BMW E36 Guide

BMW E36 (1990 - 1999)

RPM

Use the wire connected to the instrument cluster #20, black wire. Also available on the round diagnostic connector at the back of the engine compartment (black wire, Pin #1)

RaceCapture/Pro Timer RPM Configuration

• Timer Mode: RPM
• Timer Speed: Medium
• Pulse Per Revolution: 3

Engine Temperature

In research

Fuel Level

In research

• Forum discussion

(Needs verification)

• 0 ohms empty
• ?? ohms 1/4
• ?? ohms 1/2
• ?? ohms 3/4
• 260 ohms full

Oil Pressure

Recommend a dedicated 10 bar / 145 PSI 0.5-4.5v pressure sensor. Pressure Sensor

Road speed (differential speed sensor based)

This calculates gear and speed based on the differential speed sensor. Assumes engine RPM is connected to the first RPM input.

The differential speed signal is on a black w/ white stripe wire and can be found in the following location:

• Pin 2 on connector X17 to the back of the gauge cluster
• Pin 10 on connector X22 on the cruise control module behind the glove box
• Pin 10 on radio connector

setTickRate(10) --10Hz 

--virtual channels 
--addChannel("name",SR,prec,min,max,"unit") 
speeddiff_id = addChannel("Speed_",10,0,0,160,"MPH") 
gear_id = addChannel("Gear_",5,0,0,5,"gear") 


--global constants 
--edit these to match your car
first = 4.20 
second = 2.49 
third = 1.66 
fourth = 1.24 
fifth = 1.00 
final = 3.46 
tirediameter = 24.7 

--global variables 
rpm = 0 
rpm_diff = 0 
speed = 0 

function updateSpeedDiff() 
   rpm_diff = getTimerRpm(1) 
   speed = rpm_diff*tirediameter*0.002975 
   speed = speed + 0.5 -- round because 0 prec. truncates 
   setChannel(speeddiff_id, speed) 
end 

function updateGear() 
   rpm = getTimerRpm(0) 
   local gearErr = 0.15 
   local gear = 0 
    
   if speed > 2 then 
      ratio = rpm/(rpm_diff*final) 
      if ((first  - ratio)^2) < (gearErr^2) then gear = 1 end 
      if ((second - ratio)^2) < (gearErr^2) then gear = 2 end 
      if ((third  - ratio)^2) < (gearErr^2) then gear = 3 end 
      if ((fourth - ratio)^2) < (gearErr^2) then gear = 4 end 
      if ((fifth  - ratio)^2) < (gearErr^2) then gear = 5 end 
   end 
     setChannel(gear_id, gear) 
end 

function onTick() 
  updateSpeedDiff() 
  updateGear() 
end

External Reference

• BMW E36 Wiring Diagram
• Wiring Troubleshooting Manual