I have a 2005 Equinox LT AWD and when I am driving it up a steep grade (about 2 miles long) as I get about two third's the way up it will start to misfire slightly then the check engine light will flash and when I get to the top of the grade it stops flashing. Other then that the car runs great! So anyone have this going on and fixed it?

 

if you have a scan tool check to see which cylinder is misfiring. remove the spark plug for that cylinder and see if the porcelain insulator is cracked. if it is, replace the plug and wire. if you do not have scan tool...check cylinder #5.

 

When I am pulling the grade it will start to miss and then the check engine light will flash. When I check it with my scan tool no codes come up. I will check the plugs they are only two months old with maybe 4000 miles on them. I am going to get some Seafoam and may change the fuel filter. Thanks Tech2

 

if the ses light is flashing, misfires are occurring. a factory scan tool or high end scan tool would allow you to see misfire history to isolate the misfiring cylinder.
the engine will be under load when going up hill and this will create an increased spark demand.
there was a problem for these models with cracked plugs. the wire will carbon track so it must be replaced also.


another thing to check would be fuel trim. maybe its running lean?

 

I have a high end scanner but for some reason there is no codes when I check. Maybe because the light go's off when I get to the top of the grade when the load is much lower. Thanks I will be checking the plugs.

 

the misfire data will be under special functions---misfire history.