With VAG 1551

REQUIREMENTS
- Fuses 18 and 21 OK.
- Ground connections OK (engine ground connection: at cylinder head cover on left and beneath lower section of the intake manifold).
- Engine coolant temperature 80°C (176°F) minimum.
- All electrical consumers switched OFF.
- A/C switched OFF.
- Exhaust system must be leak tight.
- Start engine and let idle.
- Activate Diagnostic Trouble Code (DTC) memory and then erase.
- Connect EPA 105 CO tester or equivalent to CO tap tube using VAG 1363 (High temperature adaptor hose).

PROCEDURE
- Connect Scan Tool (ST) VAG 1551 Refer to Connecting and Operating VAG 1551 Scan Tool. The following displays appear alternately:

VAG On Board Diagnostic HELP.
1-Rapid data transfer.

VAG On Board Diagnostic HELP.
2-Blink code output.

NOTE: If there is no display, check the voltage supply for scan tool. Refer to VAG 1551 /Voltage Supply Checking.

- Press 1 button to select operating mode "Rapid Data Transfer".

VAG 1551 Selectable Functions:

Selectable Function Table

- Select Start Basic Setting from function table and input, display will appear as shown:

Start basic setting HELP.
Input Display group number XX.

- Input Display group number 01, display will appear as shown:

System in Basic Adjustment 1.
1 2 3 4.

NOTE: When this mode is selected; the EVAP solenoid valve 1 (N 80) is closed.

- Engine coolant temperature is displayed in field 2 and must be 80°C (176°F) minimum before proceding to next step.
- Raise engine speed briefly then let engine idle for 2 minutes.
- Read display value for engine RPM and ignition timing point as follows:

^ Display field 1; engine RPM must be 650 to 750 RPM.
^ Display field 4; ignition timing point must be 6° BTDC and fluctuating.

- Observe CO content on tester; checking value must be 0.3 to 1.5 Vol.%.
- press 0 and 6 buttons to select function 06 "Ending output".
- If specified values are not obtained;

^ Check gas pedal for ease of movement. Correct as necessary.
^ Check Dashpot.
^ Check Throttle Position (TP) Sensor.
^ Check Idle Air Control (IAC).
^ Check EGR valve.
^ Check intake system for air and vacuum leaks.