P0480 still

[05TB90TROOPER]

I have replaced water pump, fan clutch, thermostat, ECT sensor and cleaned throttle body and scanned vehicle everything checks good except code comes back at start up every time. Engine temp on scan tool is 199.7 with a/c on. O2 sensors show good and cat shows good. any suggestions I need to get thru emissions here in New Jersey. Thinking of PCM tune but don't have the extra money right now and my second vehicle is down at the time.

 

[05TB90TROOPER]

I have also tested the fan clutch by stopping it and it is working

 

[Mooseman]

You won't break anything if the fan is running OK but the light is annoying. You did download the manuals so with the schematics and a DMM, you'll have to check each circuit from the PCM connector to the relay, the grounds and from the relay to the fan connector. Check for opens and shorts.

 

[05TB90TROOPER]

You won't break anything if the fan is running OK but the light is annoying. You did download the manuals so with the schematics and a DMM, you'll have to check each circuit from the PCM connector to the relay, the grounds and from the relay to the fan connector. Check for opens and shorts.

I know it won't break anything, but have a RED failed inspection sticker and need a good sticker

 

[Mooseman]

I don't know why because this has absolutely nothing to do with emissions. Just the engine would overheat if the fan fails to work. Anyway, without getting a tune, you have to check the wiring.

 

[05TB90TROOPER]

I don't know why because this has absolutely nothing to do with emissions. Just the engine would overheat if the fan fails to work. Anyway, without getting a tune, you have to check the wiring.

frikken New Jersey, can't inspect vehicle with a CEL on. And the only thing they check is emissions now. No mechanical

 

[Sparky]

Sigh that sounds like fun.

Probably start having to look at the wiring. Maybe start with yanking the relay and test the relay by itself with a 9V battery and DMM to make sure the relay functions correctly. Also, with the relay pulled you can check to see if the PCM is indeed grounding the relay coil by testing that terminal at the socket with a DMM while the engine is running. At least rule out the control side anyway.

 

[05TB90TROOPER]

I also put in a new relay, so will check wiring from fuse box to plug

 

[Mooseman]

Maybe start with yanking the relay and test the relay by itself with a 9V battery and DMM to make sure the relay functions correctly.

Can't test it like that. It's a PWM relay.

 

[Sparky]

.... dang stupid fancy relays....

</grumpy old fart>

 

[RTTBLT1]

May sound dumb...but have you tried replacing the Radiator Cap?...maybe the system isn't correctly pressurized???
Sounds as if you have replaced most of the cooling components so if not the Cap being the culprit I would also suspect a Wiring issue.

 

[djthumper]

Check fuse 20 it has been known to thrown the code if it is blown.

 

[05TB90TROOPER]

Didn't know that used PWM, alot of foreign vehicles are using it on lighting now. 1 wire going to taillight and pulses tell what function to light up.

 

[Mooseman]

It's also used on the headlights for the DRL. I think it modulates them to 60% . That's why they use the same relay since it uses PWM to modulate the fan.

 

[05TB90TROOPER]

Thanks everyone, The fuse was blown also. I have been doing this to long to not have checked the fuse previously

 

[05TB90TROOPER]

Thanks everyone, The fuse was blown also. I have been doing this to long to not have checked the fuse previously

And passed inspection this morning !!

 

[JimInRadfordVA]

Ladies and gentlemen, we have another happy customer!