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Check for proper operation > < Checking lambda control

Octavia Mk1

Poor vehicle handling after cold start
Poor vehicle handling after cold start
Test condition
l  No fault related to the lambda control is stored. Eliminate possible faults and erase fault memory.
The time which passes until the control (necessary probe temperature approx. 300°C) is introduced, is influenced mainly by the following factors:
t  Ambient temperature (summer/winter)
t  Operating conditions after start
t  Function of the probe heater
If faults occur after cold start, it must be checked if the problem occurs before or after the control is introduced.
Test vehicle under cold start conditions:
–  Connect vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3- → Chapter.
–  Select function “Read measured value block” (function 08) and display group 007 → Chapter.
   
Readout on display:
The signal voltage of the lambda probe is displayed in the display field 2.
If vehicle is cold or when the lambda control does not function: 0.45...0.50 V.
  WARNING
Operate the -V.A.G 1552- with 2 mechanics.
–  Perform test drive and while doing so observe the display field 2.
  
Reading measured value block 7        ->
1          2             3             4
The voltage signal must fluctuate between the ranges 0.0...+0.3 und +0.7...+1.0 V when introducing the control.
Voltage values greater than +0.7 V mean a richer mixture composition (less oxygen in the exhaust)
Voltage values less than +0.3 V mean a leaner mixture composition (more oxygen in the exhaust)
–  If a poor vehicle handling occurs before inserting the lambda control, the lambda control cannot be the cause of the fault.
–  If a poor vehicle handling occurs only after inserting the lambda control, check operation → Chapter.
  Note
t  If the poor handling has improved after inserting the control, the cause of the fault (e.g. unmetered air, defective injection valve, etc..) is eliminated by engaging the control. This can be detected by reading out the lambda learned values.
t  Read measured value block (function 08) and select display group 008. If the specified values are not reached, eliminate fault.
t  In addition, read out the measured value blocks in the function 04 (basic setting). For this function, the activated charcoal filter system solenoid valve 1 -N80- is closed.
t  The lambda control can be switched off and on with the help of the display group 099. It can be switched back and forward between “Basic setting” (lambda control off) and “Read measured value block” (lambda control on) by pressing the buttons 4 or 8.
  
Reading measured value block 7        ->
1        0.780V          3             4

Check for proper operation > < Checking lambda control