Display Group 017

Notes on Display group 017:

Display group 017 is used to perform selective diagnosis if the value of the Exhaust Gas Recirculation (EGR) system flow diagnosis, display group 023, display field 1, is not set to "0" during resetting of the "Readiness Code" and/or a malfunction is stored in the Diagnostic Trouble Code memory that relates to the EGR system.

During a cold start of -10°C to 30°C (14°F to 8°F), EGR will not take place at idle and during "Basic Setting" function 04. Since the EGR is automatically switched off during "Basic Setting" function 04 the diagnosis of the EGR flow test can only be checked in "Read Measuring Value Block" function 08.

When the diagnostic conditions are fulfilled, the ECM checks the flow through the EGR system after each engine start. The diagnostic conditions are only met (diagnosis active) during a drive of approx.. 1 1/2 to 5 min. at 50-62 mph (80-100km/h) in 4th or 5th gear within the conditions listed below. EGR flow test (EGR quantity) is active as soon as the following conditions are met.
^ Vehicle speed: constant drive
^ Engine speed: 2000-3000 RPM (see display group 003)
^ Engine load: 32-58%

DISPLAY OVERVIEW

VAG 1551 Display Overview, Display Group 017:

Notes on display fields 1 and 2:
^ Time counters are displayed in display fields 1 and 2. The end value of counter 1 is "2" and the end value of counter 2 is "0".
^ If the diagnostic conditions are fulfilled, the counter is increased. If the diagnostic conditions are not fulfilled, the counter is decreased.
^ Counter 1 is increased by 1 as soon as counter 2 reaches the value "255". If value "255" is reached, counter 2 returns to "0" and starts to count to "255" again. When value "255" is reached a second time, counter 2 jumps to its end value "0" and counter 1 to its end value "2".
^ Diagnostic is ended as soon as both counters have reached their end values. However, diagnostic is only recognized OK if the EGR temperature in display field 4 is greater than 65°C (149°F) at the end of diagnostic.
^ If EGR temperature is greater than 65°C (149°F) at the end of the first diagnostic, diagnostic is ended. If the EGR temperature is less than 65°C (149°F) at the end of the first diagnostic, the EGR flow test continues.
^ If the EGR flow test is to be repeated immediately or once again after an OK diagnosis, stop engine, then restart.