THE 91 VG i just got have few problems one of them is that whenever i start the car fans starts too....they dont go off no matter even if the car is cold or hot they just doesn't go off....first i thought it would be CTS sensor problem but i just changed the sensor today and fans are still running krazyy.....and ECU showing code is 13.....its 1 RED FLASH AND 3 GREEN FLASHES which is Coolant Temp sensor right?.....so i changed it but still nothing.....what else should i check to solve this problem?....thanks...

 

I assume as you're experienced 3rd gen orger you have replaced the correct sensor with another known good one. That aside the only things left are ECU and harness. If you have access to multimeter - check the voltage on CTS connector, it has to have some. Check the fuses as well to make sure ECU gets all neccessary power sources. The way it 'senses' the temperature is by supplying current to the sensor which produces voltage according to the Ohm's law. When temperature increases CTS resistance decreases so does the voltage and ECU turns on those fans at certain level. So, if ECU cannot produce that test current due to lack of one power supply, or its CTS pin is shorten to the ground it will look the same from ECU logic point of view - too hot.

 

Another possibility - fan relay got stuck in ON and ECU cannot control it anymore as it can only turn it ON and relay is supposed to turn OFF on its own. There're 3 fan relays, one for low speed and 2 - for high speed. You can start by pulling them out to see which one actually keeps fans running. Then there's ECU connector which controls those relays. If you disconnect that fans should stop. Of course, keep your eyes on the engine temperature when fans are not working.

 

thanks man...i will check all dat u told me to and will see wat happens and den i will report bak....

 

If messing with the connector and swapping sensor didn't fix the problem, I second a stuck relay.

 

i checked relays and they r on their place...how do u tell if the relay is stuck? i swapped VE working Coolant Temp Sensor and it didnt fix anything....i think CTS isnt the problem....

 

Having this same problem. based off of what my electronics teacher told me, it could potentially be the temp sensor only because, the computer doesn't know what the engine temp is so it keeps the fans running just because it's not sure. My Temp gauge under the dash is not fully functional (works 50%) of the time. [it'll jump from normal to HOT to COLD at any instant]

but based off of what you're saying..i'm not so sure..

 

Well, you can pull them out and see if the fans stop spinning. They will, almost 100%. Then you put relays back one by one noticing which one cause them to spin. When you find that listen to the sound of relay - they have to make 'click' when engaged. If relay is stuck it won't make that sound. More reliable test is of course with multimeter if you have one handy. Watch your engine temperature please when fans are not working. All relays here are only 3 cooling fans relays, not all relays in the car.

 

Your teacher spared you details . He is right, actually. Your temp gauge uses its own sensor so it doesn't affect fan operation. CTS does though.

 

i jus had that problem last night into this afternoon thats weird.I did a search on here earlier.I didnt think it was the cts until i moved it around. I must have bumped it or something cause it had jus replace my cap, rotor and spark plugs!Come to find out a had a lose connection!

 

i have my climate control out on the seat cuz its so dim i have to solder connections again....harness are hanging out...can that be the problem fan spinning? cuz IF u turn on the AC... fans spins no matter wat happens....i could connect my climate control bak and chek it but its in pieces rite now....and i will chek dat relay thing tomma....

 

do you have some extra relays setting around? Swap out all the fan relays or test them for being closed causing your continuing operation on!

 

oh i see... thanks

 

It very well could be. Try to get that thing back together and put it in. Let us know.

 

Be sure to replace the proper sensor, which is not the one with a single blade plug. Its this one:

 

ok guys i swapped and checked fan relays and they r all good...looks gud to me...ok this is wat i did.....there are 3 relays for fans rite so if i take the 3rd relay out fans doesnt stop and if i take the 2nd relay out fans totally stops and if i take the 1st relay out fans gets slower but doesnt stop and put the 1st relay bak in fans runs on their full speed.....so i swapped relays from VE to my VG ( as they r same ) but still the same...so i guess relays are okay......NOW come to the Coolant Temp Sensor, i swapped my old spare working stock sensor from VE with hoping that it would be the sensor whos giving me problems but it didnt help at all....then i saw da pic which mtcookson posted and i thought why not compare the sensors which i pulled out from da VG with the one i putted in from VE....so here it is....VG HAS A THIN NOSE CTS SENSOR AND VE HAS A FATT NOSE CTS SENSOR.....could dat be the problem? and how many volts are in the CTS connecter? Thanks guys u r helping

 

Did you plug your climate controls back in yet? Im still suspecting this to be the culprit. Should be a quick test unless you have them completely gutted.

 

no but i dont think so if climate control controls the fans i searched in FSM and theres no evidence of climate control to controlling fans neither they mentioned anywhere dat if u take the climate control out fans wont stop running....i know that if u turned on A/C then fans will run to supply aditional air....but....well i dont have climate control at the moment cuz the one i have is in pieces and sitting dere to be soldered...and i dont wanna take the climate control from VE its too much lol....i might jus went to the junk yard and grab one from dere then put it on but again i dont think its climate control....CTS jus doesnt seem right to me...

 

What is important is their resistance at the same temperature. You can put them both in the glass of water, leave it there for 5 mins and then measure resistance without taking them out of the water. I expect they will be the same.

I think the voltage will be 5V, I can check this tonight.

 

Voltage on the connector with engine off, key in ON position, sensor not connected is 4.8V. Positive contact is the right one if connector faces you with tab up.

Resistance of the sensor with warmed up engine is 300 Ohms. Fans were not running at that temperature.

If I disconnect the sensor and start the engine it starts but dies right after.

My sensor has blue connector and my JDM one was red. Red one made fans running all the time due to lower resistance. I'm not sure if the color actually means anything, just an observation.

The car is 93 SE with VE30DE engine, automatic. I bought my CTS from dealer separately.

 

dyam i aint gettin any voltages on the CTS connecter i just checked today....i think i found the problem?

 

Yep, most likely - check that ECU connector is fully inserted in ECU. Am I getting this right, Caped ?

If it is - check that all your fuses are OK, may be one of the power lines to ECU is missing.