7E8 engine Code in Chevy Vehicles – Diagnosing and Fixing

If you own a Chevy, there is a need to know some basics if you are to enjoy it fully. When your vehicle develops a problem, the manufacturer has made it easy for you and your mechanic because the vehicle gives you error codes. These codes are obtained while using an onboard diagnostic scanner, OBD. Using these error codes, you can properly diagnose the problem affecting your vehicle.

7E8 code highlights

• Level of urgency:Medium
• Possible culprits:Anykind ofproblems with engine management system
• Price for repair:$50 - $500
• If neglected:Engine limp mode, electrical issues, problems escalating
• DIY repairs:Possible but complicated
• Can you drive?Carefully

What does the 7E8 error code mean?

The OBD II scanner reads the 7E8 error code when the vehicle has an engine control problem. This error code is not considered dangerous and does not call for an emergency intervention. You can continue driving your car, but it is important to have the cause of this error code sorted out as soon as possible.

The 7E8 error code will appear when the air or the fuel pressure found in the evaporative emission control system gets compromised. This then means that the air or the fuel intake could be compromised. The 7E8 is a generic code, and the OBD II scanner will help you identify the actual problem.

As a generic error code, the 7E8 code can pop up because of a faulty sensor, leading to incorrect reasoning or logic on the part of the OBD II. It is worth noting that 7E8, which indicates an engine powertrain problem, differs from the 7E9 error code. The 7E9 code is for the transmission powertrain.

Symptoms associated with 7E8 code

Several engine powertrain issues will make the OBD II scanner give you the 7E8 error code. For a keen driver, here are some symptoms you will note when a vehicle provides a 7E8 error code.

• Check engine light - Remember that the 7E8 code is related to the engine powertrain. The check engine light will light up on the dashboard when the engine has an issue. The 7E8 code will be stored whenever the engine has a problem, and the CEL will illuminate.
• Poor engine performance - Your vehicle will have a hard time going uphill, especially when under load. This happens because the air-fuel ratio in the combustion chambers can be overly rich or too lean.
• Poor fuel efficiency - Because the air-fuel ratio is off, the vehicle's fuel efficiency deteriorates. You will visit the gas station more often than you are used to.
• Darker exhaust smoke - This issue is related to the air-fuel ratio too. When insufficient air is injected into the combustion chamber, more fuel is injected, which means the fuel is not wholly burnt. Unburnt or inefficiently burnt fuel means darker than usual exhaust smoke.
• Revving sound when the vehicle is at idle - Chevy owners whose vehicles have given the OBD II a 7E8 code report of hearing their vehicles revving while still in idling mode. Unfamiliar engine sound or noise could also be a symptom of a 7E8 issue.

What causes the 7E8 code?

As stated above, the 7E8 engine error code is generic, which can be caused by a single factor or combination of them.

• Damaged fuel vapor lines

When the vapor lines are damaged, excess fuel is returned to the fuel tank for recirculation. The vapor lines could also leak or be unplugged, making the fuel system's vapor and fuel balance unstable. Such leaks lead to poor fuel economy, and the OBD II scanner will give you code 7E8.

• Damaged fuel tank cap

A fuel tank cap keeps the fuel and fuel gases from exiting the tank. The fuel cap is equipped with a valve which helps control the fuel pressure inside the tank. It also prevents debris and water from entering the fuel tank. The cap helps keep the fuel smell from entering the vehicle's cabin. A faulty fuel tank cap or an imperfectly tightened one leaks fumes into the cabin. Such a cap causes poor fuel economy and triggers error code 7E8.

• Damaged fuel tank pressure sensor

The fuel tank pressure sensor, or the FTPS, is a part of the vehicle's evaporative emission system and is responsible for monitoring the fuel pressure. The sensor will detect a broken fuel tank cap and send an error message to the control module, giving a 7E8 error code.

• Damaged canister close valve

The fuel system of your vehicle releases fuel vapour into the atmosphere. The canister close valve, which is filled with charcoal, ensures that such vapour being released into the atmosphere is clean. This is a government requirement as a properly working canister close valve helps reduce air pollution and, by extension, global warming. If the canister is broken, it will cause fuel gases to be released into the atmosphere. The vehicle control will be alerted, and the 7E8 error will be recorded. 

• Damaged purge control solenoid valve

This is the valve responsible for controlling or regulating the emissions from your vehicle. The valve captures the fuel gases in the charcoal canister and returns such into the fuel system.

• A broken fuel seal

A broken fuel seal will also set off the 7E8 error code. The fuel seal will prevent oil leaks on the cam case. When the pump is broken and leaks, the engine will run out of oomph and a 7E8 error code will be recorded.

How do you fix the 7E8 error code?

The 7E8 error code, as stated earlier, is generic and can come up for several reasons. To fix this code then means that you must also evaluate the other symptoms that show alongside it. The solution could therefore be a cheap one to fix or an expensive one. It could also be easy to solve or laborious. Here are the suggested ways to fix this issue;

• Repair the fuel filler pipe if it is broken. If severely damaged, consider replacing it.
• The faulty canister close valve should be replaced. At the same time, check whether the purge control solenoid valve is damaged. It can be repaired or replaced.
• Where the fuel pump seals are broken, replace them.
• For the leaking or disconnected vapor lines, repair or replace them depending on the severity of the damage.
• If the fuel tank cap is faulty, confirm whether it is just a case of improper tightening, or the cap is broken. You will need to replace the cap if it is damaged or missing.
• Replace the tank pressure sensor if faulty.

Diagnosing the 7E8 code

The 7E8 error code is definitely not a code many people like because of the many variables that go with it. The many possible causes of the error mean diagnosing the error can be time-consuming. It is then advisable that you visit a garage if you don't have an OBD II scanner or are not an experienced driver.

Diagnosing the 7E8 error code requires you to start by visual inspection to locate any possible leaks. You should then enter the cabin and observe for any gasoline scents in the cabin. You should also listen to how the vehicle idles. You will likely hear the vehicle revving for Chevy vehicles when in parking mode.

The OBD II scanner is the most effective method of diagnosing the 7E8 code. You should be able to fix the problem if you have the proper diagnostic machine. You should quickly diagnose the error if you are a keen observer of how the vehicle consumes fuel or if you smell fuel inside the cabin.

How costly is it to fix the 7E8 code?

When fixing the 7E8 error code root cause, you should know that the cost varies significantly depending on the Chevy model and the item requiring replacement or repair. The cost also differs drastically based on location and labor charges. In many instances, however, the cost ranges between $500 and 700 dollars.

Conclusion

The 7E8 error code in the Chevrolet vehicles is related to the 7E9 code, but they are very different. While the 7E8 addresses the engine powertrain, the 7E9 code is for the transmission powertrain. The 7E8 code is not severe and will allow you to drive around. However, you should make an effort to resolve the issue at the soonest possible opportunity to avoid the deterioration of the situation.

The Chevrolet vehicles will also record a 7EA error code. This is not an error code but an information source. The code can appear alongside 7E8 and will tell you which component group to look into. The code may also mean an error in reading the codes, and all you will require is to clear the check engine light error.