Friday 17 December 2021

BMW E30 / E28 Diagnostic Plug / Socket Pin Out Diagram

11.5BrownGround Distribution G101
40.5Brown / VioletGauges / Warning Indicators,
Coolant Temperature Sender
50.5White / GreenFuel Control,
Injector Control Module (Fuel Rate)
70.5White / BlueService Indicator,
Service Interval Processor (Reset)
112.5Black / YellowStart, Start Signal
120.75BlueCharge System, Alternator,
130.75BlackIgnition, Ignition Coil
142.5RedCharge System, Alternator
151.5Green / YellowIdle Speed Control,
Idle Speed Control Unit

BMW E30 Fuse Box Layout + Diagram


17.5AHeadlights (also 2, 13, 16)
27.5AHeadlights (also 1, 13, 16)
315AAuxiliary Fan (also 18)
415ALights: Turn/Hazard (also 24)
525AWiper / Washer
825ALights: Dash, Rear Defogger, 
Seatbelt Warning (also 10), 
Speedometer / Indicators (also 12)
915AIdle Speed Control / Vacuum Advance,
Reverse Lights
107.5ASeatbelt Warning (also 8), 
Service Indicator (also 24), 
Tachometer / Fuel Economy Gauge (also 24), 
Gauges / Indicators, Brake Warning system,
1115AFuel Delivery
127.5ARadio (also 21), 
Speedometer / Indicators (also 8)
137.5AHeadlights (also 1, 2, 14)
147.5AHeadlights (also 1, 2, 13)
15-Not used
16-Not used
1715AAccessory Connector
1830AAuxiliary Fan (also 3, 19)
197.5AAuxiliary Fan (also 3, 18), 
Interior Lights (also 21, 22, 27), 
Power Mirrors
2030AHeater / Air Conditioning (also 28)
217.5AAuto-Charging Flashlight, Digital Clock, 
Glove Box Light, Ignition Key Warning,
Interior Lights (also 14, 22, 27),
Radio (also 12), Trunk Light
227.5AInterior Lights (also 19, 21, 27),
Lights: Front Park/Tail, 
Front Side Marker
237.5ALights: Dash, Front Park/Tail, 
Front Side Marker, 
Rear Marker / License Plate
2415ALights: Turn/Hazard Warning (also 4), 
Tachometer / Fuel Economy Gauges (also 10), 
Service Indicator (also 10)
2525ANot used
2625ANot used
2725AInterior Lights (also 19, 21, 22),
Central Locking
2825ACigar Lighter, Power Antenna
297.5AFog Lights
307.5AFog Lights

Thursday 9 December 2021

E30 Speedometer Schematic / Wiring Diagram / Pinouts

 ** For E30 speedometer / odometer troubleshooting and repair guide see THIS POST. **

The arrangement is the same with both VDO and Motometer type gauges. 

Pins are: 

R - 12v +

31 - Ground

31b - Speed sensor INPUT Pin 1

A - Speed sensor Pin 2 *NOT USED*

Bench testing can be achieved by powering the unit with 12v and simulating the pulse of the speed sensor over the two remaining pins, either way around. This is essentially done by creating a pulse across the circuit of pin A and A1. You can do this by just bridging the two pins together with a piece of wire and touching the wire against one of the pins on and off to make the ‘pulse’, as this is basically how the speed sensor works, but simulate any kind of actual road speed you will need to be doing the on/off pretty quickly. A far better way to bench test is to use some kind of ‘pulse-generator’, such as an oscilloscope or something set up using an Arduino, which is what I used to create a pulse with 5 volts. I will post a guide soon.

E30: Rebuilt and refitted instrument binnacle w/ new speedo/odo + more

  • Replaced speedometer / odometer.
  • Replaced back-light bulbs.
  • Checked and tested Si batteries.
  • Tightened brass-nut on temperature-gauge.
  • Bench-tested.