The CEL Just Won't Go Away - P0072 - 2004 XC70

mse · Post by **mse** » 17 Oct 2011, 15:38

I have 2004 XC70 that is showing a CEL. I checked and the code is P0072 - Ambient Air Temperature Sensor Range/Performance. The CEL came on after I replaced the driver's side mirror housing - so I believe the two are connected. The outside air temp seems to be working fine based on the fact it shows on the dash display. I've checked the wiring harness and it seems to be connected correctly.

The only thing that I can think might be causing this code is a faulty temp sensor, which would be odd given the mirror housing and all of the parts are brand new. I thought about trying to replace the sensor with a new one, but cannot figure out how to pull the old one out of the current wiring harness.

Anyone have any thoughts on this? I just want to get rid of the CEL in case something serious does happen that I need to look into. The car is running perfectly fine otherwise.

Post by **JRL** » 17 Oct 2011, 16:29

I think that's one of the many parts that needs to be "initialized" by the dealer.
I'm not 100% sure but if it does (need to be), and you didn't have this done, that in itself would throw the code as it's now not "mated" to the car.
Call your dealer

Post by **jimmy57** » 17 Oct 2011, 17:39

The dash display is the RH mirror and the ECM is wired to one in the LH mirror. Recheck your installation for a backed out wire at the connector on the body side or to see if any of the pins got bent over.

mse · Post by **mse** » 18 Oct 2011, 13:10

Alright. Looks like I've got a couple of things to look into. Thanks for your thoughts on this issue.

proton · Post by **proton** » 19 Oct 2011, 07:23

"The dash display is the RH mirror and the ECM is wired to one in the LH mirror."

do you have the part number for those? can't find it online (2005XC70) I have that code too. My dash is ok but using the Android "Torque" application, I notice that the computer see a different temp that drop slowly to -40! so it is the driver side, right?