Limp and listless - pressure loss in the diesel injection system


This case shows why, on an Opel Corsa D with the engine code A17DTS from the year 2007, a bad acceleration and a temporary die-off of the engine during the individual gear changes led to a somewhat longer workshop stay.
After the initial diagnosis by a technician, error P0093 "Fuel system leak detected" was read from the engine control unit's error memory. Using this fault description, the entire fuel system was checked for contamination, leakage, and even misfuelling - with no result.
The pre-feed pump also worked perfectly. No foreign bodies were detected in the fuel filter that could indicate a defect in the high-pressure pump.
Despite all efforts, no system deficiency could be found.


The solution
In some cases, the cause is a defective or blocking pressure control valve in the high-pressure pump. If the valve is mechanically clamped by particles of dirt, the correct pressure can no longer be generated in the common rail. The pressure difference is detected as a leak by the control unit.
This error also often occurs after a filter change. If the filter housing is not carefully cleaned before inserting the new filter, particles can get into the system.


Our repair tip
In this kind of case, you should remove and replace the pressure control valve. In this context, also check the valve seat and - if necessary - clean it.
Then you have to bleed the fuel system by switching on the ignition three times for 30 seconds in a row, without starting the engine.


This case can also occur on identical models with the engine code Z17DTR