Forced DPF regeneration is a process that is used to clean and empty the diesel particulate filter of soot that is created by the process of combustion . When a DPF reaches a pre-determined particulate matter (PM) fill level (around 40%), the ECU will activate the regeneration process, which can inject up to eight times more fuel per stroke – a rate which is needed to produce temperatures in excess of 550°C , so that it can incinerate the soot that has been captured within the DPF 1. The regeneration process can't be done if:
- There is less than 15 L of fuel in the fuel tank or if the fuel light is on
- The pressure sensors are not working correctly
- The pressure sensor pipes are damaged – check for degradation under heat shield
- The EGR system is not working correctly
- Glow plugs module/glow plugs fault
- Throttle body fault
- The engine oil is the incorrect specification for the vehicle – must be Low Ash grade. Check the engine oil for diesel contamination (could be the result of regeneration)
In order to carry out a forced DPF regeneration, we use Autel diagnostics , up to date with 2024 Software. This operation could take up to 45 minutes. The regenaration process is conducted outside as high exhaust temperatures are very high , over 600 degrees .DPF Filters require more maintenance than catalytic converters. Engine oil ash builds up on the surface of the inlet face of the filter, and will eventually clog the pores. This increases the pressure drop over the filter, which, when it reaches a totally clogged state, is capable of causing turbo and engine damage. Regular filter maintenance is therefore a necessity. If the DPF is not regenerated and the Soot level fills to over 90% or 45g, the DPF will need replacing. This is not covered under any warranty. When fitting a new DPF, the ECU must be reset before completing a forced regeneration. This is to ensure that the ECU knows that the DPF and all related sensors are reset to empty. When fitting a new DPF, it is important to reset the ECU and carry out a forced regeneration. After this operation, it is advisable to look at the DPF and pipework to make sure this process has been completed.