Bosch ECU: these are the differences between the ME and EDC variations

Bosch is a powerhouse when it comes to manufacturing engine management systems. If you take a look at the car park outside, there is guaranteed to be a car with a Bosch ECU in between. Since Bosch is the main supplier of ECUs, they have released quite a few different types with different names over the years. Think, for example, of the Bosch ME, the Bosch EDC and so on. But what do all those letters in those names actually mean? We are happy to explain it to you!

The origin of the letter 'M'

If you dig into the history books, you will notice that Bosch pioneered the development of electronic controls in cars very early on. They already claimed revolutionary patents (for that time) in the 1960s, which eventually resulted in the Bosch D-Jetronic.

It was not until the 1980s that a type followed that you can more and better compare with the more modern ECU: the Motronic. It was Bosch's first digital engine management system that could control all important parameters in the engine. The Motronic was first used in the BMW 7-series, but brands such as Volkswagen and Volvo also saw the benefits and quickly followed suit.

Several series of the Motronic ECU followed, such as the Motronic M1.1, M2.5 and ML4.1. And now, years later, the letter 'M' can still be found in the serial numbers that Bosch makes for its ECUs for petrol engines. This can all be traced back to the name ‘Motronic’ hat Bosch introduced at the time!

The ME series and its variants

But… Since the introduction of the Motronic, different functionalities have been added, haven't they?” That's right! And that's exactly why Bosch adds several letters after the 'M' for such an important function. One of the most important that you will find in all 'modern' ECUs from Bosch is the letter 'E'. The 'E' stands for ‘Electronic Accelerator’. A well-known example of the Bosch ME series is the ME7.4.5, which has been used in several PSA cars such as the Citroën C4 and the Peugeot 307.

Over the years, three variants of the ME series have been made. The first variation on the ME series is the Bosch MED ECU. The 'D' in this case stands for ‘Direct Injection’. A well-known example of this series is the Bosch MED9.5.10. This ECU can be found, for example, in VAG models with a 1.6 FSI engine such as the Audi A3 8P, Volkswagen Golf 5 and the Skoda Octavia 1Z.

The second variant of the Bosch ME line is the Bosch MEV. However, don't get too distracted by the meaning of the letter 'V'. The 'V' is the abbreviation of Valvetronic (VVT), a name mainly used by BMW. However, the MEV series is also used for engines from other car brands that have variable camshaft timing. The most famous of these is the Bosch MEV17.4 that PSA used in combination with the 1.4 and 1.6 VTI engines. The Peugeot 207 and Peugeot 308 are the two cars in which this ECU can often be found.

Finally, there is the MEG series. The most famous example of this is the Bosch MEG1 used in the Smart ForTwo. This ECU not only controls the engine, but also controls the transmission. The 'G' in this case stands for ‘Gearbox’.

Diesel Engine ECUs: The EDC Line

Now that all the variations on the petrol engines have been discussed, it is also interesting to take a look at the diesel engines. Because although you may think that diesel engines are being phased out, about 15% of the European vehicle fleet still consists of cars with a diesel engine. Interesting fact: despite the fact that there are many more cars with petrol engines on the road, it does not mean that the diesel ECUs are sent in for remanufacturing much less often. The diesel ECUs are in fact sent in more often than the M (petrol) ECUs. These Bosch diesel ECUs can be recognized under the series name 'EDC'. EDC stands for ‘Electronic Diesel Control’. Bosch has also developed several variations in this line of diesel ECU. We will therefore briefly review these.

Where the first letter of the word was used for the petrol engines to indicate the meaning, the situation is different with a number of EDCs. For example, the 'V' of the Bosch EDC15V that can be found in the Seat Ibiza 6K1 and Volkswagen Caddy MK2 stands for ‘Injection Pump’. Another example is the letter 'U'. With the Bosch EDC16U1, the 'U' stands for ‘Pump Nozzle’. Deze ECU is overigens in combinatie met 1.9 TDI en 2.0 TDI motoren tussen 2003 t/m 2009 gebruikt. This ECU was used in combination with 1.9 TDI and 2.0 TDI engines between 2003 and 2009. In addition to the 'U', Bosch also uses the letter 'P' to indicate the Pump Nozzle functionaliteit. The best-known example of this is the Bosch EDC15P(+), which is also only used with VAG models.

We only have one abbreviation left and that is perhaps also one of the most common letters. It concerns the 'C', which stands for ‘Common Rail’. This type of ECU is able to control engines that use Common Rail technology: A system in which the fuel is equally distributed over the injectors via a central supply rail. Examples of Common Rail engines are the well-known TDCI, JTD and CDI engines. The Bosch EDC16C36 is an example of such an ECU and has been applied to the Opel Zafira B with CDI engine and the Fiat Ducato with Multijet (JTD) engine.

Now you may be wondering whether all those different letters can also be used in combination with each other. The answer to that is: Yes! A good example is the Bosch EDC16CP33, which has both Common Rail and Pump Nozzle functionality. This ECU is applied to 2.0 CDTI engines, which can be found, for example, in the Vauxhall Vivaro and Renault Trafic.

Hopefully we have now been able to bring some order to all the different Bosch ECU names! If you have a Bosch ECU that shows certain complaints, please feel free to contact us. Perhaps one of our ECU remanufacture solutions can solve the problem.