How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jerry Your Own Question
Jerry, Master Mechanic
Category: Buick
Satisfied Customers: 17220
Experience:  ASE Master tech. 30+ years mechanic, shop forman, service manager
Type Your Buick Question Here...
Jerry is online now
A new question is answered every 9 seconds

2004 Buick Lesabre: gas cap..the service engine light came

Resolved Question:

I have a 2004 Buick Lesabre. The check gas cap warning message came on about the same time the service engine light came on and stayed on. The car runs great. Are these two messages related and if so, what do I need to do? I checked the gas cap to make sure it was on correctly, but both messages are still there.
Submitted: 7 years ago.
Category: Buick
Expert:  Jerry replied 7 years ago.

Hello and welcome to Just, Super mechanic here. About your vehicle.


The service engine light will come on when there is a malfunction in the powertrain control system, including any evaporative emmission related problems. The check gas cap is directly related to the engine light being on. The gas cap could be bad, (not sealing) or there could be a leak in the evap system.


The best thing to do would be to have the codes read, (normally autozone and such will do that free of charge) to see which trouble code(s) has caused the both lights to come on.


When we know the code(s) we will have a better idea as to which area the concern may be in, thanks

Jerry and other Buick Specialists are ready to help you