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4-cylinder injection engine (1.4 l and 1.6 l engine) > < Engine codes AGP, AQM

Golf Mk4

Checking exhaust gas recirculation
   
Checking exhaust gas recirculation
Special tools and workshop equipment required
t  Hand multimeter -V.A.G 1526B-
t  Auxiliary measuring set -V.A.G 1594C-
t  Test box -1598/22-
t  Test box -1598/31-

Not illustrated
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with diagnosis lead -V.A.G 1551/3C-
t  Current flow diagram
Test procedure
The exhaust gas recirculation function is checked in function 04 (basic setting). Using this method the exhaust gas recirculation valve is pulsed every 10 seconds, so that the extreme values for exhaust gas recirculation (air mass meter) can be read in display zone 3 in measured value block 003.
–  Connect fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with diagnosis lead -V.A.G 1551/3C- and select engine control unit with “address word” 01. The engine must be at idle when doing this: → Rep. Gr.01
   
Indicated on display:
–  Press keys 0 and 4 for “Initiate basic setting” function and confirm with Q key.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Press keys 00 and 3 for “Display group number 3” and confirm with Q key.
Engine codes AGR, AHF, ALH, ASV
  
Basic setting                       HELP
Input display group number XXX
Indicated on display: (1…4 = display zones)
The display in display zone 2 must fluctuate every 10 secs. between EGR active and EGRn.active.
The displays in display zone 3 and 4 must fluctuate within the following control range:
  Note
If a constant 550 mg/H is displayed in display zone 3; check air mass meter: → Rep. Gr.23
EGRn. active
–  Specification display zone 3: 400…580 mg/H
–  Specification display zone 4 0…5 %
EGR active
–  Specification display zone 3150…340 mg/H
–  Specification display zone 4 95…100 %
  Note
Displays in display zone 3 depend on pressure and therefore altitude. The values displayed are in relation to 0 m (sea level). If the values displayed deviate greatly due to the altitude, check in display zone 3 if a specified difference of min. 100 mg/H is achieved between displays for EGR active and EGRn.active.
If the specifications are not obtained:
–  Check mechanical exhaust gas recirculation valve → Chapter.
–  Check vacuum hoses → Chapter.
Engine codes AGP (with 121-pin control unit), AQM
  
System in basic setting  3            ->
   900 rpm EGRn.active   500 mg/H   0%
Indicated on display: (1…4 = display zones)
The display in display zone 2 must fluctuate every 10 secs. between EGR active and EGRn. active.
The display in display zone 4 must fluctuate within the following control range:
EGRn. active
–  Specification display zone 4 0…5 %
EGR active
–  Specification display zone 4 95…100 %
If the specifications are not obtained:
–  Check mechanical exhaust gas recirculation valve → Chapter.
–  Check vacuum hoses → Chapter.
Continuation for all engine codes
–  Check exhaust gas recirculation valve -N18- as follows:
–  Press the → key.
–  Press keys 0 and 6 for “End data transfer” function and confirm with Q key.
–  Switch off ignition.
  
System in basic setting  3            ->
    900 rpm    EGRn.active         0%
–  Pull connector -1- off exhaust gas recirculation valve -N18--2-.
–  Measure resistance at valve. Specification: 14…20 Ω
If the specification is not attained:
–  Renew exhaust gas recirculation valve -N18-
  Note
At room temperature the resistance is in the lower tolerance range, and at operating temperature in the upper tolerance range.
If the specification is obtained:
–  Switch on ignition.
  N23-0150
–  Measure supply voltage between valve connector -contact 1- and engine earth. Specification: approx. battery voltage
If the specification is not attained:
–  Switch off ignition.
Vehicles with 80-pin control unit
  V96-0749
–  Connect test box -1598/22- to control unit wiring harness.
  N24-0709
–  Check wiring between test box and connector for open circuit using current flow diagram. -Contact 1+socket 2+28- and -contact 2+socket 29- wire resistance: max. 1.5 Ω
–  Also check wiring for short to one another, short to earth and short to battery positive. Specification: ∞ Ω
Vehicles with 121-pin control unit
  V96-0749
–  Connect test box -1598/31- to control unit wiring harness.
  N24-0943
–  Check wiring between text box and connector for open circuit using current flow diagram. Contact 1 +socket 1 and contact 2 +socket 61 wire resistance: max. 1.5 Ω
–  Also check wiring for short to one another, short to earth and short to battery positive. Specification: ∞ Ω.
If no fault in lines is detected:
–  Renew diesel direct injection system control unit -J248- → Rep. Gr.23
  N24-1026

4-cylinder injection engine (1.4 l and 1.6 l engine) > < Engine codes AGP, AQM