IAT sensor reads 68f constantly even unplugged

[rsdoherty88]

Trying to determine if ecu will default to 68f if the circuit is not complete.  I noticed while trying to tune my car that the ecu never moves away from 68f even when temps are clearly much higher.

 

Any ideas what would cause this?

 

The ecu has been on the car and was working before I rebuilt the engine. The previous motor overheated, bot sure if that could have cause sensor to go haywire or maybe even wiring? New motor has bigger cams and intake plenum, so I've been learning how to tune and make adjustments myself.

[Richard Hill]

Are there any fault codes logged for that sensor? If its at 0V or 5V the error value will be substituted.  

Also, check your error low and error high values.  Normally these should be 0.05 and 4.95V 

 

HTH, 

Richard 

 

[rsdoherty88]

I will check when I get home. I don't think I noticed any fault codes, but maybe I wasn't looking in the right place.

Regarding error value, is that something that is customizable? 

Also, if my memory serves me I believe the sensor low and high values were set to 0v and 5v.

[Richard Hill]

Yes, error values are adjustable. 68F is 20 Degrees Celsius so its possible that's the error value.

 

 

 

The event log will tell you if you have any errors logged.

 

 

[rsdoherty88]

After looking through analog inputs I found I had maf intake temp, but it was not showing up as inlet air temp. So I went and edited its function to inlet air temperature and now IAT reads the correct temperature so it can be used for ecu adjustments to mapping. In case this happens to someone else, now u know