Dynamic/Supply - BMW 745i Repair Instructions

- - -
BMW745iA
01 L.Jetronic Dynamic/supply
Voltage betw. leads 10 and 5
(from B
+
through double relay)
Voltage between leads 4 and 5
(from starter term. 50)
Control unit No.
0280001124 ·
>
10,8 V
<
1,0 V
. Voltage between leads 20 and 5
>
12,0 V
(from B
+
through double relay airflow meter· pump switch)
Fuel pump pressure 2.3 ... 2.7 bar
I
(vacuum hose at pressure regulator detached)
Engine speed
(Vacuum hose attached to pressure regulator)
850
±
SO/min
Test 1. Connections needed: T·plug at wiring harness and control unit, diagnosis plug, pressure
sequence: sensor
2. Input number of cylinders with ~
3. Switch on ignition (at car's ignition switch). Note voltage between leads 10 and 5.
4. Start the engine; voltage between leads 4 and 5, 20 and 5:
>
8 V. After this, voltage
between leads 4 and 5 must drop to < 1 V
5. Check fuel pressure variation by detaching vacuum hose from pressure regulator.
6. Compare with nominal values.
If nominal values are not reached : check battery, plug connections, relay and fuel pump. Carry out test steps 04 ... 08
Further information on workshop manual microfiche, job No. (troubleshooting - fuel injection system)