EGR monitor, IAT and coolant temperature sensor...

[Omahaug]

I hooked up my scan tool to a car that won't set the EGR monitor for some reason.

I left the car overnight and the following morning on a 60-70F day (sun hasn't come up yet) the ECT is registering at 33C. That's about ~91F. Shouldn't the ECT register the coolant much lower than ambient air temperature? The IAT was the same. After driving the car up to operating temperature each are around 80C.

I wonder if these sensors are misbehaving and I wonder if has to be below a certain threshold for it to consider it a new drive cycle.

Anyone have any idea what common things cause the EGR monitor to not set on a Nissan?

 

[Lubener]

80 degrees C is 176 F and that seems low for the ECT at operating temperature.. ECT is sending the wrong info or your thermostat is hanging open. It should be around 195-210+. IAT should be close to ambient air temperature after sitting overnight. I wouldn't expect it to be anywhere near the coolant temp (when at operating temp)but the incoming intake air plus heat from engine side. If anything, after sitting overnight, I would expect the ECT to be at or slightly higher than the ambient air temperature.Maybe the engine was not completely cooled down.Overnight, the coolant temperature can't be lower that the ambient air temperature.