Bosch VP30 and VP44 pumps with a PSG5 control unit were fitted to passenger cars and commercial vehicles from the late 1990s until the mid-2000s. Most of these control units have now been in service for more than twenty years, and the choice between repairing the original unit and replacing it has a direct effect on the vehicle’s reliability.
What a repair addresses
A repair replaces the failed components. The rest of the electronics — components, internal connections and solder joints — keeps its age and the wear accumulated through thermal cycling. Even a correct repair therefore does not prevent the unit from failing again through another component.
Variability in the repair market
The quality of a repair depends on each workshop’s process and controls. Manipulated, reprogrammed and uncontrolled repaired units are in circulation, and the history of a repaired unit cannot be determined from the outside.
Comparison
| Criterion | Repair of the original unit | Replacement with a new unit |
|---|---|---|
| Electronics | Original. Only the failed components are replaced; the rest retains its wear. | Entirely new. |
| Long-term reliability | Limited by the age of the unit. | All components are new, with no prior service. |
| Quality and history | Varies with the workshop and the prior condition of the unit. | New unit, coded and calibrated for the pump number. |
| Warranty | Depends on the workshop. | Two years. |
Decision criteria
A repair may be sufficient for a vehicle with limited use or a short remaining service life. Replacement with new electronics is the appropriate option when the objective is that the vehicle does not return to the workshop with the same fault — for example work vehicles, fleets and vehicles in good overall condition.
Herlic Components has repaired PSG5 control units since 2010 and manufactures the HC-PSG5, new electronics with a two-year warranty, coded and calibrated for each pump number. We offer both options and advise on each case.
References: HC-PSG5 compatibility and references. Enquiries: contact.
Herlic Components — OEM-equivalent diesel injection electronics, engineered in Europe.
