ECU
The ECU is the brain of your E30. It is responsible for controlling all aspects of Engine Management.
Contents
Overview
From the first carburetted M10 engines to the sophisticated M42, all E30s features some form of Engine Control Unit that controlled the Fuel system. Over time the systems became more advanced and incorporated Cold Start, Ignition timing and idle speed. They did this by tapping into a variety of sensors, such as the AFM, CPS, CTS, and TPS.
Based on a fuel map inside the main ECU chip, the system could then control the correct fuelling right across the engine rpm, load and temperature range.
List of ECUs
The following list shows which ECUs were fitted to which vehicles:
| ECU Number | System | Models | From/To |
|---|---|---|---|
| 0260 200 005 | Carburettor | 316 | 1982- |
| 0280 000 318 | L-Jetronic | 318i | 1983 - 84 |
| 0280 000 330 | L-Jetronic | 318i | 1984 - 87 |
| 0280 001 301 | L-Jetronic | 320i and 323i | 1982 - 84 |
| 0280 001 309 | L-Jetronic | Later 320i | |
| 0280 001 308 | L-Jetronic | Later 323i | |
| 0280 000 310 | L-Jetronic | Late 323i | |
| 0261 200 174 | Motronic | 316i | 1988 Onwards |
| 0261 200 157 | Motronic | 318i | 1987 - 88 |
| 0261 200 175 | Motronic | 318iS | 1989 onwards |
| 0261 200 152 | Motronic 1.1 | 320i | 1987 |
| 0261 200 381 | Motronic | 320i | 1987 onwards |
| 0261 200 172 | Motronic | 320i | 1987 |
| 0261 200 087 | Motronic | 320iS | |
| 0261 200 073 | Motronic 1.0 | 325i Chrome bumper | 1987 |
| 0261 200 153 | Motronic 1.1 | 325i Chrome bumper | 1987 |
| 0261 200 173 | Motronic | 325i Plastic bumper | 9/87 onwards |
| 0261 200 164 | Motronic 1.3 | 325i Auto | 9/87 onwards |
| 0261 200 380 | Motronic | 325i | 8/88 onwards |
| 0261 200 071 | Motronic | Early 195/200bhp M3 and Evo 1 | |
| 0261 200 090 | Motronic | M3 Evo II | |
| 0261 200 091 | Motronic | M3 with 215bhp | |
| 0261 200 092 | Motronic | M3 Sport Evo | |
| 0261 200 042 | Motronic | 325e | until 9/85 |
| 0261 200 154 | Motronic 1.1 | 325e | 1987 |
| 0261 200 074 | Motronic | 325e | 9/85 onwards (Low compression) |
Pinouts
Main article: ECU Pinouts
The ECU for each engine management system is differentiated by the size of its plug. Jetronic systems used a 25-pin system, Motronic 1.0 used a 35-pin system, and Motronic 1.1 and 1.3 used a 55-pin plug. The increasing number of pins demonstrates the increasing complexity of the systems, which is why we've compiled pinout charts, to help you diagnose any of your engine management issues.
