Engine Management Light On And Off

[fern86]

hi all

im looking for some answers on a strange prob im having im sorry if the topic has been covered before and if it has can someone post link. I have a 99 is200, a while back engine management light came on i had the car diagnosed and it came back as a missfire but the car was fine and no missfires it came on whilst on the motorway but i didnt feel anything strange either. the mechanic that diagnosed it switched it off, he also said that these cars dont correct themselves by switching the light off if the prob is no longer there. it must be removed by a diagnostic machine. a while later i was on a motorway again and at around 80mph the light flashes but didnt stay lit up but this was only at 80mph, less than 80 there was no light and more than 80 there was no light, then eventualy the light stayed on with trc flashing, if i disconnect Battery light is no longer on, but once on motorway again same thing happens till light stays on. has anyone got any ideas as to what i can do if its anything serious?

thanks

fernando

[ColinBarber]

we really need to know what error code(s) is (are) being produced. Just resetting the ECU isn't really helping, and FYI for nearly all the error codes if the fault isn't detected after 3 ignition/engine running cycles the management will go out automatically.

It may well be an Oxygen sensor error or misfire detection.

[fern86]

Ok im going to get the car in and get codes, thanks very much for the help, are those two probs u mentioned relatively easy to sort? il get back to u soon. thanks again

[Deafluggs]

Hi mate.

Don't go to the garage to get the codes read, they'll charge you the same amount to read the codes than it costs to purchase a decent OBD2 code reader.