Ford Siemens SIM 24 Engine ECU Repairs

Type: Siemens Engine Management
Fits: Ford
Engines:
Year:
Fuel: Petrol
Ref: ECUT24175

Note: This ECU may also fit other models.

Our Siemens SIM24 table is a small Ford’s table. As a family, the numbers in it are on record from the petrol Ford Ka 1.3, with StreetKa 1.6 units on two rows, so knowing the car tells you very little about which row is yours. The Ford number on the label decides that.

Why the Ka alone does not find your row

The Ka is the car on record against most of the Ford numbers in our table. The StreetKa appears against two: 3S51-12A650-BE, which is on record from the StreetKa 1.6, and 5S51-12A650-DC, which is on record from both the Ka and the StreetKa with the 1.6 engine.

Naming the car therefore rules out very little. Tell us which it is by all means, and use it as a check after the match, but do not expect it to find the row.

The 1.3 is the rule, the 1.6 the exception

Where an engine size is on record for an individual Ford number, it is usually the 1.3: 1S5X-12A650-BE, 1S5X-12A650-DC, 5S51-12A650-BB, 5S51-12A650-BD, 6S51-12A650-BB and 5S51-12A650-BC. The 1.6 is on record against the two rows where the StreetKa appears, 3S51-12A650-BE and 5S51-12A650-DC.

That leaves 1S5X-12A650-BD, 1S5X-12A650-DB and 3S51-12A650-BG with no engine size on record often enough for us to state one, so neither size rules them in or out. Engine size sorts the table into likelier and less likely rows, but the match itself comes from the Ford number.

Reading the Ford number on a SIM24 label

The Ford number on the label takes the form 3S51-12A650-BG, and our table prints it without the hyphens, as 3S5112A650BG. The first four characters and the last two both matter, because the same ending turns up under more than one prefix.

BE sits under both 1S5X and 3S51, BD and DC under both 1S5X and 5S51, and BB under both 5S51 and 6S51. Mistake 5S51 for 6S51 on a BB label and you land on a different row, with a different Siemens number beside it.

Some Ford numbers are followed by a short extra code, and our table prints one on some rows, as in 5S5112A650BD 7ACD. Copy whatever follows the Ford number on your label, exactly as it appears, even where our table shows nothing after it.

What the Siemens number adds

Alongside the Ford number, the label carries a Siemens number beginning S118685 and closing with a letter. Four Siemens bases each serve two or three rows of our table, and on those rows only the letter separates one unit from the next.

The pairings on record show it: S118685001 E with 1S5X-12A650-BD and S118685001 F with 1S5X-12A650-BE; S118685004 B with 1S5X-12A650-DB and S118685004 C with 1S5X-12A650-DC; S118685003 E with 3S51-12A650-BE and S118685003 H with 3S51-12A650-BG; and S118685021 B, E and D with 5S51-12A650-BB, BD and BC.

The other two rows each have a base to themselves: S118685023 D is on record with 5S51-12A650-DC, and S118685031 B with 6S51-12A650-BB.

Nor can the letter stand alone: E closes three different bases in these pairings, and so does B. No rule ties the Siemens letter to the ending of the Ford number either, so copy the letter from your label rather than working it out.

Where our table prints a Siemens number with no letter, expect to find one on your label. There, as everywhere in this table, the Ford number makes the match and the Siemens base with its letter confirms it.

A SIM24 on our bench

Each SIM24 is repaired in-house by our own engineers, in our UK workshop and on our own equipment. The unit is logged, inspected and tested electrically, then diagnosed against the fault you report.

Once diagnosis is complete we contact you with our findings and an estimate, and no chargeable work begins until you authorise it. The fault is then repaired at component level on the unit you sent, under a microscope with temperature-controlled rework equipment, and final testing has to be passed before the repair counts as finished.

Our 24-month warranty covers that repair.

Sending a SIM24 to us

We work by mail-in only, so the unit travels to us by post wherever you are in the UK. Before it is packed, record its label on our Repair Form: the Ford number with anything printed after it, and the Siemens number with its closing letter.

Then tell us whether the car is a Ka or a StreetKa, give its engine size, and describe the symptoms you noticed.

If your Ka’s Ford number is not in this table, the Ka’s engine ECUs from other makers have a page of their own. Ford engine ECUs we cover beyond SIM24 are gathered one level up, and engine ECUs from any make besides Ford start from our main engine ECU page.

In the table below, the first column carries the Ford number and the second the Siemens number.

Common part numbers associated with this type of unit