Citroen / Peugeot Bosch MA3.1 Engine ECU Repairs

Type: Bosch Engine Management
Fits: Citroen / Peugeot
Fuel: Petrol
Ref: ECUT94195

Note: This ECU may also fit other models.

“Citroën Saxo 1.1, Bosch MA3.1” describes the car and its engine ECU accurately, and on this page it still leaves all four units in play. Every row in our table is recorded against both the Saxo and the Peugeot 106, and the one row not recorded with the 1.1 has no engine size on record at all, so nothing in that description rules it out.

The useful work therefore splits in two: what you can confirm while the ECU is still in the car, and what only the unit can tell you once it is out. The sections below take them in that order, then cover what to send and how the repair is carried out.

What the car confirms with the ECU still fitted

Make, model and engine size can all be checked before the unit is removed, and for a Bosch MA3.1 they answer one question well: whether this is the right page. A petrol Saxo or 106 with an MA3.1 fitted points here, and sellers list all four of these units under that name, sometimes written MA 3.1.

What they cannot answer is which of the four you hold. Three rows, 0261203736, 0261204622 and 0261204788, are recorded with the 1.1 petrol engine. The fourth, 0261204625, has no engine size on record, so a 1.1 does not set it aside, and the car name is the same on all four. Once the car has pointed you to this page, choosing the row falls to the label.

What the label settles once the unit is out

With the ECU in your hand, the Bosch number on its label is the detail that separates the rows. All four begin 0261; one continues 0261 203 and three continue 0261 204, and the final three digits do the rest.

Two of them are closer than they look. 0261204622 and 0261204625 differ only in the last digit and are recorded against the same two cars, yet they are separate rows in our table, so a label read in a hurry can lead to the wrong one. Read every digit from the unit itself, and treat a spaced form such as 0 261 204 625 as the same number.

If the Bosch number on your label is not among these four, look for it elsewhere in our range. The Peugeot engine ECU index and the Citroën engine ECU index list the other designations we repair for each marque, and a car from a different manufacturer is covered under engine ECU repairs for every other make.

Where the Peugeot or Citroën number helps

It is common for the label to carry a Peugeot or Citroën number as well, beginning 96. Two rows in our table show one beside the Bosch number: 96 203 989 80 with 0261203736, and 96 315 287 with 0261204788.

On the label, that second number is printed as 96 315 287 80; the table’s cell shows its first eight digits. Where the 96 number on your unit matches the one beside your Bosch number, each confirms the other.

The other two rows, 0261204622 and 0261204625, have no number in that column, so for those the Bosch number is matched on its own. Send any other number your label shows regardless; we use every number on it when we confirm the unit.

What goes on the form, and when to fill it in

Complete the Repair Form once the unit is out, copying from the label with the unit in front of you: the full Bosch number, any 96 number, the car, the engine size and the fault you have noticed. Working from the unit rather than memory avoids the one-digit slip described above.

Then post the ECU to our workshop. Everything happens by post, so where in the UK the car sits makes no difference.

Inside the workshop, from arrival to final test

Each unit is logged on arrival, inspected, and tested electrically before our engineers work through diagnostics aimed at the fault on your form. The repair is made in-house at component level: the part that has failed is found and repaired under a microscope with temperature-controlled rework equipment, and it is your own unit that comes back.

You hear our findings before any chargeable work starts, and nothing goes ahead without your authorisation. A unit leaves only once it has passed final testing, and the repair carried out is covered by our 24-month warranty.

The four Bosch MA3.1 numbers are listed below, with the Peugeot or Citroën number where the table holds one.

Common part numbers associated with this type of unit