The check engine light on for my 2005 Chevrolet Avalanche

My truck has gone around 120,000 miles and the dashboard shows the check engine light illuminated. I had the gas cap reinstalled as it was loose. Also, I had oil level checked and it is fine. The operating temeprature is also okay. There are no issues with the oil pressure either. However, the check engine light is still on. What should I do?
Experienced mechanics share their insights in answering this question :
Hey there, thanks for writing in about your 2005 Chevrolet Avalanche. If the gas cap was loose but then later taken care of, then the light may be due to another issue. You will need to have the Check Engine Light scanned for codes and cleared of codes. The gas cap code will not clear on its own without clearing it. If you need to have this taken care of for you, a local expert from YourMechanic can come to your car’s location to diagnose the Check Engine Light and resolve this issue.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Start the car, let it run for one second, and then turn it off. Let the engine sit quietly for two to three seconds, and then repeat the whole process two more times. If this doesn`t work, it`s not necessarily proof that there`s a deeper problem at play.
Low oil pressure

Low oil pressure is a common cause of a check engine light turning on, and it can seriously interfere with your car`s performance. Usually, if this is the case, your oil light will also appear.

Low Oil and Check Engine Light

However, low oil pressure, which can be caused by low oil levels, can be a reason for the check engine light to turn on. Low oil pressure can seriously interfere with your car`s performance and disable your vehicle if not addressed immediately.

Check Engine Light comes on

If the oil level sensor is working correctly, it will trigger the oil light to come on your car, truck or SUV when the oil level is low. It`s also common for it to trigger the check engine light if the sensor is damaged or faulty in any way.

In most cases, successfully repairing the issue that caused your light to come on will cause the check engine light to turn off automatically—but only after 10 to 20 “cycles”. A cycle, in this instance, refers to the process of turning the vehicle on, running it for some time, and turning it off again.
Manufacturers used to recommend that you check your oil when the engine was cold, to give the oil a chance to settle in the oil pan. As CarTalk notes, however, many manufacturers have since recalibrated their dipsticks to read correctly even when the engine is warm.
With most cars, it`s recommended that drivers check their oil when the engine is cold. However, some automakers recommend checking when the engine is warm for certain vehicles. To determine for sure which one applies to your car, check your Owner`s Manual.
If the oil level and condition are okay, the engine is running normally, but the oil light is still on, the likely culprit is a worn-out oil pressure sensor. In this case, you can safely drive, but you will want to get the car checked out and the sensor replaced by a qualified mechanic as soon as possible.
Dirty Oil Filter

Just before the oil filter clogs enough to bypass the filter media, the oil flow out of the oil filter will be reduced and can reduce engine oil pressure. To avoid low engine oil pressure, make sure your oil filter is changed with each oil change.

Sometimes, the check engine light comes on to let you know that there`s a problem with the car`s internal diagnostic mechanism. That means the system could be “finding” a problem that doesn`t exist, or it could be that loose wire systems are creating a false positive in the system.
Press the odometer`s Trip and Reset buttons while turning the ignition key ON. After turning the key ON, release the odometer Reset and Trip buttons to check if the Diagnostic Trouble Code or DTC appears on the odometer display.
3) Disconnect the Battery then Reconnect

Ideally, this will clear the data, turning off the light. You can then reconnect the battery and turn the ignition on. After about a minute, the check engine light code should be off.

Symptoms of a faulty oil temperature sensor:

Check engine light on: In some cars, a faulty oil temperature sensor can lead to the check engine light turning on. Oil gauge not moving: Faulty wiring can lead to a severed connecting between the sensor and gauge. This can prevent the gauge from showing any reading at all.

Bad Gas, What are the Symptoms? If you`ve inspected the gas cap, the problems you are having may be due to contaminated fuel. If a car, truck, or SUV has trouble starting, will not accelerate, or just is not running smoothly, then it`s possible you just have a contaminated tank of gas.
To make sure the check engine light does not reappear, it`s recommended that you drive your car 30 to 100 miles. This enables the vehicle`s “Drive Cycle” to reset, as the various sensors need time to recalibrate.
Ideal Engine Temperature for an Oil Check

This means the engine should be typically between 230-260 degrees Fahrenheit when you check it. At this temperature, the oil will be thin enough to accurately measure the oil level and viscosity.

