoid valve for the activated charcoal filter (ACF valve -N80) is closed and the air conditioner compressor is automatically switched off.

Test sequence

• ‒ Interrogate fault memory . The fault memory must be clear. If necessary, rectify any faults and erase the fault memory. Switch off the engine, then start up again. Take vehicle for a test drive and interrogate the fault memory again to make sure it is clear.
• ‒ Run the engine at idling speed.

• ‒ Enter "04" to select "Basic setting" and confirm with Q key.

• ‒ Enter "056" for Display Group 056 and confirm entry with Q key.

• ‒ Check whether the engine speed shown in display zone 1 (actual engine speed) is within the specified tolerance range.

Notes:

• ◆ The value shown in display zone 1 is the actual engine speed.
• ◆ The value shown in display zone 2 (specified engine speed) is a theoretical value calculated by the engine control unit.
• ◆ When the engine is idling the engine control unit tries constantly to adjust the actual engine speed so that it matches the specified value.
• ◆ This means that the actual engine speed when idling should always be approximately the same as the specified engine speed.
• ◆ Display zones 3 and 4 provide additional information which is not relevant when checking the idling speed.

If the specification is obtained:

• ‒ Press ⇒key.

If the specification is not attained:

• ‒ Interrogate fault memory again .

Models with engine code letters ANB:

• ‒ If the fault memory was erased the readiness code must be generated again => Page 01-58.

If the idling speed is too high or too low and there are no faults recorded in the fault memory, carry out the following tests (marked with dots):

• ● Test for unmetered air in the intake system .
• ● Test throttle valve control part .
• ● Solenoid valve for activated charcoal filter constantly open
  Test .
• ● Perform adaption of throttle valve control part .

Relevance of figures in 5-digit readout for Display Group 056