I'm on the highway going up hills. Everytime I drive my truck up a hill on the high way the service engine light comes on. Driving on a flat area doesn't make the light come on. So when i finally get to where i'm going and pull over, rev the engine for 10 or 15 seconds the light goes off. What is this telling me or what could be going wrong? I don't hear/see or feel any thing unusal when this happens. I tried driving it in the city going up hills and such, but it seems to be working perfectly fine even when the light is on. Anyway, should i be concerned about this or what? Any Help will be greatful. Thanks
99 Blazer LS Service Engine Light only when....
Jun 01, 2004
6 Replies
I would guess it's a knock sensor problem....(or maybe a knock causing said problem). But remember .... a "guess".
~KJ/TLGM
I would guess that before guessing at ANYTHING he should just go to Autozone or NAPA and have the codes read for free. To the OP, get the computer scanned and post the EXACT codes that are retreived before you buy anything the parts store guys will try to sell you.
Doc
If it's been three weeks since the code was set, it might have been erased by now. Most codes are "self'erasing" after a successful number of duty cycles without the problem. If the code was set just a few days ago, then ya, it'll still be there. Have it scanned, if no codes are present, wait until the next time the SES light comes and and make sure you get her scanned within a few days.
Get the exact codes (will look like PO###) and post them here.
Doc
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