Citroen / Peugeot Bosch MP5.2 Engine ECU Repairs

Type: Bosch Engine Management
Fits: Citroen / Peugeot
Fuel: Petrol
Ref: ECUT99195

Note: This ECU may also fit other models.

Our Bosch MP5.2 table reads best as two separate lists that share a name. Seven of its fourteen units are recorded against the Peugeot 406, three of them against the Citroën Xantia as well, and six more against the Peugeot 106, the Peugeot 306 or the Citroën Saxo; on our records, no row carries a car from both lists. The model you drive tells you which list to read, and the label finishes the job inside it.

Which Bosch MP5.2 list your car belongs to

The model on the car does the sorting. A Peugeot 406 or a Citroën Xantia sends you to the first list: 0261203811, 0261203815, 0261204651, 0261204695, 0261204696, 0261204697 and 0261204832. A Peugeot 106, a Peugeot 306 or a Citroën Saxo sends you to the second: 0261203912, 0261203913, 0261204628, 0261204629, 0261204652 and 0261204689.

Engine size follows the same line, with one exception. Every first-list row with a size on record is a 2.0, and three of the four second-list rows with a size on record are 1.6. The fourth is 0261204652, a 306 with a 2.0, so a 2.0 engine alone does not tell you which list you are in. The car does.

The fourteenth unit, 0261204082, belongs to neither list. We hold no car or engine size for it, so it has a section of its own further down.

Seven MP5.2 rows recorded on the Peugeot 406

The first list is where the car does the least. A 406 owner starts with all seven rows, and the engine size cannot trim them: four carry a 2.0 and the other three have no size on record, so on our records a 2.0 rules none of them out.

A Xantia gets you further, to three rows: 0261204651, 0261204695 and 0261204697. All three are recorded against the 406 too, so the Xantia narrows the 406 list rather than opening a separate one.

Our table lists these seven by Bosch number only, which puts the weight on those ten digits, and here they sit close together. 0261203811 and 0261203815 differ in their last digit alone, and 0261204695, 0261204696 and 0261204697 run in sequence. A misread figure would leave you on a plausible 406 row that is still the wrong one.

That is why a 406 owner gains most from sending every number on the label: the car has already done all it can.

How far the 106, 306 and Saxo narrow an MP5.2

The second list answers the car far better. Of its six rows, a Peugeot 106 is recorded on two, 0261203913 and 0261204629, and a Citroën Saxo on three, 0261203912, 0261203913 and 0261204629.

The Peugeot 306 appears on four: 0261203912, 0261204628, 0261204652 and 0261204689. It is the one car on this page with two engine sizes on record, and that helps. Among its rows with a size recorded, a 1.6 leaves 0261203912 and 0261204628, and a 2.0 leaves 0261204652. 0261204689 is a 306 with no size on record, so whichever engine your 306 has, that row stays in play alongside the sized ones, and the label chooses.

This list also holds the three units our table pairs with a Peugeot or Citroën number. 0261203912 is listed with 96 236 759 and 0261204652 with 96 304 024; on the label both are printed with a trailing 80, as 96 236 759 80 and 96 304 024 80. 0261204689 is listed with 96 297 670 80. On any of these three, either number leads to the right row.

Two pairs here sit a digit apart and cross a change of car. 0261203912 and 0261203913 differ only at the end, as do 0261204628 and 0261204629, and in each pair the first is recorded on the 306 and the second on the 106. That makes the car a fair check on a worn final digit, except for a Saxo and the first pair, since the Saxo is recorded on both of those units.

0261204082, and the one digit that crosses between MP5.2 lists

0261204082 is an MP5.2 we list with no car or engine size on record. If yours carries that number, the Bosch number is the only thing placing it, so copy it straight from the unit with extra care.

One pair of neighbours deserves a mention because a single digit carries you from one list to the other. 0261204651 is recorded on the 406 and Xantia, 0261204652 on the 306, and both are recorded with a 2.0. The engine size will not catch a slip between them, but the car will.

Outside this table, a Bosch number one digit away from any of these fourteen can belong to a different unit entirely. The Bosch MP5.1 and MP5.1.1 are separate units with their own numbers, so read the full name on the label as well as all ten digits.

What to put on the Repair Form for a Bosch MP5.2

Give us the car first, because it tells us which list to start in, then its engine size and the fault it shows. After that, copy every number on the label from the unit itself: the Bosch number beginning 0261 and any Peugeot or Citroën number printed beside it. If a figure is scuffed or faded, tell us which one rather than filling the gap with a guess.

If the label names a different Bosch unit altogether, look where the Peugeot engine ECUs are gathered or in the equivalent collection for Citroën. For a car from any other maker, use the main engine ECU repairs listing.

What happens to your MP5.2 in our workshop

Fill in the Repair Form, model name at the top, and send the unit by post. We run a mail-in service for the whole of the UK, and the ECU is the only part that needs to come to us.

Each unit is logged when it arrives, looked over and tested electrically, then diagnosed against the fault on your form. The fault is traced to the component responsible and repaired there by our own engineers in our UK workshop, working under a microscope with temperature-controlled rework equipment. Your own MP5.2 goes back to you once the work is done.

You hear what we have found before any chargeable work starts, and nothing proceeds without your authorisation. A repair counts as finished only when the unit has passed final testing, and it is covered by our 24-month warranty.

All fourteen Bosch MP5.2 numbers are listed below, with the three Peugeot and Citroën numbers our table holds.

Common part numbers associated with this type of unit