Trouble Code 443

[Rwayne]

Anyone?

 

[AnonEMouse]

I've been having this same problem and it's driving me nuts! P0443 & P0449 were setting and I got the TIGHTEN GAS CAP warning and MIL was illuminated. Replaced the gas cap....That wasn't it. Checked and replaced the EVAP cannister vent solenoid (it was bad) next. P0443 stopped happening but P0443 wouldn't go away. Next replaced the EVAP purge solenoid valve (TWICE!!!)....Still, P0443 won't stop setting and MIL is on. The computer is indeed actuating the vent solenoid and the solenoid is working. Even still, the computer/ECM must not be sensing that it is working and/or there is a faulty MIL.

So, what could it be of there is nothing actually wrong (all the valves/solenoids working, no vacuum leaks, cannister is fine), yet it keeps setting P0443 and the MIL???? What constitutes a faulty MIL???

 

[DESSKI]

Been getting this same P0443 code and its been frustrating. I've been told its the wiring that routes to the EVAP solenoid on top of intake manifold but it seems okay. I've yet to try the gas cap but will after a fill up.

 

[SLCHOE]

With the key on engine off, check for 12 volts at the purge solenoid connector pink wire (disconnected).

If good, check resistance across the two pins of the solenoid. Should be 20 to 30 ohms if I recall correctly.

Number one in the pic is the solenoid connector. You need to remove the plastic engine cover to get to it.

For those that care I'll expand a bit:

Whenever you see a code that idicates "circuit" like this one does (P0443 - Evaporative Emission Control System Purge Control Valve Circuit) this means the ECM has detected a bad reading on the circuit meaning it can be an internal sensor fault or wiring issue (and very rarely a driver issue within the ECM itself). So a circuit issue is never going to be a loose or even bad gas cap. Gas cap codes are usually EVAP leak codes using the positions of the purge and solenoid valves against the fuel tank pressure which is also monitored in EVAP systems.

This code indicates the PCM was expecting to see a certain voltage on a wire and it didn't see that voltage. In fact it was out of it's normal operating range of voltages that were within the normally functioning range of voltages (which doesn't happen unless there is an electrical issue). Most 3 wire sensors operate within a .5V to 4.5 volt range normally. An open/broken wire would cause the voltage to reach the PCM at 5.0 volts. A shorted wire would show 0 volts (this can flip flop depending on if the control side is power or ground side switched). This is how the PCM knows there is a circuit issue.

 

[Timdenn180]

I've been having this same problem and it's driving me nuts! P0443 & P0449 were setting and I got the TIGHTEN GAS CAP warning and MIL was illuminated. Replaced the gas cap....That wasn't it. Checked and replaced the EVAP cannister vent solenoid (it was bad) next. P0443 stopped happening but P0443 wouldn't go away. Next replaced the EVAP purge solenoid valve (TWICE!!!)....Still, P0443 won't stop setting and MIL is on. The computer is indeed actuating the vent solenoid and the solenoid is working. Even still, the computer/ECM must not be sensing that it is working and/or there is a faulty MIL.

So, what could it be of there is nothing actually wrong (all the valves/solenoids working, no vacuum leaks, cannister is fine), yet it keeps setting P0443 and the MIL???? What constitutes a faulty MIL???

Hey I know it’s been awhile since this post but were you able to figure it out? The p0443 code??? I am having the same issue and have replaced canister,vent valve, and purge valve. Still have the code and help would be greatly appreciated

 

[MassHoe04]

P0443 is specific to the purge valve and indicates a problem with the circuit.

Inspect wires and the connector to make sure they are not broken or damaged.

Since you replaced the purge valve, maybe there is a chance the connector was just not plugged in solid. Pull out the harness connector, spray down with electrical contact cleaner spray and try snapping it back in.

If that doesn't work, maybe damaged/broken/dirty connector pins or damaged/broken connector or damaged/broken wires. See what you can see. Maybe something visible.

Hopefully, it is just a connector that didn't fully seat when you replace the purge valve.

Let us know what you find. Maybe, maybe not... But photos of what you look at might help if you are still stuck. Sometimes the keen eyes of our electrical experts can spot something that got missed.