BMW 1989-1995 525i Service Manual page 189

FUEL INJECTION-DME
Table e. ECM Pin Assignment-DME 1.3
130-21
Pin Signal Component/func tion
I
Signal
1
I
output
Ignition coil Ignition coil primary control
- -
2 I ground Ground
I
Chassis ground
.-
-
3
10uiPut
Fuel pump relay control Fuel pump relay switches with engine running or cranking (crankshaft
I
pos ition signal must be present for relay to switch)
-
4
output
Idle speed con trol
I
Pulsed ground (duty cyc le) close signal (see also termina l 22)
I
(vacant on 535i model with EML )
I
5
I
output
Evaporative purge valv e control Pulsed ground (mapped) with engine running at normal tempe rature and
varying engine load
6
I
output
Engine speed RPM signal 1 0 instrument cluster
7
I
input
Volume air flow sensor Voltage signal from volume air flow sensor (0·5 VDC . var ies with engine
load )
8
I
input
Cylinder identification Voltage pulse (VAC) between pin 8 and pin 31 when cylinder no. 6 fires
(for ignition control)
9
I
vacant
-
-
10
I
Oxygen sensor
1
Ground for oxygen sens or sign al
11
I
vacant
-
1-
12 output
Volume air flow sensor
1
Voltage supply (5 VDC) to volume air flow sensor
13 input
1
Diagnostic connector (A xD)
I
Diagnostic RxD (receive) signal to pin 15 in data link connector
14 ground
Fuel injectors
I
Ground for fuel injectors cuto ut stage
15 output
I
Check Engine
I
Check engine lam p control
16 output
I
Fuel injectors. cy!. 1.3.5
I
Pulsed ground (injection pulse width in ms)
17 output
I
Fuel injeC1ors. cy!. 2. 4, 6 Pulsed ground (injection pulse width in ms)
18 input
I
Power supply (terminal 30 )
I
Battery voltage (B+) at all times (terminal 30 )
19 ground
I
Shielding ground
1
Ground for ECM and sensor shield ing
20 vaca nt
I-
I-
2 1 vacant
I-
I-
22 output
Idle speed control Pulsed ground (duty cyc le) open signal (see also ter mina l 4)
(vacant on 535i models with EML )
-
23
vacan t
1 -
-
24
ground
I
Output stage ground
Ground for out put stages other than
injectors
and ignition
25 vacant
1 -
-
26
I
ground
Volume air flow sensor Ground for volume air flow sens or
27
I
input
Power sup ply (terminaI15)
Battery voltage (B+) with key on or engi ne running (terminal 15)
28
I
input
Oxygen sensor Oxygen sens or signal wire (0·1 VDC fluctuating with engine running)
29
I
input
Vehicle speed Vehicle speed signal from instrument cluster
(vacant on 535i model with EML)
30 vacant
-
-
31 input Cylinder identification sensor Voltage pulse (VAC) between pin 8 and pin 31whe n cy!. no. 6 fires (for
ignition control )
32 output
I
Fuel consumption (ti) Fuel consumption output (KVA signal) to instrument cluster
33
vacant
i-
I-
34
vacant
I-
I-
35 vaca nt
1 - -
36 output
Main relay
I
Main relay activation (relay term inal 85)
37 input
I
Main relay
I
Voltag e supply from main relay to ECM (relay terminal 87)
38 input
I
On -board computer
I
Drive -away protection ena ble
continued on next page
ECM PIN ASSIGNMENTS