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Chris (aka- Moose)
Chris (aka- Moose), Buick Technician
Category: Buick
Satisfied Customers: 48363
Experience:  16 years of experience
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2006 lacrosse 3.6 cxl fans seem to be delayed turning on.

Customer Question

2006 lacrosse 3.6 cxl fans seem to be delayed turning on. i see the temp is reading 195 and no fans. relays are fine. seems the ecu isnt sending a signal to turn on. i have a relay with noncover and can switch them on manually. seems they come on late. the dash temp needle is leas than half. and on the obd2 feed i can see coolant temp is 212
Submitted: 1 year ago.
Category: Buick
Expert:  Chris (aka- Moose) replied 1 year ago.
Welcome, I'm Chris (aka Moose). I normally log in after 3 pm central. Please make sure to let me know exactly what is needed from me so I can provide EXCELLENT 5 STAR service. With the AC on are the fans running?Does it overheat?At what temp are the fans coming on at?The computer tells the low speed fan to come on at 213 F and the high speed fan at 222 FThe thermostat begins to open at 194 and is fully open at 225.Do realize the temperature of the coolant in the engine is going to be greater than that of the coolant in the radiator. So until the thermostat has displaced that hot coolant into the radiator, there is no need to run the fans just yet and once that swap has occurred if that coolant that was in the radiator enters and fills the engine and ends up being less than 213, the fan will still not come on. -------------------------------------------------------------------------------------On your screen at the top you should see a rating 1-5 stars and a green submit button. Please make sure to select one and press submit. I am not compensated by the website unless a customer rates. Rating only pays me from the deposit you have already made, it does not charge you more, nor close the post. Also all follow ups are free and welcome.Thanks Chris
Customer: replied 1 year ago.
ok well the ac fan doesnt come one, with the ac on.
Customer: replied 1 year ago.
until the main fan come
in
Customer: replied 1 year ago.
that is the main concern. the ac blows warm air on the coldest setting until the main fan come on and the ac fan also comes on
Customer: replied 1 year ago.
dtc code 0480 pops up
Expert:  Chris (aka- Moose) replied 1 year ago.
Does the AC work good once the fan comes on? If so what engine temp does the fan come on at?Which fan is coming on, the low or high speed?It sounds like the low speed fan that should come on first and with the AC on, is your issue.
Customer: replied 1 year ago.
does each speed have it own relay? for each fan? i dont want to swap out the fan motor without need
Expert:  Chris (aka- Moose) replied 1 year ago.
There are 3 fan relays. We are not up to enough information yet to start changing parts.Are you able to respond to my prior comments?
Customer: replied 1 year ago.
ac is cold wen the fans come in. temp is sometime varies but i here them on at over 215
Customer: replied 1 year ago.
an the ac starts to cool
Customer: replied 1 year ago.
i see two relay with 4 prongs thiose work well i havnet seen the third. is a five prong?
Expert:  Chris (aka- Moose) replied 1 year ago.
Here is a fan relay diagram to help. https://dl.dropboxusercontent.com/u/90220402/fanrelay.pdfSince you have a fan coming on at 215 that is the low speed fan. That means the ECM is controlling the fans correct based on ECT readings. Though its not commanding the fan on based on the AC commanded on. Will your scan tool show if the ECM is getting a AC on request signal?
Customer: replied 1 year ago.
no i have simple code reader
Expert:  Chris (aka- Moose) replied 1 year ago.
Earlier you wrote "and on the obd2 feed i can see coolant temp is 212" How did you get that reading, was that a different scan tool used?
Customer: replied 1 year ago.
i have obd2 gauge plug in read the temp and a few other parameters
Customer: replied 1 year ago.
Expert:  Chris (aka- Moose) replied 1 year ago.
Ya, that tool will not do what we need. So based on the fan coming on at 215 that means the low speed fan is working, though you need to confirm that from the wiring diagram seeing which fan is getting powered. If it is in fact the low speed fan coming on and not the ECM noticing a low speed fan issue and commanding the high speed fan instead. That means the ECM is your most likely culprit with the diagnostic tools you have.
Customer: replied 1 year ago.
can i run a signal to the relay directly from the ac pressure switch?
Customer: replied 1 year ago.
would instill get a po480
Customer: replied 1 year ago.
to a18
Customer: replied 1 year ago.
is it 5v
Customer: replied 1 year ago.
c18 is the signal
Customer: replied 1 year ago.
so i can get signal from the what other fuse or relay in the fusebox?
Customer: replied 1 year ago.
that is on while ac is on
Expert:  Chris (aka- Moose) replied 1 year ago.
Once you told me the scan tool you have, I knew you would not be able to do the tests for this code, stuck on step 2, which is why I did not provide the test steps for this code shown here. https://dl.dropboxusercontent.com/u/90220402/0480.pdfThis code can indicate the ECM, wiring, relay, or fan to blame.A18 at fan relay 1 should be battery voltage.C18 at fan relay 1 is a ground signal from the ECM to energize this relay and power the fan, but the ground comes from relay 2I do not know how to wire it up a different way.
Expert:  Chris (aka- Moose) replied 1 year ago.
Hello again Chris here,1) When customers come to Just Answer the website and the experts want them to have a great 5 star experience.2) We also want them to be so pleased that they come back for future needs.3) I have the feeling you were not pleased with my help because the post was not rated and or you need me to help more. If so please do reply.4) I have an option for an additional fee to upload diagrams, repair guides, find a repair facility, or call you if that would help. Thanks Chris