Bosch DME M 1.7 Engine ECU Repairs

Type: Bosch Engine Management
Fits: BMW 316i / 318is / 518i / 750i / 850i
Engines: E30 / E31 / E32 / E34 / E36
Year: 1990 – 1998
Ref: ECUT310195

Note: This ECU may also fit other models.

Only the name is shared when a BMW 316i and a V12 850i both run on a Bosch DME M1.7. No row on this page covers both cars, and five of the six are documented against a single model on a single chassis. Knowing you have an M1.7 tells you which page to read; it does not tell you which unit you hold.

Six references, from a 316i to a V12

Our table lists six Bosch references under this one designation. With BMW’s own number beside each, they are documented as follows:

• 0 261 200 175 with BMW 1727900: the E30 318is, on the M42 16-valve four-cylinder
• 0 261 200 520 with BMW 1739041: the E36 318i, on the M40 8-valve four-cylinder
• 0 261 200 522 with BMW 1734709: the E36 316i
• 0 261 200 950, with no BMW number printed: the E36 318is, on the M42
• 0 261 200 986 with BMW 1739648: the E34 518i, on the M40
• 0 261 200 998 with BMW 1748201: the E32 750i and the E31 850i, on the M70 V12

Small four-cylinder engines sit at one end of that list and BMW’s V12 at the other, all under a single name. The 998 row is the only one documented for the 750i and the 850i, so an owner of either car has one reference to look for: 0 261 200 998, paired with 1748201.

Why the family name leaves the question open

Two of the engines in the table appear on two rows each, and in neither case is the engine enough to pick between them. The M40 is on 0 261 200 520 in the E36 318i and on 0 261 200 986 in the E34 518i. The M42 is on 0 261 200 175 and on 0 261 200 950, and both of those rows are for a 318is.

That second pair is the clearest case on the page. An E30 318is is documented against 0 261 200 175, an E36 318is against 0 261 200 950: the same badge, the same engine family and two different units, with the chassis generation the difference between them in the records we checked. We have not recorded the E36 against the 175 row.

Put together, the badge and the chassis point to a row, and the engine adds little that they have not already told you. What confirms it is the pair of numbers printed on the DME case, Bosch’s and BMW’s, and those are what we need to see.

The row with a blank in the BMW column

One line in the table, 0 261 200 950, has nothing in the BMW number column. That is deliberate: the BMW number that belongs beside it has not been confirmed, so the cell has been left empty rather than filled with a guess.

An empty cell does not mean an unknown unit. The 950 is documented against the E36 318is with the M42, and it is on this page because we repair it. If your case carries that Bosch number, give us the label details exactly as they are printed, BMW number included, and we will work from what your unit says. Please do not look up a number to fill the space; only the one on your case helps us.

What happens to your DME in our workshop

Every unit is repaired in-house by our own engineers, in our own UK workshop and on our own equipment; none of the work is sent out. On arrival the DME is logged and inspected by eye, then tested electrically and taken through diagnostics that follow the fault you described.

When we know what has gone wrong, we contact you with the finding and a quote for the repair. Nothing chargeable is started until you have authorised it.

The repair is made at component level. The parts on the circuit board that have actually failed are identified and put right under a microscope, using temperature-controlled rework equipment, and the unit is not signed off until it passes final testing. The specific repair carried out is then covered by our 24-month warranty.

Posting an M1.7 to us

Units reach us by post from anywhere in the UK. Before the DME is packed, type the case numbers into the Repair Form, and add the model, the chassis if you know it, and a line or two on how the car has been behaving.

If the case names a DME other than M1.7, look under BMW instead. For a unit from another make altogether, begin with the marque.

All six references follow, each Bosch number with its BMW partner where one is printed, so the case can be checked against them line by line.

Common part numbers associated with this type of unit