2005 aveo, check engine light And "Hold" light flashing...

[azaveo]

Hey,
i have a 2005 aveo that is giving me issues. the check engine light is flashing (p0300, random misfire. i checked/cleaned/regaped the plugs) check the wires and connections, everything looks good, no vacuum leaks that i see, egr seems ok), and i also at the same time have the "Hold" light flashing, and when it does so...the tranny will not shift into 4th gear, it just stays in 3rd. however when the hold light doesn't flash the tranny shifts smooth and fine into 4th.

this is my first aveo....any idea's?

[wuwei37405]

What do you mean by "looks good"? Do you mean you visually inspected them, tested them, or replaced them? I've had plugs and wires that visually looked good but later proved to be malfunctioning and had to replaced.

[azaveo]

i was referencing visually (as it was still light out), that evening i gave the wires a shower...it was a mini lightening show. could wires cause both the p0300 AND the HOLD light to flash though? i know yes to the p0300 but i don't see how the hold light (thus transmission) would be effected by an ignition issue?

[petrified.rabbit]

yes, misfire of the coilpack can cut the rpm signal to the transmission ecu.

do the coilpack and wires.

[patricklprice]

Hes right. Any time the engine runs sluggish below a certain rpm then the ECU WILL send a signal to the transmission to NOT go into 4th gear so as to not over rev the engine. For me it was a bad Map sensor at $80. My code was #0107. It could be most any code though. A better description of this is on Answers.com under "Flash hold light" page 2.

[azaveo]

have other people experienced this issue? i can't afford to throw parts at it and find out that wasn't the issue.

[petrified.rabbit]

i have directed a few people to that as the problem.

to under simplify the issue, put start the car and mist the coil pack with water, if you see sparks, its arcing out.

[azaveo]

had you Read my reply....you'd have seen i've already done that. i also replaced the wires, with no resolution to the issue.

[petrified.rabbit]

i read your reply, you misted the wires, do you mist the coil pack?

did you read my reply where is said the coil pack misfire will cut the rpm signal to the transmission?

[azaveo]

yes misting the wires includes misting the coil pack. there was no evidence of any arcing of the coil pack...the plug wires showed some arcing. i'm going to change the plugs, and run some seafoam through it today.