P0443 is a very common OBD2 code. It’s generic, which means that it has the same meaning for the Chevy Express as it would for any other vehicle. If your Express has this code, it is indicating the EVAP purge control valve circuit is malfunctioning.. This is typically caused by a short in the wiring to or from the purge valve solenoid, or an issue with the solenoid itself.
Before you do anything, make sure the gas cap is on and sealed tightly. A bad gas cap can throw this code. It’ll usually be accompanied by other codes as well, such P0455.
Your vehicle’s Evaporative Emissions Control System is responsible for sending fuel vapor from the gas tank and sending it to the intake, where it can be burned. Otherwise these vapors are sent out into the air.
P0443 Quick Facts
- P0443 indicates that there is a problem with the wiring to/from the purge valve or the purge valve solenoid has a short/open circuit.
- It typically won’t affect the way that your Express runs.
- You may smell gas.
- Most commonly caused by a bad purge valve solenoid.
- Checking the gas cap can save a lot of time.
P0443 Symptoms: Chevy Express
There typically won’t be much in the way of noticeable symptoms associated with P0443 and your Express. Here are the most common ones:
- Check Engine Light– This is often the only symptom that you’ll see with this code.
- Gas Smell– If the purge valve is stuck shut, when the fuel vapor builds up it will escape into the air. You may smell gas when you aren’t moving very fast.
- Lean Condition– A lean condition indicates that the ignition process is occurring with too much air and not enough fuel in the mixture. If it’s bad enough, it can cause the engine to run rough. This is not very common though. You may see P0171 or P0174 with this code if that’s the case.
Express P0443 Causes
P0443 indicates that there is a problem with the process that commands the purge valve solenoid. The Express’s ECM commands the purge valve by activating a ground circuit. P0443 occurs when the ECM has told the purge valve to open and it detects that didn’t open due to a wiring issue.
- Purge Valve Solenoid– The wiring in the purge valve solenoid can go bad, which means it can’t respond to instructions from the ECM.
- Wiring Issues– If the wiring harness from the PCM to the purge valve solenoid is frayed or shorted out, the purge valve won’t open and P0443 will be thrown. Take a look at the wiring harness plugged into the purge valve solenoid and see if it looks undamaged and that it is secure.
How to Find a Short in a Car (Backyard Mechanic)
P0443 Diagnosis: Chevy Express
A good code scanner can really help aid you in diagnosing P0443. You’ll be able to command the purge valve to open. When it opens, you should be able to hear it. If you don’t hear anything at all, you’ll need to check to see if the purge valve solenoid is getting any voltage. If it is, and the ground is good, it’s almost certainly the solenoid that is at fault.
If there isn’t voltage at the solenoid, you’ll need to go back and see if there is a wiring issue. You’re going to be looking for frayed and shorted wiring going to the solenoid.
Here’s a good YouTube video on how to diagnose P0443:
P0443 is a relatively easy trouble code to diagnose. If there is anything you would like to add below, please leave a comment. Good luck fixing your Chevy Express!