Audi Workshop Service and Repair Manuals

Test requirements:

• ◆ No leaks in exhaust system
• ◆ Coolant temperature at least 80 oC.
• ◆ Throttle valve in idling position (adjust accelerator cable)

=> 4-cylinder Engine, Mechanics; Repair group 20; Removing and installing parts of fuel supply system; Servicing accelerator mechanism

• ◆ All electrical loads off.
• ◆ Air conditioning switched off.
• ◆ Pressure gauge not connected
• ◆ Vehicles with automatic gearbox: Selector lever in position P or N

Checking idling speed

Notes:

• ◆ The idling speed cannot be adjusted.
• ◆ The idling speed is checked in function 08 "Read measured value block".

• ‒ Interrogate fault memory =>Page 01-8. 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.
• ‒ Leave engine idling.
• ‒ Switch off air conditioner.
• ‒ Switch off rear window heating.
• ‒ Place selector lever in P or N position (automatic gearboxes).

• ‒ Read measured value block (function 08) and select Display group 05 =>Page 01-49.

• ‒ Read off idling speed from Display zone 1.

Specification: 820...900 rpm

• ‒ Press the ⇒key
• ‒ Enter 06 for `End output' and confirm entry with Q-key.
• ‒ If the specified result is not achieved, interrogate the fault memory again =>Page 01-8.

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 a dot:

• ● Test idling switch =>Page 24-62.
• ● Large quantity of unmetered air =>Basic setting of engine, Display group 01, 05 or 08.
• ● Check throttle valve control part =>Page 24-58.

Testing CO content:

It is not possible to adjust the CO content.

It is not possible to test the CO content upstream of the CAT.

To assess the exhaust upstream of the CAT, it is necessary to check the Lambda control values and the Lambda learned values in the self-diagnosis.

• ‒ Interrogate fault memory =>Page 01-8. 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.
• ‒ Leave engine idling.
• ‒ Read measured value block (function 08) and select Display group 03 =>Page 01-49.

Do not proceed with the test until the coolant temperature shown in Display zone 3 has reached at least 80 oC.

• ‒ Press the C key
• ‒ Press keys 0 and 9 (Display group 09 is selected with 09) and confirm the entry with the Q key.

• ‒ Compare the displayed values to the specified values=>Page 01-86.
• ‒ If the values are not as specified, rectify the fault and repeat the test.
• ‒ Press the C key
• ‒ Press keys 0 and 8 (Display group 8 is selected with 08) and confirm entry with the Q key.

• ‒ Compare the displayed values to the specified values =>Page 01-83.
• ‒ If the values are not as specified, rectify the fault and repeat the test.
• ‒ Press the ⇒key
• ‒ Press keys 0 and 6 for "End data transfer" and confirm entry with the key Q.