P0446 Code and Remote Start 2017 Sierra

4weight · January 7, 2019

Roger that.

JimCost2014 · January 8, 2019

3 hours ago, 4weight said:

Interesting you say that. Asked him about battery life span and he told me it’s all over the board. Some go 100K some are dead off the transport truck. I’ve always been an Interstate guy what are your thoughts.

Honestly, I like to keep them as factory as possible, have had good luck with the AC Delco replacement batteries. There is a new post, a guy is trying to remove the EVAP Solenoid, because he is throwing similar codes to yours,the wires were hit by something. Wonder if this related to your problem?

4weight · January 8, 2019

58 minutes ago, JimCost2014 said:

Honestly, I like to keep them as factory as possible, have had good luck with the AC Delco replacement batteries. There is a new post, a guy is trying to remove the EVAP Solenoid, because he is throwing similar codes to yours,the wires were hit by something. Wonder if this related to your problem?

I’ve been in mud and dirt hunting since I bought this truck. We’ve had so much rain here in Texas. My gut is some some mud or something may have impacted the system.

JimCost2014 · January 12, 2019

On ‎1‎/‎7‎/‎2019 at 6:47 PM, 4weight said:

I’ve been in mud and dirt hunting since I bought this truck. We’ve had so much rain here in Texas. My gut is some some mud or something may have impacted the system.

So, what have you been able to find out?

JimCost2014 · January 12, 2019

On 1/7/2019 at 6:47 PM, 4weight said:

I’ve been in mud and dirt hunting since I bought this truck. We’ve had so much rain here in Texas. My gut is some some mud or something may have impacted the system.

Found this from another post,

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to be developed in the EVAP system. The engine control module (ECM) commands the EVAP purge solenoid valve Open and the EVAP vent solenoid valve Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the ECM commands the EVAP purge solenoid valve Closed and the EVAP vent solenoid valve Open. The ECM monitors the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 in H2O in a calibrated time, this DTC sets.

4weight · January 12, 2019

Drove it this week about 500 miles on my last deer hunt of the year and no code or check engine light has come back on. Nothing to report yet.

newdude · January 12, 2019

On ‎1‎/‎7‎/‎2019 at 9:47 PM, 4weight said:

I’ve been in mud and dirt hunting since I bought this truck. We’ve had so much rain here in Texas. My gut is some some mud or something may have impacted the system.

Could have had a bit of dirt/mud on or in the vent solenoid filter (mounted along the filler neck). That would cause a restriction in the system and set the P0446 EVAP Vent System Performance code.