2015 impala issues

[jhwis]

Son's 2015 impala (police model) had occasionally (three or four times the last two months) shut off randomly when at a stop light. There is no stop/start option on this vehicle. He turns key off and it starts right back up and drives fine. It's done it three times in the last two days. Once on a turn now. He did have a code for EVAP stuff but he said the engine light went away a couple weeks ago. Any ideas on this? Crankshaft positioning sensor? Could the EVAP codes have something to do with it? This impala has been a major hassle.

 

[TheBartman47]

Evaporative Emission Control (EVAP) system issues in a 2015 Chevrolet Impala, such as a Check Engine light (often codes P0442 or P0455), are commonly caused by a faulty vapor canister purge valve ($20–$63) or the vapor canister itself. Symptoms include hard starting, rough idle, poor performance, or a strong fuel smell.

 

[jhwis]

Evaporative Emission Control (EVAP) system issues in a 2015 Chevrolet Impala, such as a Check Engine light (often codes P0442 or P0455), are commonly caused by a faulty vapor canister purge valve ($20–$63) or the vapor canister itself. Symptoms include hard starting, rough idle, poor performance, or a strong fuel smell.

yeah...but none of those symptoms. It runs great otherwise.

 

[jhwis]

Upon talking more this morning...He filled up the tank yesterday. I'm thinking indeed it is something with the EVAP canister or purge solenoid. That sorta makes sense. I replaced the gas cap once. I'd like to hear anymore input if anyone has it.

 

[NDIHC]

I've had customers come in with similar complaints. Usually shortly after fuel fill. The evap sysyem often cycles the purge control valve on deceleration, like when coming to a stop sign. If the evap canister is fuel logged and the purge valve opens it will suck in fuel vapors and make the engine stumble or stall. The evap canister can become fuel logged from a leakng fuel cut valve that allows fuel to enter the evap system or by someone squeezing every last drop of fuel they can get into the tank when filling or even just topping off to the next even dollar. Over filling can force fuel past the fuel cut valve. Fuel in the evap system can set codes for almost anything pressure related in the evap system like leak codes or vent/purge solenoid codes because the fuel will affect the fuel tank pressure sensor.
A purge valve sticking open can cause stumble or stall also. If the purge valve sticks open it can be pulling fuel vapors into the intake when it shouldn't. During deceleration the purge valve often cycles open but then closes upon stop. If it sticks open the mixture can get too rich and cause a stall. That will usually set an incorrect purge flow code.

 

[jhwis]

I've had customers come in with similar complaints. Usually shortly after fuel fill. The evap sysyem often cycles the purge control valve on deceleration, like when coming to a stop sign. If the evap canister is fuel logged and the purge valve opens it will suck in fuel vapors and make the engine stumble or stall. The evap canister can become fuel logged from a leakng fuel cut valve that allows fuel to enter the evap system or by someone squeezing every last drop of fuel they can get into the tank when filling or even just topping off to the next even dollar. Over filling can force fuel past the fuel cut valve. Fuel in the evap system can set codes for almost anything pressure related in the evap system like leak codes or vent/purge solenoid codes because the fuel will affect the fuel tank pressure sensor.

Excellent information. What is your remedy for this? I told him to never fill it up and loosen the cap and retighten ONE click the next few times he stops.

 

[NDIHC]

Excellent information. What is your remedy for this? I told him to never fill it up and loosen the cap and retighten ONE click the next few times he stops.

Our procedure when I was at the dealership was to remove the evap canister and weigh it. If it was over weight we would generally replace the canister and fuel cut valve. Some fuel cut valves are not replaceable and the fuel tank has to be replaced if the fuel cut valve isn't sealing. A leaking fuel cut valve is not that common anymore. We used to see it more in the early 2000s.

If it was a case ofsomeone overfilling the tank, of course the remedy is to let the pump shut off and not add any more fuel.

If the fault is with the purge valve we replaced it. You can test a purge valve by disconnecting the electrical connector, remove the hose on the canister side of the purge valve and connect a vacuum gauge. Then start the engine. If the gauge registers vacuum the valve is bad.

Most commonly this condition was caused by either overfilling the tank or a faulty purge valve.

 

[jhwis]

Our procedure when I was at the dealership was to remove the evap canister and weigh it. If it was over weight we would generally replace the canister and fuel cut valve. Some fuel cut valves are not replaceable and the fuel tank has to be replaced if the fuel cut valve isn't sealing. A leaking fuel cut valve is not that common anymore. We used to see it more in the early 2000s.

If it was a case ofsomeone overfilling the tank, of course the remedy is to let the pump shut off and not add any more fuel.

If the fault is with the purge valve we replaced it. You can test a purge valve by disconnecting the electrical connector, remove the hose on the canister side of the purge valve and connect a vacuum gauge. Then start the engine. If the gauge registers vacuum the valve is bad.

Most commonly this condition was caused by either overfilling the tank or a faulty purge valve.

Got it....kid is low on cash, so really what I'm asking is this problem going to get worse if nothing is done or if he doesn't fill the tank all the way will this help? Purge valve wouldn't be bad, but he is two hours away....had a couple of repairs at the local shop and they don't work cheap. EVAP canister will be expensive fix. Not gonna hold you to anything...just want your opinion.

 

[NDIHC]

Got it....kid is low on cash, so really what I'm asking is this problem going to get worse if nothing is done or if he doesn't fill the tank all the way will this help? Purge valve wouldn't be bad, but he is two hours away....had a couple of repairs at the local shop and they don't work cheap. EVAP canister will be expensive fix. Not gonna hold you to anything...just want your opinion.

