K. Adjust CO Fuel Trim (FT) As Follows

K. Adjust CO Fuel Trim (FT) as follows





- With ignition OFF, disconnect hoses 1 and 2 from breather housing 3.
- Place hoses in such a way that only fresh air can be drawn in.

- Ensure that connector piece 4 (with opening) remains in hose 2.
- Disconnect differential pressure regulator harness connector -1-.





- Connect test adaptor VAG 1315A/1 between differential pressure regulator and harness connector (arrows).
- Switch Fluke 83 (US 1119) multimeter to 200mA range
- Connect multimeter to test adaptor VAG 1315A/1, using jumper leads from adaptor kit VW1594.
- Switch ignition ON. control current polarity (90 to 110 mA) must be positive If NOT, interchange test connections

- Continue on next page

- Start engine and let idle.
- Go to Engine Scan Tool and press 1 button to select "Rapid Data Transfer" mode.
- Press 0 and 1 buttons to select "Engine Electronics"
- Press 0 button to enter input.
- Press (arrow) button.
- Press 0 and 4 buttons to select "Basic Engine Adjustment".
- Press 0 button twice and press Q button.
^ idle must be 800-1000 RPM
- Observe CO content
^ must be 0.2 to 1.2 % Volume
^ adjusting value: 2.5+/- 2.5 mA (must fluctuate)
^ If NO
- Adjust control current, using CO Fuel Trim (FT) adjusting screw.
^ If NO
- Check oxygen sensor (G39) and oxygen sensor control, see Repair Manual, page 25-100.

Caution!
When adjusting CO Fuel Trim (F7):
^ DO NOT push down on wrench while adjusting.
^ Do NOT accelerate engine while wrench is inserted in adjusting screw.
^ Remove adjusting wrench after each adjustment and briefly raise engine spied before reading multimeter.

- Turn to Engine Scan Tool VAG 1551 and read Diagnostic Trouble Code (DTC).
^ if a malfunction (DTC) is indicated, make appropriate corrections and then erase DTC memory.
- Install new CO tamper-proof plug, Part No. 049 133 777B,
- Disconnect all test equipment.
- Reconnect all hoses and wire harness connectors.