PSA/Citroen/Peugeot Electric - Energy Saving Mode

Hello from Zurich to the Can Hacker community!

Ich fahre einen neuen Citroen C4 und ärgere mich wie sehr viele andere Besitzer von PSA-Fahrzeugen über die Bevormundung durch den sog. EEnergy saving mode.

After a maximum of 30 minutes in a parked vehicle with the engine off, almost all electrical consumers are disconnected from the power supply! This is particularly annoying: the radio/navigation/telephone system stops working, and only starting the engine resolves the issue. Then, the rule applies: 5 minutes of idling = 10 minutes of listening to the radio, even though the battery is fully charged.

Currently, a CAN command from the main control unit (ECU) disables the radio system, but the B+ voltage remains active. Therefore, a constant positive power supply line is already in place.

I would now like to monitor the so-called 'Comfort Bus' (which includes features like radio, window lifters, interior lighting, etc.), intercept the shutdown command, and potentially send a counter-command to re-enable the radio. According to the manufacturer, this bus operates at a low speed of 125 kBps.

Using a CAN bus analyzer from Microchip, along with a netbook and CANHack 2, a brief flurry of chaotic data is observed, followed by the system freezing up.

Meine Fragen: 1. Hat ein Forum-Experte Erfahrung mit diesen Eigenheiten frz. Cars?
What kind of computer (processor, clock speed) is required for this application?
Is there any chance at all of outsmarting the system?

Thank you in advance for your comments. Best regards, Citrofan.

Hello,

Theoretically, it should be possible with a microcontroller that has two CAN interfaces and is connected to the CAN bus before the radio.
Whatever data arrives at one CAN interface is passed on to the other. "Bad sleep messages" can be filtered out, and potentially missing "stay awake" messages can be added by the radio side.

I would first try to get the radio working without using the CAN bus connection from the vehicle.
It starts up and runs smoothly: It seems the car is sending a "sleep" notification.
"It turns on and runs for only 30 minutes: The car is not displaying the "stay awake" message."
It's not possible to play the logged trace data from the car (with the radio disconnected) directly on the radio and see which ID it reacts to.

Best regards, Rainer.

Thank you very much for the quick and interesting response.

I've acquired a fast laptop and I'm going to try out some things with it.

Unfortunately, the radio won't work without the exact chassis number of the vehicle. This number is transmitted upon startup and unlocks the radio if it matches the number stored in the radio. The radio, along with the entire associated information module, displays various other messages from the car. The data traffic is quite high. However, it might be possible to cut the CAN bus lines shortly before shutdown to disconnect it from the control unit...
I will get back to you when the initial results are available.

Best regards,
Yule.

Quote:

Unfortunately, the radio will not work without the exact chassis number of the vehicle. This number is transmitted upon startup and then unlocks the radio if the same number is stored in the radio's memory.

What prevents you from recording the corresponding messages and then playing them back?

Unfortunately, I haven't gotten that far yet! While I can now list a few messages with some effort using the Microchip CAN analyzer and its software, all the data fields are empty. The can tool software doesn't work; I can't connect it to the USB module.

What other hardware and/or software is available for sniffing data? Nothing is working through the OBD port, so I've tapped into the CAN+ and CAN- lines between the radio and the control unit.

It seems there's still a long way to go...

Hello,

Quote:

I can now, with some effort, list a few messages using the microchip CAN analyzer and its software, but unfortunately, all the DATA fields are empty.

Hmm?

So, I would say that empty CAN messages are quite rare and also a bit pointless.

Is the configured bitrate correct? If so, either your tool is not working properly, or you have swapped CAN-H and CAN-L (in which case no messages should be received at all).
Have you tried it with or without a 120-ohm termination resistor?

Hardware and software package that works.
https://shop.dieselschrauber.de/rks-can-interfaceadapter-usb-auf-can-p-313.php

Best regards, Rainer.

That's a great service, thank you!

Yes, I've tried all the bitrates already, and with or without a terminating resistor, I've swapped the positive and negative connections, and I've even looked at it with an oscilloscope...

I also have an AGV4000B, and I've connected the two CAN lines, but I don't have any software that could provide clarity on this matter (Modiag).

Ich würde nun gerne einen Versuch mit Deinem Interface machen, bräuchte aber evtl. zusätzlich eine OBD-Buchse wo ich dann bequem und sauber die + und - CAN abzweigen kann. Aufpreis dafür bezahle ich gerne. Wiemuch?

As I mentioned, the standard OBD system on the Citroen only displays a few readings like coolant temperature, intake temperature, speed, etc. There's nothing else available there.

Best regards.
Yule.

I might still have some OBD2 sockets available, but I offer them without any guarantee.

Quote:

According to the manufacturer, the bus is a low-speed bus with a data rate of 125 kB

.



P.S.: The radio typically does NOT connect to the CAN drive (high-speed) but rather to the comfort-CAN bus. This means that different wires are used in the wiring harness!

I'm moving this topic to the correct section.

Sure, that's my mistake! Sorry!