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Engine control unit > < Testing exhaust gas recirculation

Octavia Mk1

Test sequence
Test sequence
The exhaust gas recirculation function is checked in function 04 (basic setting). As a result of this procedure the exhaust gas recirculation valve is pulsed every 10 seconds, so that the extreme values for the exhaust gas recirculation (air mass meter) can be read off in measured value block 003 in display field 3.
–  Connect vehicle system tester - V.A.G 1552-. Start engine and select the address word 01 “Engine electronics” → Chapter 01-1.
–  Enter function 04 “basic setting” and select display group number 003.
  Note
After selecting display group 003 and confirming with Q, the idling speed is increased by the engine control unit in display field 1 to 1380...1420 rpm.
   
Readout on display:
The display in display field 2 must switch between EGR not active and EGR active every 10 seconds.
The following readouts must fluctuate in display fields 3 and 4:
  Note
If a constant value of 539 mg/H and higher is shown in display field 3, test the air mass meter.
  
System in basic setting 3            ->
1400 rpm  EGR not active    500 mg/s     20 %
EGR not active:
 Specification in display field 3: 440…600 mg/s
Specification in display field 4: 18…22 %
EGR active:
 Specification in display field 3: 160…340 mg/s
Specification in display field 4: 63…67 %

If the specified values are not reached:
–  Test mechanical exhaust gas recirculation valve → 1.9 l/74 kW (TDI) Engine, Mechanical Components; Rep. Gr.26.
–  Inspect the connection diagram for the vacuum hoses → Chapter.
–  Test exhaust gas recirculation valve -N18 - → Chap. 01-1.
   

Engine control unit > < Testing exhaust gas recirculation