Category Archives: Common Rail

Delphi-Common Rail System – Fuel metering calculation

The diagram shows the two-module system. On the single-module system the IDM is integrated in the PCM. 1 Pilot injection and main injection fuel quantity 2 IDM 3 PCM 4 Fuel injector 5 CKP sensor 6 CHT sensor 7 Injection signal Diesel engines normally run without the use of a throttle valve and therefore always… Read More »

Delphi-Common Rail System – Idle speed control

The fuel consumption at idle is mainly determined by idle speed and efficiency. It is advantageous to have as low an idle speed as possible, as idling is of considerable importance when driving in dense traffic (for minimizing fuel consumption). However, the selected idle speed must be sufficient to ensure that, under any conditions (e.g.… Read More »

Delphi-Common Rail System – Idle strategy

The diagram shows the two-module system. On the single-module system the IDM is integrated in the PCM. 1 Fuel injector 2 CMP signal (with older software only) 3 Injection signal (pilot injection and main injection) 4 IDM 5 KS 6 CKP sensor 7 APP sensor 8 CHT sensor 9 PCM Once the engine speed range… Read More »

Delphi-Common Rail System – Engine start strategy

The diagram shows the two-module system. On the single-module system the IDM is integrated in the PCM. 1 IDM 2 PCM 3 CKP signal 4 Separate IDM/PCM cable for transmission of the CKP signal For the engine to start, the battery voltage must be > 9V. In addition, a starter speed of 190 … 225… Read More »

Delphi-Common Rail System – Ignition ON strategy

When the ignition is switched on, the PCM is supplied with voltage and switched on via the main relay. Initially, the PCM checks all of the input signals for correct function, including those from the ECT, MAP and MAF (self-test). Afterwards the key code is checked via the PATS system. If this is OK, the… Read More »

Delphi-Common Rail System – Electric EGR valve

NOTE: After the EGR valve is replaced or after the PCM is replaced/reprogrammed, the EGR valve must be initialized using the PCM (refer to the instructions in the current Service Literature). Various versions are equipped with an electric EGR valve. The EGR rate can be metered out more accurately by the electric EGR control. Function… Read More »

Delphi-Common Rail System – Adapting the fuel injectors

Because the mechanical tolerances of the fuel injector solenoid valves change in the course of their service life, the IDM has to be adapted at regular intervals to take account of the changed fuel injector tolerances. Adaptation is done individually for each cylinder over a period of 900 seconds per cylinder. The individual adaptation processes… Read More »