Subaru check engine light

tekaholics, Jun 20, 11:30pm
I own a 94 subaru legacy TS-R, when I bought it, the previous owner told me the check engine light comes on and stays on. He had taken it to mechanics and they said the engine is good, to pay no attention to the check engine light.this made me curious and google what could be worng with it.this is what the car does:

*The radiator fans stay on 24/7 when car is started and driving.
*Doesnt start first time in the morning, takes about a good 7 starts before it kicks over

I have googled the check engine light and done the thing with the green plug underneath the dash. There is also a black plug. When I pluged in the green plug, the check engine light went away, I thought it was ment to blink.
So my question is.Am I doing it right to diagnose the problem with my car! Thank you in advance.

intrade, Jun 20, 11:35pm
ummmmm if the check engine light is on that means there is a fault code registered.there will be something wrongyou can check it your self. seems down or gone . that site used to have full info on how to get codes out with the plugs and what the morescode means

tekaholics, Jun 20, 11:40pm
yep I got the troublecodes from another websites, it was posted on anothe similiar question like mine. Copied and paste them to my computer. The green plug that should be plugged in to diagnose the problem, took my check engine light away. Its supposed to blink and give me the codes. 1 long blink equals 10 and 1 short blink equals 1. Is that right!

tmenz, Jun 21, 1:54am
If the air conditioning is switched on then the fans will run full time!

bigfatmat1, Jun 21, 5:52am
its the two black plugs you plug in not the green try the black ones the fans come on &stay on when a fault is logged

ceebee2, Jun 23, 5:05am
Engine light will represent either a rich mixture / lean mixture or if the engine has back fired a damaged AFM. Simple as that.

Cheers CeeBee (Auto Tech 30 years)

malp, Jun 23, 6:13am
I have this problem with my subaru as well, I have had car for over 2 years and it has come off and on the whole time.

intrade, Jun 23, 6:19am

bigfatmat1, Jun 23, 6:22am
Check engine light will come on because of a sensor failureor out of range reading only there is 14 sensors on auto 12 on manual. Light will not come on if engine has backfired running to rich or to lean. unless these paramaters are caused by sensor failure. This is a very old car with basic diagnostics. and very easy to diagnose and fix. nothing complicated about these vehcles.

zephyrheaven, Jun 23, 8:02am
Dont wish to flame you bud, but thats dead wrong

zephyrheaven, Jun 23, 8:03am
fans running all the time sounds like ecu temp sender fail to me, but as said black plug to black plug / key on / count flashes

bigfatmat1, Jun 23, 9:11am
as above also fits your symptoms. code 21 two long flashes 1 short

noswalg, Jun 23, 9:13pm
Thats right, plugging the 2 green plugs together will clear the stored fault codes hence the check engine light going away, obviously the problem is still there so it will trigger the code again. I had a 95 outback that had a recurring fault 23 (MAF sensor) showing which I put down to the K&Npod filter that was on it as it would only come on when engine revved above 5500-6000 RPM. That was my diagnosis, I never really looked into as it wasn't causing problems. I had 80000km's trouble free motoring out of that car.

tekaholics, Jun 24, 12:20am
Yep have checked the check engine light, and it is code 21.coolant temperature sensor. Any chance of where it is or how to fix that! thanks.

bigfatmat1, Jun 24, 12:37am
yep is burried on top of motor r/h front just to side of manifold pretty easy to replace. cost about 30-40 $ from memory. Make sure car has water in it if it does replace sensor.

motorway, Jun 24, 12:57am
Push the choke in.

stephenb1, Jun 24, 5:20am
dont worry they have to many knock sensors my been coming on when the car hits a pot on then trunes off its been doing this for 3 years. grandwagon 1997 2.5 , sudlab says they do it alot. but if it stays on best to get it looked at by sublab.

bigfatmat1, Jun 24, 5:24am
they have 1 knock sensor. Should be fixed knock sensors are a easy fix bout $140 + labour it should not come on if ya car hits a a pot on the trunes whatever that may be. when it senses a knock it retards the timing not bring the light on.

lugee, Jun 24, 6:41am
Your description fits faulty coolant temp sensor perfectly. It seems the sensor is wrongly reporting a high engine temp, which is causing the fans to run all the time. This would also cause the difficult cold start, as the ECU will be thinking it is a warm start and not a cold one, and not richening the mixture accordingly.

tekaholics, Jul 26, 3:56am
Thanks for that lugee. My partner is replacing the sensor tomorrow so thanks heaps guys, hopefully no more cold starts in the mornings.