Skip the auto shop - Our mechanics make house calls

Q: Why does the check engine light keep coming back on?

asked by on

I have 97,000 miles on my 2006 GMC Sierra, and recently I have had to get the Check Engine light reset more than once. It first came on when some sensor went bad, but when it came back on not too long later, the mechanic looked at it and didn’t find anything. Is this going to be an ongoing problem? Is it possible that something broke when the sensor was replaced? This is my work truck so I plan on getting some more life out of it yet.

A: The check engine light comes on and stays o...

The check engine light comes on and stays on if the onboard computer sees a problem that could cause an increase in emissions or a problem with its systems. After looking at most of the possible codes or issues that could cause the check engine light to come on. The most common problem your vehicle is having is an evaporative system problem since you say a technician could not find any problems. The fuel tank evaporative system vent solenoid could be the failure because they are prone to getting dirt and debris in the solenoid filter causing them to not vent the tank properly. The valve will operate electrically.

My recommendation would be to have your computer system checked for codes relating to the evaporative fuel tank system by a qualified mechanic. A certified mechanic with YourMechanic can inspect and diagnose the fuel tank system at your home or office. The fix recommendation would be to replace the evaporative vent solenoid and the fuel tank cap.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Iod Fuse / Check Engine Light

Your first order of business is to extract the problem codes which are driving the Check Engine light. Hesitation to start when cranking - if this is what you mean - could be a sign of a weak power supply...

Q: The Aveo starts to kick when i start to accelerate at 2000rpms and its everytime

When you say your car kicks, I think of a misfire in the engine under load. If you are getting a misfire, then a trouble code for the cylinder would be set. You should scan the computer and identify...

Q: Coolant leak - 2002 GMC Envoy

Hello. If the coolant leak is coming from a location near the cooling fan, this may suggest your water pump may be leaking. A common place for this to happen is from the water pump shaft as there is a...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.