Voltage Values

35 Position ECU Plug:

For Terminal ID please refer to "Engine Control Module : Diagrams : Connector Views". Connector Views

GROUNDS
KEY OFF
Pin 5 to G1 0V
KEY ON
Pin 5 to G1 0 - 0.5V
Pin 5 to 16 0 - 0.5V
Pin 5 to 17 0 - 0.5V
Pin 5 to 19 0 - 0.5V
Pin 5 to 28 0 - 0.5V
This terminal is a ground on 325e, 528e, and 533i A/T only. Altitude switch on 528e, 533i, 535i 1984 only.

BATTERY SUPPLY
Pin 5 to 18
KEY OFF 11 - 13V
KEY ON 11 - 13V
Check battery voltage at battery. Battery supply on pin 18 is only applicable to 535i 1985 - 88 and 528e from March 1987 and 1988 models. Otherwise pin 18 is power from the main relay all others.

MAIN RELAY SUPPLY
Pin 5 to 18
Key OFF 0V
Key ON 11 - 13V
Pin 5 to 35
Key OFF 0V
Key ON 11 - 13V

COOLANT TEMPERATURE SENSOR
Pin 5 to 13
68°F 3.3 - 3.5V
176°F - 194°F 1.0 - 1.5V

AIR TEMPERATURE SENSOR
Pin 6 to 22
68°F 3.3 - 3.5V
104°F - 122°F 1.5 - 2.5V

FUEL PUMP RELAY
Pin 5 to 20
Key ON 11 - 13V
Cranking 0 - 1V
Idling 0 - 1V

THROTTLE SWITCH
Pin 5 to 2
Closed 0 - 0.5V
Opened 8 - 11V*
Pin 5 to 3
Opened 8 - 11V*
Full Load 0 - 0.5V
* The reference voltage may be 5V. If so, the voltages notes will be between (4.5 - 5.5).

AIR FLOW SENSOR
Pin 6 to 9
Supply 9.5 - 10.2V*
Supply (idling) 11 - 12V*
Pin 6 to 7
Load 0.15 - 0.30V
Load (idling) 0.4 - 0.65V
* The reference voltage may be 5V. If so, the voltages notes will be between (4.5 - 5.5).

OXYGEN SENSOR
Pin 24 to 23
Key ON 0.4 - 0.5V
Engine Idling 0.4 - 0.65V

ALTITUDE SENSOR
Pin 5 to 30
0 ft 3 - 5V
3000 ft 2 - 4V

ALTITUDE SWITCH
Pin 5 to 28
Below 3000 ft 11 - 13V
Above 3000 ft 0 - 0.5V