Have a 2011 Citroen C4—1.6 diesel, 110 horsepower, 82 kW. It’s a SID 807. Use Flex ECU Chip Tuning Tool to read and write this ECU faster than find OBD.
The first tool I use is the hardware number. I research it, then go into the tuning programmer to confirm exactly which ECU I’m dealing with. If I’m unsure, I start the program, type “citroen c4 sid807”, and it shows the motor type and code.
Flex also tells me precisely which ECU is fitted to this car. If you don’t know, you can’t mess up—selecting the wrong one just means no connection, and nothing happens. We’ll read this car through OBD and write it too. You’ll see we’re using a virtual map. Okay, let’s switch off and follow the procedure.
You should have a battery maintainer. I have one, but it’s not great for this location. Anyway, we’ll read the virtual map—it downloads from the server. I’ll save this data, make the modifications, and then proceed to write it back. Let’s go from there.
Okay, reconnected to the ECU. You’ll notice the file I’m using is for start-stop. The owner wants to deactivate the start-stop feature on this car, and that’s exactly what we’ll do. I switch it off and on again, upload the file for checks and corrections. As I said, I’m writing through a virtual file. To get the original, you’d need to read this ECU in boot mode, but honestly, I don’t want to bother with that. The data size isn’t huge, but it’s not tiny either. Usually, this procedure is pretty fast with this ECU—I’ve never had issues writing it with Flex ECU Programmer.
Which programmer do you use for this type of ECU or for PSA (Peugeot/Citroen) cars?
I’ll show you where the OBD port is on this car.
You have to remove a plastic cover to access it. I’ll never understand French cars—how do they manage to hide the OBD port in such random spots? It’s here, there, or maybe on the left side—I don’t know! Citroen should just pick one place and stick with it. Honestly, it takes me longer to find the OBD than it does for Flex to write the software. Look, it’s doing the coding now—I’ll switch it off.
There, it’s off, it’s done. On older Citroens, it usually says to wait 30 seconds, but we won’t bother. I’ll set the laptop on the passenger side. I always pull the wire out from the OBD like this, disconnect Flex, and now we’ll start the car.
Okay, the car starts, and the start-stop problem is gone—no more error messages on the screen. It’s a simple job. I just wanted to show you what’s possible on the Citroen C4 with Flex ECU & TCU Programmer. I’m not sure if anyone needs this info, but I hope it’s useful.
Credits to @YOYO Diagnostic!
