Guide To DIY Remapping Your Peugeot 306 HDi

Read this before attempting to ‘remap’ or flash your Peugeot 306 HDi using a ECU flashing tool such as a KWP2000+ or Galletto 1260. If you're unsure which tool to buy, check out our review of the KWP2000+. Failure to follow these pointers may result in bricking your ECU which means the car will not run at all. This will require a professional to fix and is a whole lot of hassle which can be easily avoided.

There are now many businesses which offer a DIY option for remapping your HDi at home with the use of a low-cost ecu reader/writer. The process is often that you read the original data from the ECU and send it to the tuner via email (these files are very small), they will then make the necessary adjustments and send it back to you. All that needs to be done is to upload (write) this new file to the ECU and your 306 HDi is remapped.

In basic terms imagine your cars ECU is a USB drive with the map data file on it. Connecting an ecu reader/writer such as the KWP2000 or Galletto 1260 via the OBD port under the steering wheel allows you to copy or read this data file to your computer and also overwrite it.

In a nutshell - if anything goes wrong during the writing process (when you are overwriting the existing map file) there is a very high chance you will corrupt the file and the ECU will be bricked. The clue is in the name here as if this happened your ECU is about as useful as a brick (although there are ways out of this which I will cover in another post).

5 steps to reduce the risks:

  1. Plug the laptop into the mains do not run it from the battery.
  2. Disable the laptops wireless adapter.
  3. Make sure the battery is healthy, fully charged and turn off anything that runs on it e.g. headunit, headlights.
  4. Close all non-essential programs on your laptop - you want the laptop to be as stable as possible.
  5. Disable any automatic updates or anything which is likely to pop-up and interrupt the writing process.

You will need to follow the instructions which came with the ECU flash tool for an exact guide of how to remap Peugeot 306 HDi but the above points are still important.

Do not touch any free maps which either come with your ECU flash tool or you find floating around the internet. Similarly, discs packed with 5,000 maps for £9.99 are best avoided. For the cost of a remap from a reputable hdi tuner it is not really worth the risk.

Please note I am not an expert and cannot be held responsible for any damage resulting from following the advice on this page.


  1. Do you know somebody that you could recommend doing the mod of my org file ?

    1. Has a very good reputation on owners club forums.

  2. Hi, do you have a link to a reputable hdi tuner who can remap my file ?

    1. Hi, Steve at has a good reputation for doing hdi remaps. He can give you a personalised map for your requirements e.g. economy, performance.

      Is this for a 306 2.0 HDi?

    2. No it is for two Citroen C5 ´01 and a Xsara ´04 all RHZ, EDC15c2. I have contacted him, and read his homepage it look very good. Now I just have to buy a Galletto 1260 and dump the ori file from the cars :-)

      Nice artikel you wrote by the way ;-)

      Sorry for my english, im from Denmark.

  3. Hi guys,

    Just came across this whilst looking for something else but thought it would be worth posting on here: I can repair an ECU once it's bricked and I only charge £50 which includes return postage, this means there's really not that much to worry about when flashing your car, other than the fact you could be without a car for 2-3 day.

    In reality this only happens about 1 to 2 times a year and we sell hundreds of remaps, since I've been advising customers to use the MPPS tool rather than the Galletto or KWP I've actually seen no problems at all.

    Steve (HDI Tuning)