Hi anyone come across this before ran vcds on live data lambda stuck on 1 no fluctuations only 1 .I know 1 equals 14.7 atmosphere
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Basically its a theoretical ideal value of air/fuel mixture that the ecu tries to keep to at idle so that emissions are kept low. However the engine needs different values for power and cruise so our vehicles are only controlled around idle.
So when its controlled by the lambda sensor it is called closed loop. When its not its called open loop.
If the reading is not changing after @1.30 minutes and is fixed when the problems start to occur, I think that means you are stuck in open loop. As we have said previously, even though you have changed the sensor it does not mean there is not an issue with either the signal to and from it or the heater circuit! -
Lambda factor 1
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It takes ca 5 minutes to check if your Lambda sensor is ok ( with a scope).Comment
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Lambda factor 1
Left off the car yesterday just thought of a question i called around to the Aston Martin workshop this morning (i know the owner ) he asked have you measured the voltage in 1 of the 2 white wires from the lambda probe , it should show volts , i went back to the car ignition on engine not running and got no volts at all ,is that correct or incorrect , pleaseComment
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As explained previously, the single wire (signal) will have a tiny amount of voltage of 0.45-0.5V from the ecu with ign on.
The heater circuit the other 2 wires, one will only have voltage when the engine is running becuase the power is fed from the fuel pump relay to the fuse concerned.
Being amateurs and not having scopes etc, we can be reasonably scientific by watching the Lambda control via VCDS. If it doesen't change after 1-2 mins then there is an issue. If it starts to fluctuate then we can assume it functions.
Basically the lambda needs heat to function and thats why it is heated electrically so as to get it up to temperature as quickly as possible rather than just rely on the heat from the exhaust.Comment
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