Good afternoon,
I had an engine check light come on about 2 weeks ago and the blink code read 42, which i beleive is idle control switch or throttle body sensor. I changed it last week and the check engine light stayed off for about 20 mins and was back on. I recently had an engine rebuild and am going for a remap & dyno on friday. I am needless to say a little worried.
Anyone help.

 

come on anyone?????

 

is the light coming back on when you hit high rev's?

My check engine light came on during a rr run - it was at about 7,000rpm though and the issue was just cam timing sensor, never done it on the road.

 

The light is on constantly and as i say dyno on friday. Will I do any damage???

 

No point running on a Dyno with the CEL on as you'll probably be running half boost.

 

Any reputable company wouldn't dyno a car with the management light on anyway!! OK, i know not much help. I take it you did check that it was a faulty unit and not a wiring fault or pin back up??

 

did you reset the ecu after you replaced the part??

 

I take it that the ecu is reset if the battery is disconnected for a certain amount of time??

 

yes, but depending on the year of car it is often better to use the 2 plugs under the dash (2 black and 2 green) this way you get a visual check that the ecu has been reset.

 

its a 95 wrx import. I take it these are the same wires u use to get the blink codes. If it was an electrical fault were do i start??

 

yeah its the same wires. To do the reset though, you need to connect the green as well. Cant remember the website think it is saxonfield or something it tells you exactly how to do it. once reset, go for a test drive, dont hammer it fully but do drive it on boost and then see if the cel comes on again. If it does then read the error code to see if it is the same one.

Tracing electrical faults can be a nightmare, either easy or impossible to find, prepare for lots of head scratching!!

 

There's a diagram explaining here.......

We use it for Legacys, but would think it's the same (IF not, someone please confirm)

http://legacy.manxforums.com/forums/...t=0#entry10657