CEL light on- code 9- water thermosensor
 

this light has been on since i put my motor back in after getting it rebuilt. its a code 9 for the water thermosensor. After searching, i know this is the green plug by the alternator. however, both the plug and connector seem to be in good condition. any ideas?

You could always test the sensor to make sure. After a quick search I found this
https://www.rx7club.com/forum/showth...t=thermosensor

awesome. thanks man i'll have to try it... will let you know the result once i get around to it.

would no signal to the ecm from the thermosensor cause a loss in power at all?

the ECU will default to some preset number, which probably makes it run really rich

sometimes it looks good, but the wires get tugged on and wont be making contact.

IF you backprobe the green/white wire at the ECU plug with the plug connected to the ECU, the meter should read approx 0.50 to 0.60 vdc if the engine is fully hot. IF the engine is cold it'll read over one volt dc maybe as high as two volts dc if it's a cold day.

If it reads five vodc then either one or more of the two wires on the wagter thermo sensor connector is not making contack. Pull its green plug off and look to see if both contacts in the green connector are pushed back not making contact.
Water thermo sensors are bullit proof unless you hammer on them or bust 'em open. Simple as that.

by "backprobe" you mean the positive multimeter lead on the green/white wire, and the negative lead at ground? if i had to rewire the connector where would i send each of the two wires to? one to the the ecu.... and one to.... power? ground? i won't have a chance to look at this till thursday :(

allll right, i ended up with a little free time, and pulled the alt. off, and looked at the connector. looks like the two prongs on the wire side are pushed back in. could this be from pulling on the wires while putting the engine back in? and is there any way to fix this or do i pretty much have to find another connector and wire it in?

If you can,Find any old connector..from an OLD harness that Sort of Looks like the waterthermo Connector.Take that connector and wire it in..The ONLY Difference is on the Plastic of the Connector.you will see What I am talking about when you go to put the other connecor in.Take a Sharp knife and make a groove,for the New connector and you are STYLIN.The CLIP should hold the connector in place as usual...this is a Last Ditch effort If you feel you can't get at the Prongs of the Connector,or the sensor..I've done it before,on a broken coneector and it WORKS.

thanks misterstyx.... i think i'll have to try that. and here is why:

i took a closer look at the connector, saw the prongs pushed in so far, decided to try something. took some 18ga wire, made two 1cm long pieces, completely bare except for a tiny piece of insulation to hold all the strands together. i put one piece down each of the two holes in the connector. put everything back together, went to start the car, no check engine light! went for a road test, it came back on after 20 seconds or so, meaning of course that my little wires were no longer making contact. so obviously my sensor is ok, i just need to put a new connector in there.