NOTE: If the IDM has been programmed with the latest software version using WDS, ensure that the PCM is programmed with the latest software version as well. If this was not done automatically at the re-programming stage, then it must be done manually immediately. Otherwise increased combustion noise, increased fuel consumption and black smoke emissions may result.
NOTE: When re-programming the IDM, ensure that the correction values for the fuel injectors are also entered. If this is not done, then it is not possible to start the engine afterwards.
The IDM is an intelligent fuel actuator. It processes information on the injected fuel quantity and injection timing from the PCM and actuates the fuel injectors accordingly.
The following sensors are connected directly to the IDM:
• Fuel temperature sensor,
• Fuel pressure sensor,
• BARO sensor.
Some of this information is made available to the PCM via the CAN data bus for injection calculations. However, the engine speed signal, which has already been digitized by the IDM, is sent directly to the PCM via a separate cable. This is because the engine speed signal has high priority, as it is used for calculating the injected fuel quantity and the injection timing.
The BARO sensor is integrated in the IDM and is used to adapt the boost pressure and injected fuel quantity. However, the BARO sensor is only used in the calculations if a variable geometry turbocharger is installed.