trying to diagnose a component problem. on a 95 ssei. first the car started surging at idle and and would hesitate some on acceleration. not real bad and the car was still driveable. thought it might be vacuum leak but it was not. this went on for severl weeks. then last week the emc kicked two codes.. po118 and po670 these are coolent temp sens and quad driver module 4 fault. replaced the coolent temp sensor.seemed to drive some better but eventually the emc kicked the same exact code for the new sensor. and i am still getting surge and hesitation. seems unlikely the new sensor would have exact same problem as the old one... my understanding of the quad driver module is that on my car it controls a/c relay, mil, low speed cooling fan and high speed cooling fan. all of these components seem to be ok except the mil. for example, the car information center is acting up.. on the diagram of the car, the engine is lighting and chime is ringing. it comes on intermittantly as if there were a short. then yesterday i drove the car about 5 mile and the mil light on the dash kicked on.. today with the actron 9145 scanner, with the ignition on and the engine off, i get system pass no codes .. my question is..is there a way to check the mil system.. is there an actuator, relay,control module, or something else i can check and correct. or would this be a problem with the emc? also, would the driveability problems have anything to do with these codes? thanks very much for any help. vernon

Can you please define your terms: mil and emc?

just so we are on the same page.

Thanks.

whoops! i ment ecm (enigine control module) and mil is malfunction indicator lamp. Also i did clear up the driveability problem... turned out to be a vacuum leak after all, it was on the lip of the metal flex tube that is part of the egr system. fixed wirh cold weld and it has made all the difference. i am still getting the lightshow and after the drive, with the car in park, engine running,i observed both cooling fans turning off and on and running sporadically...thanks again for any input. vernon