C20XE NOT showing fault code

[hendrix]

Any ideas why, now my lambda sensor is completely mullered (read not connected) that the ecu light on the dash isn't lit??
When I turn the key the light comes on then after I start the engine (running fine) it doesn't stay on.

[Spudly]

Possibly a non lambda ecu/loom so its not thinking anything is wrong?

Arent ya sposed to be posting up complaining when the ecu light is on and its not running right, not when its fine and not on god youre never happy you andy haha!

[hendrix]

I know I know!!! Just wondered why it wasn't bitching at me.
When I got it the exhaust manifold had a lambda sensor with no wires attached so swapped it for my spare. But also changed the ECU to the spare motronic 2.5 which is the one for Dizzy XE with lambda.
Confused

[novarobbo]

you wired it up

[Adam]

The same management is used on both lambda and non lambda engines. Just the ecu code (GQ etc) is different.

Have you let the engine get fully warm?
The ecu ignores the lambda until the coolant is warm

[Spudly]

Oh it wont have been fully up to running temp i doubt so that could be why then adam

[novarobbo]

its never even been running with water in it afaik so it wont of been at any kind of running temp

[hendrix]

yep still no coolant hence running it for about 4 seconds max.
although it will have coolant in by tonight

Thats what I thought Adam, something to do with open and closed loop?

[Rich]

Once the engine gets up to its normal running temp the o2 sensor circuit goes into closed loop and starts working. Until then, its just on a preset setting to keep it running.