2020 1500 LT 5.3L code P0499.

[DavidBo]

Fresh after the 3 year warranty expired I got my first check engine light; it popped up on the first start of the day, not while driving. The scanner showed a historic fault of P0499, which is one of the ever-popular evap system codes. I did a close visual of the vent and purge solenoids, wiring looked OK and there was nothing obviously wrong, so I'll have to do a deeper dive. I did quite a bit of research and I figured out the basic troubleshooting using a 12VDC battery and a multimeter, but I'd like to know which valve is the usual culprit for this code so I know where to start. I only got the P0499 code, not the more common P0449. Also, I tried clearing the code with my scanner, but the CEL never turned off. I've cleared plenty of codes in the past and the light always went off at least for a little while, but not this time. I'll be pulling the negative battery cable for troubleshooting, I'll see what that does.

Side note: I tried removing the intake plenum from the throttle body, usually a simple procedure but for some reason the bracket on the passenger side above the alternator wouldn't let go. I had the hose disconnected, but even after some healthy pulling it wouldn't come loose. There's no fastener, it's just a pressure fit. Do I need to use more force?

Thanks in advance for any input.

[GMCustomerService]

On 6/7/2023 at 5:08 PM, DavidBo said:

Fresh after the 3 year warranty expired I got my first check engine light; it popped up on the first start of the day, not while driving. The scanner showed a historic fault of P0499, which is one of the ever-popular evap system codes. I did a close visual of the vent and purge solenoids, wiring looked OK and there was nothing obviously wrong, so I'll have to do a deeper dive. I did quite a bit of research and I figured out the basic troubleshooting using a 12VDC battery and a multimeter, but I'd like to know which valve is the usual culprit for this code so I know where to start. I only got the P0499 code, not the more common P0449. Also, I tried clearing the code with my scanner, but the CEL never turned off. I've cleared plenty of codes in the past and the light always went off at least for a little while, but not this time. I'll be pulling the negative battery cable for troubleshooting, I'll see what that does.

Side note: I tried removing the intake plenum from the throttle body, usually a simple procedure but for some reason the bracket on the passenger side above the alternator wouldn't let go. I had the hose disconnected, but even after some healthy pulling it wouldn't come loose. There's no fastener, it's just a pressure fit. Do I need to use more force?

Thanks in advance for any input.

This is certainly not what we like to hear, DavidBo.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2020 Chevrolet Silverado. To do so, please send an email to [email protected] with ATTN: DavidBo/GM Trucks in the subject line.

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[newdude]

On 6/7/2023 at 5:08 PM, DavidBo said:

Fresh after the 3 year warranty expired I got my first check engine light; it popped up on the first start of the day, not while driving. The scanner showed a historic fault of P0499, which is one of the ever-popular evap system codes. I did a close visual of the vent and purge solenoids, wiring looked OK and there was nothing obviously wrong, so I'll have to do a deeper dive. I did quite a bit of research and I figured out the basic troubleshooting using a 12VDC battery and a multimeter, but I'd like to know which valve is the usual culprit for this code so I know where to start. I only got the P0499 code, not the more common P0449. Also, I tried clearing the code with my scanner, but the CEL never turned off. I've cleared plenty of codes in the past and the light always went off at least for a little while, but not this time. I'll be pulling the negative battery cable for troubleshooting, I'll see what that does.

Side note: I tried removing the intake plenum from the throttle body, usually a simple procedure but for some reason the bracket on the passenger side above the alternator wouldn't let go. I had the hose disconnected, but even after some healthy pulling it wouldn't come loose. There's no fastener, it's just a pressure fit. Do I need to use more force?

Thanks in advance for any input.

 

 

DTC P0499 - Evaporative Emission (EVAP) Vent Solenoid Valve Control Circuit High Voltage.

 

Vent valve is probably junk.