Check engine light

Maintenance/Repairs
1

check engine light comes on, on my 2004 dodge ram 1500,hemi, when a super hot day follows a very cool night here in denver. taking it to the dealer twice found nothing wrong except it cost me $100 each time to shut the light off. I then found when i go to the mountains above 8500 ft or down to sea level, the light goes off by it self, saving me the $100. Their are no service bulletins about this problem, so I must be the only person with the problem of a truck crying wolf with the light.

2

by the way, the light comes on when I start the truck around 5pm of the above mentioned day.

3

Go to your local Advance Auto Parts when the check engine light is on - they’ll read the code for free. Get the actual code (it will be in the form of P0123) and post it back here.

4 
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.  I suggest you stop seeing the dealer unless your car is still under warranty.  Dealers are no better (or worse) than independent mechanics, but they are almost always more expensive.

Regarding warning lights:

  1. if the coolant temp light comes on, shut off the engine ASAP

  2. if the oil warning light comes on, shut off the engine ASAP

  3. if a FLASHING MIL/CEL comes on, shut off the engine ASAP

    ASAP means driving to the berm of the highway right now and not waiting for the next exit.

But if the MIL/CEL is not flashing, then it’s not an urgent indicator.

5

Save some cash and dealer trips, buy your own tool.

An OBD 2 pocket scanner will plug in under your dash and will let you read codes and shut off the light. The guys at Advance Auto or what ever Big Discount Auto Retailer near you can advise you. Prices start at about $60. It won’t do everything the big ones do, but reads codes, turns out light, nice to have.

6

“Dr. Hath to the ER!”

Hello, Doctor Hath, are you still with us?