Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hi guys
2019 Citroen Relay van 2.0 blue HDI common rail diesel.
Van is non runner with no power going to coils. No fault codes present.
It has cam and crank signals which show as synced and shows immobiliser ok on live data. Cranking fuel pressure is same as requested, possibly a little higher but I'm guessing this is because injectors aren't opening.
Powers and grounds all good.
Any suggestions what other inputs if any are required for injectors to be powered?
Thinking ECM but this is a big call as replacement is over £1000. Can't find anyone capable of testing ECM in UK (Delphi DCM6.2 C).
Thanks in advance.
By coils do you mean the common rail injectors? If so, then what I think you are saying is that you do not see any power going to the common rail injectors. But then you say power and grounds are all good.
To answer your question we really need to understand how the injector amplifiers are designed. If they have a constant supply voltage, then the injector amplifier control would use this regulated voltage as a current source to pick and hold the injectors during actuation. However, the supply voltage could also be regulated to different driver reference voltages depending on engine mode.
This is very confusion because you say the ECM does not light the MIL or have any DTCs. In the diesel controller the injector drivers and the injectors they control have full coverage diagnostics. So, the question is can you communicate with the ECM using a scan tool? To have a failure in the injector amps and not generate a DTC means the module power supply is completely dead. If so, I would expect no communication over the DLC and the engine exhibit a no start. If you can talk to the module and it still disables the engine, lets say due to security, I would expect a DTC or some dash indication to be shown.
