Peugeot 308 T7 2.0 Hdi - software redundancy fault at the injection (level 2)

[icu12345]

So yesterday my Peugeot 308 2.0 HDI 163hp played a nasty trick on me while driving home from work. I got the “Engine fault, repair needed” message on the screen and the car went straight into limp mode. I hooked up the diagnostic cable and fired up Diagbox first thing when I got home and got this:



It is very strange, that it shows 6V battery voltage – this just cannot be. Can you give me some ideas what could trigger this error code? What is a software redundancy and what does it have to do with the motor ECU?

I wanted ti have a look at the live data, but my laptop is very old and the battery died on me almost immediately, so this is the only screen I could get. Cylinder 1 one has a longer injection time than all other injectors, but I don’t know of this is a telltale sign of anything…



I couldn't delete the fault.. It just said that the operation failed (I am going to try again today).
I just hope it is not a dead injector… Any help is appreciated, since this is the first diesel in my life Thank you

[GiveMeABreak]

Here's a description of the fault code. You can't clear the fault until the underlying cause is determined and fixed.

Fault Code:	P1621
Description of Fault:	Engine ECU: Internal fault. Possibility 1 Internal failure of the engine management ECU on the calculation of the weight of fuel present in the canister for 520 ms Possibility 2 Richness not between 0,8 and 1,2 for 520 ms Conditions of activation of the diagnostics: The following conditions have to be met - Engine ECU in partial triggering phase or in main triggering phase or in dormant phase - Engine speed above 1200 rpm
Conditions for Fault to clear:	Possibility 1 The weight of fuel coming from the canister is conform to the level calculated by the engine management ECU for at least 5,5 s Possibility 2 In the next cycle provided the richness is between 0,8 and 1,2 for 5,5 seconds.
Downgrade Modes whilst Fault is active:	Natural opening position of the motorised throttle housing Butterfly programming prohibited Limitation of engine speed Total injection cut-off Change to butterfly mode
Symptoms:	Difficult to start Stalling after starting Unstable idling Idle speed too high Lack of power Engine hesitation
Suspect Areas:	Engine management ECU Configuration of the engine management ECU Electrical harness

[icu12345]

Thank you!

The next day the car started fine, there was no warning on the display and I was able to clear the fault code.

As far as I could find out, fault injection is a term coming from software debugging and has nothing to do with the fuel injectors I was so scared about.

So, to my understanding, the error code could be triggered by a faulty ECU or a bad contact in pretty much each and every wiring harness.

So, now the car works fine but I need to figure out what happened to prevent this from happening again.

Does the implausible battery voltage shown (6V) or the fact that the car didn't know the ignition was on (IGN has three question marks) give us any clues on where to search for a loose electrical connection?