Hi, I have a 2006 Hummer H3 with 56K miles. My engine light went on today while driving, however, the engine seems steady, the oil was changed about a month ago (maybe 1000 miles ago or less) and there are no error codes in the display (other than the stupid "Service TMP" message that I've been getting for a year now, because the batter dies on my tire pressure monitor and I refuse to pay $100 to replace it.)

Does anyone know if the engine light is scheduled to come on around 56K miles?

I also check the gas cap. I removed it, and replaced it, but the light came back on when I restarted the engine.

Should I be worried?

Thanks,
Fulano

 

Goto Autozone and get a FREE scan.. or just buy an OBDII (aka: OBD2) scanner (they are selling for around $20.00) Post the code when you get it... Probably a PO300

 

What Hummerz said. nobody is gonna know what it means until you have someone with a code reader scan it. I have had an intermittent engine light come on because of my thermostat. P0128. Any other symptoms to report? if not go to an auto parts chain store and ask if they can scan it for you. from my experience with an 06, nothing good comes after 50k and yet i still love this thing. good luck, hopefully its nothing. I am taking mine in tomorrow and will probably be reporting back with a horror story. Yay! its only money. @#$% GM

 

Scan it. If they won't/can't clear the code at that time, you can clear the light yourself by unhooking the battery for a bit.

Keep in mind a solid engine light is nothing emminently dangerous. A flashing light is.

 

Thank you to all. I will get it scanned. Lets see what it really is before I panic.

Aaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhhhh!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks again,
Fulano

 

i have the same problem with mine engine was running smoth but check engine came on some noise coming from under the car like exhaust pipe noise i went under the car and hit the catalytic converter with my hand kind shake it and thats where the sound came from the part inside the catalytic was loose inside and give me a check engine to fix mi problem i fabricate straight pipe with v band flange so u can take that apart really easy run bigger pipe case factory pipes really small. u have a sensor by the catalytic all u have to do is weld a bung an put 3 sparplug spacers so dont get any codes . shake the catalytic maybe thats your problem. good luck

 

You probably want to keep the o2 sensors working properly,they help the computer keep the motor running properly,air fuel ratio etc.

 

OK...the Jury is in...I got myself a OBDII code reader (cost about $90) and check for the error code. I got a P0128 code, which translates to a faulty ECT sensor or a bad thermostat. I'll look at it this weekend, but I think that with 56K miles the thermostat should be about at the end of its life.

I think the CT sensor is at the rear of the engine towards the passenger side of the firewall, but I'm not sure where the thermostat might be. Its usually in the upper water ally, but I don't know if Hummer put it there on the H3s.

Does anyone have any advice on the P0128 error code?

Fulano

 

Coolant low?????.... check/fill the coolant and clear the codes... My hummy has been puttin out random codes... If the code repeats after clearing, then look into it a little further...

 

Yep, I have had it for a little while now but have been too lazy too fix it. P0128 means the coolant temp is not getting up the the appropriate temperature within a certain amount of miles from startup. It only takes 1 negative reading to trip the light, then it takes numerous good temperature readings until the light will reset itself.
Do you have any engine mods? I figured if the coolant temp wasn't heating up enough in time my engine must be running cool which is better right? Anyway, the thermostat is located on the bottom of the radiator and you need to remove the front drivers side wheel to access it. Can diy for around $65 since you have to drain and refill the coolant as well.