A fuel logged canister will, in theory, rid itself of fuel eventually through the purge process if no more fuel is introduced to it. So in that case just make sure the tank isn't overfilled. If it is a purge valve I believe the common code would be a p0441 incorrect purge flow if memory serves. A sticking purge valve can be intermittent. Generally if I had an incorrect purge flow code I'd test the purge valve and replace as required. If it was really intermittent sometimes I'd just go ahead and replace the purge valve, especially if the car was still under warranty. If it wasn't under warranty we'd give the customer the option of replacing it or doing further testing to try and catch the valve sticking. Usually the purge valve was cheap enough that it was cheaper to just replace it than to spend hours trying to catch an intermittently sticking valve. So to answer your question, just leaving it as is really isn't going to hurt anything other than a car stalled at a busy intersection could be a hazard. Personally, if it were mine and I knew that I hadn't overfilled the tank, and especially if it had an incorrect purge flow code I'd suspect the purge valve. At that point I'd either test the purge valve or just go ahead and replace it if it was reasonably priced. I have a purge valve to put on my own car. That one has a purge flow code and is hard starting after filling fuel. The valve is stuck open all the time so vapors are pushed through it when filling the tank. I didn't test the valve because it is a little hard to reach and I've seen it happen so many times on my make/model that I'm very confident that the valve is the problem. Plus it only cost something like 30 or 40 bucks.

 

[jhwis]

A fuel logged canister will, in theory, rid itself of fuel eventually through the purge process if no more fuel is introduced to it. So in that case just make sure the tank isn't overfilled. If it is a purge valve I believe the common code would be a p0441 incorrect purge flow if memory serves. A sticking purge valve can be intermittent. Generally if I had an incorrect purge flow code I'd test the purge valve and replace as required. If it was really intermittent sometimes I'd just go ahead and replace the purge valve, especially if the car was still under warranty. If it wasn't under warranty we'd give the customer the option of replacing it or doing further testing to try and catch the valve sticking. Usually the purge valve was cheap enough that it was cheaper to just replace it than to spend hours trying to catch an intermittently sticking valve. So to answer your question, just leaving it as is really isn't going to hurt anything other than a car stalled at a busy intersection could be a hazard. Personally, if it were mine and I knew that I hadn't overfilled the tank, and especially if it had an incorrect purge flow code I'd suspect the purge valve. At that point I'd either test the purge valve or just go ahead and replace it if it was reasonably priced. I have a purge valve to put on my own car. That one has a purge flow code and is hard starting after filling fuel. The valve is stuck open all the time so vapors are pushed through it when filling the tank. I didn't test the valve because it is a little hard to reach and I've seen it happen so many times on my make/model that I'm very confident that the valve is the problem. Plus it only cost something like 30 or 40 bucks.

Big help. Much appreciated!

 

[NDIHC]

Big help. Much appreciated!

It looks like a purge valve for a 2015 Impala is pretty cheap. Must be a common thing. I haven't worked on GM, other than my own Chevy/GMC/Pontiacs/Buick/Olds that I've owned, for over 20 years so I don't know from personal experience. I couldn't find a fuel cut valve listed for it so either GM calls it something else or it is part of the fuel tank. Someone more up to date on GM might have that answer. I worked on an import brand for over 20 years so I'm not real up to date on other brands.

 

[jhwis]

It looks like a purge valve for a 2015 Impala is pretty cheap. Must be a common thing. I haven't worked on GM, other than my own Chevy/GMC/Pontiacs/Buick/Olds that I've owned, for over 20 years so I don't know from personal experience. I couldn't find a fuel cut valve listed for it so either GM calls it something else or it is part of the fuel tank. Someone more up to date on GM might have that answer. I worked on an import brand for over 20 years so I'm not real up to date on other brands.

Again thanks a bunch. I believe the canister is above the fuel tank.

 

[NDIHC]

Again thanks a bunch. I believe the canister is above the fuel tank.

At least the purge valve is under the hood so not too bad to replace!

 

[Sprint 6]

Purge valve stuck open. Only use an OE valve, or you'll induce another problem and chase your tail.

 

[jhwis]

Purge valve stuck open. Only use an OE valve, or you'll induce another problem and chase your tail.

Ok

 

[jhwis]

Purge valve stuck open. Only use an OE valve, or you'll induce another problem and chase your tail.

Thanks I should have said. I appreciate the knowledge.

 

[Hoenes]

Another known issue with this gen of Impala (Though not related to your problem) is the starter relay. Delayed start, or no crank, until a couple of tries later. Sometimes a few minutes. When I replaced it, it looked really burnt on the prongs. Use genuine GM. Parts guy said he sells a lot of them. He also said GM has upgraded them. Just trying to give you a heads up in case it happens to you.

 

[jhwis]

Another known issue with this gen of Impala (Though not related to your problem) is the starter relay. Delayed start, or no crank, until a couple of tries later. Sometimes a few minutes. When I replaced it, it looked really burnt on the prongs. Use genuine GM. Parts guy said he sells a lot of them. He also said GM has upgraded them. Just trying to give you a heads up in case it happens to you.

Good to know. I will remember that.

 

[jhwis]

Purge valve stuck open. Only use an OE valve, or you'll induce another problem and chase your tail.

It appears for now that Sprint 6 and NDIHC were both correct with the purge valve as the culprit. Hopefully, no more issues. Thanks again.