Blue smoke from the exhaust: Bluish smoke can indicate your car is burning oil during the combustion cycle. Burning oil smell: A thick burning oil smell could mean oil is seeping onto hot engine parts. Frequent low oil light warnings: Regular low oil warnings can indicate excessive oil consumption or a car burning oil.
When the oil light on your dashboard comes on, it might mean your vehicle has low oil pressure. This drop in oil pressure could be a sign of a few things: you are low on oil, your oil is dirty, or you have an oil leak.
Once you have your oil, make sure your car is again parked on level ground. Your engine should be cool, and you should wait at least 20 minutes to give the oil time to drain fully back into the sump. 4.
Colder temperatures can actually increase oil pressure, but the churning oil in the engine may create air bubbles. Thicker oil may hold onto those air bubbles longer, making the oil pressure gauge read a lower value.
Low pressure means there either isn`t enough oil in the system or the oil pump isn`t circulating enough oil to keep the critical bearing and friction surfaces lubricated. If the light comes on while at speed, do your best to pull off the road quickly, turn the engine off, and investigate the problem to avoid damage.
When your engine oil is running low, it stops lubricating the engine components. When these parts are no longer well-oiled, they cause loud clunking, knocking, and grinding sounds. This can cause your rods to break, which will give off the knocking sound from underneath the hood of your vehicle.
Oil Level Is Too Low

The oil level dropping below the minimum dipstick line is one of the most common causes of low oil pressure. This can happen at any time, even if you`ve recently had an oil change. Over time, engines burn oil more quickly. This is due to piston rings wearing, seals leaking, and so on.

Oil-filter problem

An oil filter obstruction or blockage can also cause oil pressure to suffer. Oil filters include pressure relief valves. If this valve is damaged, oil will easily pass right through, reducing pressure. It may go without saying, but it is important to also change the oil filter with each oil change.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Check engine light refuses to go off after engine replaced
ANSWER : Hello there, you have a long series of issues going on with your 2013 Hyundai Sonata. If you keep getting a repeating oil light on than there is likely a fault in that system.

Since this fault has lasted after the engine was replaced it could be a oil pressure sensor, wiring harness fault, ECU fault, oil pump, oil strainer clogged, or low oil pressure.

To diagnose this issue properly you need a complete vehicle inspection to start from square one and identify the root cause of all this.

While driving on freeway truck goes into a limp mode, and the check engine light, abs light, parking break light, service brake
ANSWER : It is possible that you could be having an issue with your powertrain control module. This is somewhat of a common problem on many GM vehicles. I would recommend having your vehicle inspected by the dealership to determine if the powertrain control module is functioning properly. If not, a reflash of the powertrain control module may resolve the issue but often times it must be replaced.

Car started to slow down and then the check engine light, battery, and engine oil light came on. What could cause this?
ANSWER : Hi there. It is possible that the battery cable came loose or the wires to the oil pressure sensor has came loose or failed. Check the battery cables and make sure that the terminals are tight and clean. Check the wires to the oil pressure sensor and make sure that they are connected and not broken. If everything looks good, then the oil pressure sensor may have failed. Plus, check the computer for codes and see what is stored. This will lead you to the part that could have failed. I recommend replacing the oil pressure sensor then checking to see if the lights will go out. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, that can assist you with the warning lights that came on.

2006 Ford Mustang has check engine light on
ANSWER : There are countless potential causes for your illuminated check engine light. The mechanic manually turned off the light, but it came back on because the problem has not been fixed. The first place to start is retrieval of the stored diagnostic trouble codes (DTCs). These codes serve as a starting point for any further diagnostics a mechanic may perform. Codes will be stored anytime the check engine light is on. Since the first mechanic was unable to fix your concern, I recommend giving the professionals at YourMechanic a call. We offer expert check engine light diagnosis and repair.

p0011 code,check engine light one, changed bank 1 vvt solenoid and check engine light still on?
ANSWER : The P0011 code is typically caused by oil issues with the car. I would particularly make sure the engine oil level is not low. The VVT solenoid relies on proper oil levels to do their job. If they don’t have enough oil, they won’t work. You can have a mobile technician from YourMechanic visit your home or office to inspect the Check Engine Light for you. If you follow through with a repair with us you will be reimbursed for the cost of inspection.

Traction light/reduced engine power and check engine light coming on
ANSWER : Hello. From what you describe, it would appear that your vehicle may be experiencing some sort of intermittent wiring or sensor issue. If the problem occurred again after driving over a bump, then it may be possible that a damaged or loose wire is shorting or having contact issues. A common issue that can cause stalling is a faulty crank position sensor or wiring. I would carefully examine the engine for any loose or damaged wires. If the Check Engine Light comes back on, I would recommend having the trouble codes scanned before resetting the computer.

Check Engine Light comes on after starting pickup
ANSWER : Hello there, thank you for asking about your 1992 Isuzu Pickup. A professional will have the correct equipment to read OBD1 codes. Retrieving the diagnostic trouble code(s) is the first place to start when diagnosing your vehicle. Increasing RPMs changes engine load, which can in turn affect many different sensors and components, causing the Check Engine Light to illuminate. The only way to narrow down the options and find the culprit is through in person diagnosis with an OEM compatible scan tool. A certified technician from YourMechanic can retrieve the OBD codes at your home or office.

The check engine light on for my 2005 Chevrolet Avalanche
ANSWER : Hey there, thanks for writing in about your 2005 Chevrolet Avalanche. If the gas cap was loose but then later taken care of, then the light may be due to another issue. You will need to have the Check Engine Light scanned for codes and cleared of codes. The gas cap code will not clear on its own without clearing it. If you need to have this taken care of for you, a local expert from YourMechanic can come to your car’s location to diagnose the Check Engine Light and resolve this issue.