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Old 18th June 2013, 00:00
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MadDogMoggy MadDogMoggy is offline
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Default Confused

Ok this has got me thinking!

My assumption was that the ECU fed the O2 sensor with a current/voltage and measurd the voltage drop (ie the variance in the resistance of the sensor, which change with the amount of oxygen in the exhaust gas)

Bearing in mind the following is from my build notes - I've not actually looked at the car this evening.

I wired up the ECU following RichH's wiring diagram, which was invaluable.

The connections that I have are:
E1 Fuel relay coil
E4 O2 Sensor -ve (grey wire)
E7 Main relay coil
E9 Relay for O2 Heater
E26 RPM feed
E31 MIL feed

A1 O2 Heater (now disconnected)
A2 12v feed from main relay
A3 12v feed from main relay
A6 O2 Sensor +ve (black wire)
A18 Speedo
B8 Fan relay

The ECU doesn't appear to have an earth (not via a pin anyway), which is a bit confusing!

I've looked through a PDF of a manual which has some pin outs for the ECU, but I'm not sure if it cover the Type R. Interestingly:
A4 and A5 are listed as grounds for the ECM circuit
A16 is AFS sensor (-ve)

E4 is just listed as 'sensor ground'

Could this mean then that a) my ECU isn't earthed properly, and b) my O2 sensor is wired wrong?

There also seem to be a lot of other connections missing (like those to VTEC solenoid)!

I'm wary of adding/changing wires in case I damage the ECU!
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