Hi all.

I have a 2003 Terios with the MIL light on. The fault is the usual Lambda error but after testing it, I have discovered that there is no feed voltage from the ECU.

In my experience of 4 wire sensors (European cars), two of the wires are for the heater so one wire should have battery voltage and the other an earth, which I do have.

The other two are for the signal, one is a signal earth from the ECU, which checks out ok, and one should be about 450-500mV from the ECU with ignition on and should then fluctuate between 100-900 mV at a fast idle with the engine at operating temperature. This is what I don't have, which indicates a problem with either wiring or the ECU itself. Is this a common issue? And does anybody have a wiring diagram I could use so that I can check the wiring please?

Thank you!