Citroen / Peugeot Bosch MP5.1.1 Engine ECU Repairs

Type: Bosch Engine Management
Fits: Citroen / Peugeot
Fuel: Petrol
Ref: ECUT98195

Note: This ECU may also fit other models.

The two Bosch MP5.1.1 numbers in our table, 0261204063 and 0261204066, differ by a single final digit, run on petrol and are recorded on the same two cars. The one thing that tells them apart before the label is read is the engine: a 1.8 for one, a 2.0 for the other. Below is how to tell which unit you have, and what to send us with it.

What the Peugeot 406 or Citroën Xantia tells you about an MP5.1.1

Both units are recorded on the Peugeot 406 and on the Citroën Xantia. So a 406 or Xantia owner can be confident this is the right family of unit, but the model name alone does not favour one row over the other. Treat the car as confirmation that you have the right page, then move on to the engine.

1.8 16-valve or 2.0: matching the MP5.1.1 to the engine

0261204063 is recorded against a 1.8 engine, and specifically a 1.8 16-valve. 0261204066 is recorded against a 2.0. With two rows and one size on each, the engine gives a straight either/or rather than a shortlist.

The engine size is usually easy to find before the unit comes out: the registration document (V5C) lists the cylinder capacity.

Once the unit is in your hand, the Bosch number on its label confirms the choice. If the engine size and the label seem to disagree, the label is what we work from; put the size you expected on the form so we can weigh both. If you do not know the size, the label alone will do.

Why every digit of an MP5.1.1 number counts

Because 0261204063 and 0261204066 differ only at the end, a 3 read as a 6, or a last figure worn away, turns the 1.8 unit into the 2.0 one on paper. Take the number straight off the label, in good light, all ten digits, rather than from memory or an old invoice.

A number one digit away from either of these can belong to a different Bosch unit altogether, fitted to another car. A near match is therefore not a match; if a digit is unclear, tell us which one on the form.

The Bosch MP5.1 and MP5.2 are separate units with their own numbers, so check the full name on the label as well as the number.

What to put on the Repair Form for an MP5.1.1

Our table lists these units by Bosch number. Please send every number printed on the label, meaning the Bosch number beginning 0261 and any Peugeot or Citroën number beside it, together with the car, its engine size and the fault you have noticed.

If the label names a different Bosch unit, look through the Peugeot engine ECU range we repair or the Citroën engine ECUs we work on. For a car from another manufacturer, start from the top of our engine ECU repairs.

How we handle an MP5.1.1 sent in for repair

Fill in the Repair Form, engine size and all ten digits, then post the unit to us. Our mail-in service covers the whole of the UK, so the car itself never has to travel.

On arrival the unit is logged and inspected, then electrically tested before we diagnose it against the fault you described. Our own engineers carry out the repair in-house at component level, under a microscope with temperature-controlled rework equipment, and the MP5.1.1 you sent is the one we return.

We tell you what we have found before any chargeable work starts, and nothing proceeds without your go-ahead. The unit comes back to you only after it has passed final testing, and the repair is covered by our 24-month warranty.

Both MP5.1.1 numbers appear in the table below.

Common part numbers associated with this type of unit