Tow Mirrors

mattforney · October 28, 2021

Howdy,

I am looking for a little bit of help. I bought a late 2015 Silverado 2500HD a few months ago. The previous owner put after market tow mirrors on, when I extended the mirrors to tow our trailer it triggered the P0073 AAT CEL.

I've read up on other posts about the 2500 having a sensor in the mirror, which this one does not have. My question is what is just a fluke that it wasn't triggered prior or is there a bypass somehow? Or was there no sensor to begin with?

Thanks for any help you guys can provide.

This is the mirror that was installed.

https://www.americantrucks.com/silverado2500-towing-mirror-twm-020-t888-bk-sm.html?utm_content=AT%20Exterior%20-%20Mirror%7CStore%20Brand&T5_Var4=HS3932#customer_reviews

JimCost2014 · October 29, 2021

3 hours ago, mattforney said:

Howdy,

I am looking for a little bit of help. I bought a late 2015 Silverado 2500HD a few months ago. The previous owner put after market tow mirrors on, when I extended the mirrors to tow our trailer it triggered the P0073 AAT CEL.

I've read up on other posts about the 2500 having a sensor in the mirror, which this one does not have. My question is what is just a fluke that it wasn't triggered prior or is there a bypass somehow? Or was there no sensor to begin with?

Thanks for any help you guys can provide.

This is the mirror that was installed.

https://www.americantrucks.com/silverado2500-towing-mirror-twm-020-t888-bk-sm.html?utm_content=AT Exterior - Mirror|Store Brand&T5_Var4=HS3932#customer_reviews

Welcome to the site.

My guess is the 4th one down, since your new mirrors are not sending any signal/current (kind of like a break) to your truck now.

There are several things that could cause the P0073 trouble code to be stored by the Power Control Module (PCM):

The ambient air temperature sensor has malfunctioned
The wiring has shorted or broken
There is corrosion in the electric circuitry or connector
A break or short in the ambient air temperature harness
Debris that is covering the sensor

Edited October 29, 2021 by JimCost2014

mattforney · October 29, 2021

15 minutes ago, JimCost2014 said:

Welcome to the site.

My guess is the 4th one down, since your new mirrors are not sending any signal/current (kind of like a break) to your truck now.

There are several things that could cause the P0073 trouble code to be stored by the Power Control Module (PCM):

The ambient air temperature sensor has malfunctioned

The wiring has shorted or broken

There is corrosion in the electric circuitry or connector

A break or short in the ambient air temperature harness

Debris that is covering the sensor

I swapped out the air intake a few weeks ago, does the AAT wiring run through that?

I can pull the mirrors off and check the wiring harness in there.

JimCost2014 · October 29, 2021

10 minutes ago, mattforney said:

I swapped out the air intake a few weeks ago, does the AAT wiring run through that?

I can pull the mirrors off and check the wiring harness in there.

I would pull one off, then check the mirrors plug to make sure there are the same number of "pins" as the trucks plug (harness).

If they do not match, makes no difference if you put the sensor back in the mirror.

All powered functions on the mirrors have to get power from the truck somehow. It is a very common problem with the K2 1500's when people swap out standard mirrors to tow style, mainly because the harnesses are not the same.

Edited October 29, 2021 by JimCost2014

mattforney · October 29, 2021

38 minutes ago, JimCost2014 said:

I would pull one off, then check the mirrors plug to make sure there are the same number of "pins" as the trucks plug (harness).

If they do not match, makes no difference if you put the sensor back in the mirror.

All powered functions on the mirrors have to get power from the truck somehow. It is a very common problem with the K2 1500's when people swap out standard mirrors to tow style, mainly because the harnesses are not the same.

Thanks for the info. I’ll take a look tomorrow.