I have a 1998 wrx sti, the engine check light comes on and off intermittently during running of the car. Also the cooling fans are always starting and stopping, even when the engine is cold. As soon as i put the key in and turn it on they start to run, this is causing the car no to run at normal temp. It hardly gets warm at all. Ive checked the code and it turns out to be 21 which is Coolant Temperature Sensor or Circuit. So ive change both cooling temp sensors the single wire one and the orange/brown colored one under the alternator. This has not cured the problem.

Does any one know what else could cause this problem, also does any one know where to find the relay for the fans so i can try to work my way back to see what is giving the ecu the signal to run the fans...

thanks

jim

 

This could happen if the CEL reader connectors are connected. Normally they would be apart during normal operation.
To start with it would be worth having your ECU read for faults.
Where are you located?
Does your car have an OBD port? I think the change over was the second half of 98.

 

harvey

thanks for the reply

I have checked the ecu codes and it gives a code of 21 Coolant Temperature Sensor or Circuit changed the sensors and even tried different ecus the fault remains. I found the relay for the fans a black one under the bonnet in the fuse box, i removed this relay and the the fans continue to run ?????. Im now thinking it must be a wiring fault ???

 

like harvey says , have you left the connectors together under the dash ??????

 

Where the replacement CTS new or used??

 

sorry no that was the first thing i checked its not that

 

Can you just confirm that the car is a version 4 STI?

Tony

 

yes mate it a 1998 import but its got a CDB

 

Where the replacement CTS new or used??

 

I used ones off my spare engine they are fairly new only done 500 miles

 

 

Where are you located? If you are not far from me I can look over your car in 15 minutes and possibly get to the root of the problem. Alternatively there might be somebody close by you happy to help. Plugging in to the OBD and reading the historic codes and checking the green and black connectors is no big deal.