DPF regen with VAS 5054A guide and FAQ

Here is a quick guide on regenerate DPF for VAG vehicles with VAS 5054A scanner and some frequently asked questions about this regeneration:

Supported vehicle type: 1Zxx4x (Octavia II 2.0l/103 kW)

1Zxx5x (Octavia II 1.9l/77 kW)

1Zxx9x (Octavia II 2.0l/125 kW)

3Uxx5x (Superb 2.0l/103 kW)

Fault: Recommended procedure for the detection of saturation and recovery DPF.

Solution workshop: Detection of saturation: Vehicle self diagnostics.

01 – Engine electronics

 11 – Block of measured values

 Block 75, displayed field 3

The saturation value is given in percent.

Saturation limit values:  1) up to 75% - the recovery is carried out during driving by engine control unit itself; 2) over 75% - the recovery carried out using the VAS 5054A diagnostic devices.


- speed over 60 kmph;

 - engine speed 1800–2500 rpm;

 - enter 15 Access right, Coding 2 function number 21295;

 - watch the measured value block 75 field 3, the saturation value has to be dropped to 15%;

 - the whole procedure takes 10 to 15 min.

Some questions and answers that may help about DPF regen:

Question: The glow plug symbol is flashing. Why? What should be done?

Answer: The DPF regeneration has not been completed during normal driving and now DPF has reached its maximum saturation at which it can still be regenerated. The limit value depends on variant and Model Year, but is in the range of 105% - 125%.Possible causes for this are:
a.) Frequent short distance journeys, i.e. high soot loading while at the same time regeneration of the DPF does not take place because the conditions necessary were not fulfilled.

b.) Frequent
interrupted regenerations, i.e. the engine was switched off during regeneration. Applies to short journey drivers who have at least fulfilled the conditions for triggering regeneration. If the glow plug light flashes, the vehicle

a.) Engine running since start for longer than 2 minutes.
b.) Calculated saturation higher than 80%.

c.) Coolant temperature over 70°C for at least 2 minutes.
d.) No DPF-relevant faults stored in system.
e.) A defined vehicle speed
threshold must have been exceeded (e.g. for >80% loading, 100 km/h)

Question: Under what conditions is regeneration interrupted/ended once it has started?

Answer: Normally when regeneration has been successfully completed, or:

a.) After a maximum regeneration time (20 - 25 min.).
b.) If the engine is switched off or has stalled.
c.) If the engine is left idling for along time (5 - 10 min.).
d.) If 1000°C is detected by the exhaust temperature sensor.
e.) If during regeneration, a fault is detection the components relevant for combustion (injection/intake system).

If the regeneration is interrupted once started but before it has been 50% completed, the glow plug lamp flashes on the next engine start (cold or hot) and regeneration begins again once the operating conditions have been fulfilled.


How does regeneration affect the oil life?

Answer: On each regeneration or attempted regeneration, a certain diesel fuel amount is injected into the engine oil which reduces the oil life. If the "INSP" light in the instrument cluster comes on, the engine oil is exhausted and must be changed. Failure to do so could damage the engine.