FAQ: Engine Coolant Temperature & Fan Turn-On

If your coolant temp sensor were bad, you'd easily see it in the temp gauge, or by scanning.

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'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
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'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
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AA wrote:: If your coolant temp sensor were bad, you'd easily see it in the temp gauge, or by scanning.

always scanning. the temps dont look strange to me.. but i have tested wiring and relays and i cant explain why my fans are auto starting.

my temp control in the cabin always flashes on start for about a minute before it stays solid.. readings seem fine but not sure why it blinks at start?

freak

Is your AC on?

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch
^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown

AA wrote:: Is your AC on?

no.

charlieRobinson wrote:: my temp control in the cabin always flashes on start for about a minute before it stays solid.. readings seem fine but not sure why it blinks at start?

If your control head is blinking when you start the car, there is something wrong with it, and there are codes stored for it. The display blinks when there's a fault.

"When a system fault occurs, the VF display on the climate control assembly will flash one time per second for 100 seconds."

If the HVAC system thinks the refrigerant pressure is high it will run the fans.

Abaddon wrote:

charlieRobinson wrote:: my temp control in the cabin always flashes on start for about a minute before it stays solid.. readings seem fine but not sure why it blinks at start?

If your control head is blinking when you start the car, there is something wrong with it, and there are codes stored for it. The display blinks when there's a fault.

"When a system fault occurs, the VF display on the climate control assembly will flash one time per second for 100 seconds."

Interesting...
http://buickforums.com/forums/threads/31579-Automatic-Climate-Control-blink-codes
1. Press & hold the OFF, AUTO, and RECIRC buttons for 1 second.

2. the DTC's will display for 2 seconds each and then return to normal operation.

There are 24 DTC's listed in the manual ; 18 start with B; 6 start with U.

18 "body" codes, and 6 "communication" codes.

held the 3 buttons but nothing happened. tried with key in run, while running. while temp was flashing and once it was solid. display never changed or showed an error code.

I never said it would work, I just clarified what the codes "B" and "U" were....

Did you try holding the buttons down, then turning the key ON

» Set fan turn on temperature
» Engine coolant
» Overheating? (bad coolant temperature sensor)
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