SureTrack Real Fix: Mirror Mirror

Real Fixes from Mitchell 1’s SureTrack® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is available at no additional cost in our ProDemand product.

Chasing your tail around trying to solve a problem with a sensor that doesn’t exist can be very frustrating, especially when you find out why it’s not there. SureTrack community member ProAutoValdosta had a Ford F250 Super Duty truck that had a code for a bad reading on the ambient air temperature sensor but they couldn’t even find the sensor. They posed the question to the community, and with the help of fellow community member Ericsautomotive and others, they were able to resolve the issue quickly.

The following Community Fix summarizes the interaction between members of the community that led to the solution.

2015 Ford F-250 Super Duty XL 6.2L

Code P0073, missing sensor.

Customer states that check engine light is on. Outside temperature display incorrect.

Diagnostic Steps Performed/Parts Replaced
Truck came in with Check Engine light on and code P0073 – Ambient Air Temperature Sensor Circuit High. The readout on the dash says -40 degrees when the actual ambient temperature is in the 80’s. Live data says ambient air temp voltage 5.0V and ambient air temp sensor fault. Where is the sensor? The service manual says it’s in the right mirror. It is NOT in the mirror. I found info stating that if it is a fleet or work truck package (which this one is), it will NOT be mounted in the mirror, it’s mounted near the radiator, behind the bumper, on the side of one of the headlights, or it doesn’t have one at all. If the truck doesn’t have one, apparently the PCM extrapolates the ambient temperature based on the intake air temp sensor and the engine coolant temp sensor…however both of those sensors are working normally on this truck. And if it doesn’t actually have an ambient temp sensor, why does the scan tool show “fault” and a voltage readout? If it does have an ambient air temp sensor, where is it?

Best Answer from Community Member Ericsautomotive
If the sensor is not in either location, is the PCM programmed correctly? I’ve seen that before.

It turns out that the owner swapped these mirrors with an older truck…the ambient air temp sensor WAS in the original right side mirror, but since the older model mirrors didn’t have a spot for the sensor, the owner simply left the sensor out and tucked the wiring harness behind the door panel. That info would’ve saved me quite a bit of time!

Replaced mirror with correct one that has sensor. Cleared code and it did not return. Temperature reading now correct.

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.