hey guys, my 95 bonni ssei supercharged, is running like crap. surgeing at idle, stumbling and hesitating on acceleration. i checked and replaced worn vaccum lines. it did no good. i hooked up the scanner and got two codes po118 coolent temp sensor and p0670 quad driver module 4. before i go out and replace the computer, i would like to make sure its not a short in a solinoid or something else. from my research i have dedermined quad 4 controls the ac clutch and 2 cooling fans.?? i need to confirm what the quad 4 controls, how to check if i have a failure, and if this would be causing my driveability problems. thanks very much for any help. vernon Also, the ac and cooling fans appear to be working fine...

Fix the coolant sensor. That will likely fix the running like crap issue.

The Quad 4, there'* two and it looks like you've done your homework on which items it controls for the one you have. Check the resistors on the fans, all the things you can on those items. While the pcm is the flakiest flake out there in 95, in my case...it didn't lie about a quad driver. But I did find it the hard way. Mine was the evap, BCS and TCC driver. Everything worked great...I swapped the bcs and it was like magic.

thanks bill, i got he temp sensor in and have seen some improvement in driveability. i am still getting the surge at idle..i am not positive what the quad driver module 4 controls on my year model...and think i may have a problem with my bcs.. i ran the test where you plug the vacuum line and the surging went away... i can't find a bcs anywhere online or at parts store.. i have not tried the dealer.. just giving an update and thanks again for yor help. vernon

The code you reference is the AC relay, MIL light, Low speed cooling fan, and high speed cooling fan.

The surging you mention sounds like a vacuum leak. Touch the vacuum hoses with a finger. If your finger has black vacuum stuff on it replace them. Don't forget the ones under the airbox by the charcoal canister.

Really appriciate your help on this...here is whats happening.. i replaced the bottom( Larger) vac line to the cannister and the drivability problems have gone away...But the readings on my scanner are weird. (actron cp 9145) .I erased the previous codes, drove the car and while running parked, read new codes. it came up with one history code the coolent temp code. went to view details and and it had the coolent temp fluctuating from 204 to 304 degrees. also where it says current codes, it flashed fast "yes/no, yes /no" " then on O2 again flashing fast "rich/lean rich/ lean". meanwhile, the cel is lighted and the driver information center (diagram of car) flashes the engine and chimes, stops for a few seconds and then lights and chimes again at irregular intervals.. my question is, do the mil go bad and can they be fixed or does this look like i may be needing a new computer after all? thanks again for any help. vernon

With the engine off and key on, does it show any current codes?

Could be the pcm, the down side of a pcm is there'* really no true way to say it'* definately the pcm. Do you know of anyone with a 94/95 H body in yoru area that you could swap pcm'* with to try a known good one?

with the engine off and the key turned on i am now getting system pass no codes...yet the mil light is going haywire.. yesterday while i had it running.. the scanner said no codes but i was getting the mil light and the car information had the engine bay lighted..i don't know why the quad mod 4 fault error went away.. no i really do not have anyone i can swap out with... can you tell me where the ecm is located on the care and is it difficult to change out.. looking on the web, i saw an ecm for about 85.00thanks again for being so helpfull, vernon..