420A 2gNT P1490 Code, Fans Not Working.

[stevoharris420]

I have a p1490 code is that to do with a temperature sensor please help me . Fans not kicking on I know one goes to the ac but rad fan not turning on

I have a p1490 code can anyone please help me make it go away my car runs rough idk what to do the rad fan will not work at all . And I've tested fan it's good Nd changed relay also . Please help if ya guys can

 

[luv2rallye]

Did Nd put in the correct relay type? If yes perhaps harness/pin issue. Start checking the low speed fan control relay voltages. Assuming you have a 420A (but not the 1996), the radiator fan relay (L01 in engine fusebox slot A-11X, which is middle relay of the upper relay row of the two rows of relays) should always have +12v on the red/black wire, and +12v on the blue/red when key is on, and 0v on the green/black (from PCM) when it turns the fan on, {note the white/black goes to the fan}. You can test the relay/fan operation by grounding the green/black when the key is on - radiator fan should go on.

 

[stevoharris420]

Did Nd put in the correct relay type? If yes perhaps harness/pin issue. Start checking the low speed fan control relay voltages. Assuming you have a 420A (but not the 1996), the radiator fan relay (L01 in engine fusebox slot A-11X, which is middle relay of the upper relay row of the two rows of relays) should always have +12v on the red/black wire, and +12v on the blue/red when key is on, and 0v on the green/black (from PCM) when it turns the fan on, {note the white/black goes to the fan}. You can test the relay/fan operation by grounding the green/black when the key is on - radiator fan should go on.

I also didn't state I have no ac in the car as well its I did a a. Delete to the car . Could that be the problem I'm gonna go check and see what I can find out

 

[Sirius1995]

I also didn't state I have no ac in the car as well its I did a a. Delete to the car . Could that be the problem I'm gonna go check and see what I can find out

If everything else is working, maybe install a on/off button for the fan? but rad fan should kick in if relay/fuse is ok, and signal from temp sensor is coming out, try change the coolant tempature sensor, it's cheap to replace and cuts off 50% of what can be wrong, if nothing above don't work, then your fan motor is dead, you can try to feed 12V for it and see if it spins

 

[Sirius1995]

oh and code p1490 is for evap surge line, most likely a stuck valve or loose gas cap, or slanted evap hose, nothing to do with the engine cooling

 

[luv2rallye]

oh and code p1490 is for evap surge line, most likely a stuck valve or loose gas cap, or slanted evap hose, nothing to do with the engine cooling

NO - where do you see that? My factory Mitsubishi book (and here https://www.dsmtuners.com/threads/code-avalanche-oh-my.534058/#post-153800542) shows it's "Low speed fan control relay circuit".

 

[Sirius1995]

NO - where do you see that? My factory Mitsubishi book (and here https://www.dsmtuners.com/threads/code-avalanche-oh-my.534058/#post-153800542) shows it's "Low speed fan control relay circuit".

I probably mistyped the code last night when I was checking the post, my bad on that part

 

[Sirius1995]

If everything else is working, maybe install a on/off button for the fan? but rad fan should kick in if relay/fuse is ok, and signal from temp sensor is coming out, try change the coolant tempature sensor, it's cheap to replace and cuts off 50% of what can be wrong, if nothing above don't work, then your fan motor is dead, you can try to feed 12V for it and see if it spins

I still stand for this statement, but start with feeding 12v to the fan and see if it spins, these rarely ever broke but sometimes faulty relay or a short wire might burn the fan motor, if it spins, try change the relay and coolant temperature sensor, you can bypass relay with a paperclip first just to see if it works with that, if new relay don't fix it but it works with the paperclip bypass, you have a short somewhere

 

[stevoharris420]

Still have a p1490 can anyone help me I check the whole harness no wires are naked and new sensors rad fan isnt working at all and I've check 12v power to the fan and it works fin

I also rebuilt a motor it's a 420a eclipse motor. I have traced all wires nothing is naked and touching . And new sensor

 

[Sirius1995]

Still have a p1490 can anyone help me I check the whole harness no wires are naked and new sensors rad fan isnt working at all and I've check 12v power to the fan and it works fin

Did you skip my replies bro?

 

[stevoharris420]

No like I've said I've check it all today I looked all through the wiring harness no wires are touch and the fan works with 12v power it comes on

 

[Sirius1995]

No like I've said I've check it all today I looked all through the wiring harness no wires are touch and the fan works with 12v power it comes on

Well did you try to bypass the relay?

 

[stevoharris420]

How would I do that

 

[Sirius1995]

You take the relay out and connect the ends together with paperclip or wire which are pointing same way but on opposite site on the relay

 

[stevoharris420]

Can you pm me a picture of what your talking about

 

[Sirius1995]

I'm busy at work right now but just Google relay bypass with paperclip, they also sell bypass kits in part stores which has on off switch on it if that's easier for you

 

[stevoharris420]

Yep it comes on . But still cant figure out why it's not without being jumped and it's still throwing p1490 code

 

[Sirius1995]

Yep it comes on . But still cant figure out why it's not without being jumped and it's still throwing p1490 code

Trace ground wire from relay and see if that connection is good

 

[stevoharris420]

Okay I'll get back with you soon appreciate you taking the time to help me

 

[Sirius1995]

Okay I'll get back with you soon appreciate you taking the time to help me

Sure thing, and I know that electric stuff is frustrating to track, I just fixed this issue at Camaro where #2 cylinder injector was open all the time when running, found the issue after long time tracing the harness and watching wiring diagrams

 

[stevoharris420]

Do you know what wire would be the ground to the relay

The pin had came out of the ecu . Thanks for the help guys

I fixed the problem if anyone else is having this problem check the black and green wire going to the ecu

 

[Sirius1995]

I'm glad you found it and were able to fix it!