Engine Control Module

35 Position ECU Plug:

CONNECTOR VIEW

SYSTEM
- Motronic

LOCATION
- Glove box

TERMINAL ID
1 - Output to coil (-) control (Blk)
2 - Closed throttle input (Brn/Blu)
3 - Full Load throttle input (Brn/Blk)
4 - Starter solenoid input (Blk/Yel)
5 - Chassis ground (Brn)
6 - Air flow sensor ground (Grn/Brn)
7 - Air flow sensor load input (Grn/Yel)
8 - Engine speed sensor (+) (Blk)
9 - Air flow sensor supply (Grn/Wht)
10 - Ground (M/T) (Brn), P/N (A/T) (Brn/Grn)
11 - Injector control pulse width output (Wht)
12 - Diagnostic
13 - Coolant temp. sensor input (Grn/Red)
14 - Injector(s) 1, 2, 3 control (Brn/Wht)
15 - Injector(s) 4, 5, 6 control (Brn/Yel)
16 - Chassis ground (Brn)
17 - Chassis ground (Brn)
18 - Main relay (Red/Blu) /Battery(+)(Red)
Main relay for 528e, 533i & 535i models up to and including 1987 years. Battery(+) 535i 1985 - 88 and 528e from March 1987 and 1988 models.
19 - Chassis ground (Brn)
20 - Fuel pump relay control (Grn/Brn)
21 - Engine speed output (Blk/Blu)
22 - Air temperature sensor input (Grn/Vio)
23 - Shield ground
24 - Oxygen sensor (Grn)
25 - Mark sensor (-) input (Yel)
26 - Mark sensor (+) input (Blk)
27 - Engine speed sensor (-) (Yel)
28 - Transmission range switch (NT) (Brn/Blk)
This terminal is a ground on 325e, 528e, and 533i A/T only. Altitude switch on 528e, 533i, 535i 1984 only.
29 - A/C on input (Blu/Blk)
30 - Barometric sensor input (Wht)
31 - Oxygen sen. heater relay ctrl. (Grn/Brn)
32 - NO CONNECTION
33 - ISC valve control (Wht/Yel)
34 - ISC valve control (Wht/Grn)
35 - Main relay power input (Red/Blu)

Notes
The 528e Models changed to a 55 pin connector in March 1987.

If there is a question as to whether the system has idle speed controlled by the motronic ECU or not, check to see if there are wires in pin 33 & 34. If no wires then idle speed is controlled by a separate VDO control unit.