Temp is reading -37 all the time

cmccuist · 01-05-2005, 07:28 AM

The readout on my daughter's '95 318 says -37 F (or -4 C) all the time. Is there a sensor that needs to be replaced? Anyone else ever had this problem?

Jared at Pelican Parts · 01-05-2005, 08:33 AM

Outside temp sensor. Should be in the brake cooling duct in the front of the car..

Jeron · Jeron's Garage

Sound's like the sensor to me.

Should be in the front right brkae cooling duct. You might also test for shorts.

Tim Polzin · 01-05-2005, 11:32 AM

Quote:

Originally posted by cmccuist
The readout on my daughter's '95 318 says -37 F (or -4 C) all the time.

If it reads -37 on F and -4 on C, something may be wrong with the display. -37F should be about -38C (at -40, they both read the same).

Tim

cmccuist · 01-05-2005, 11:52 AM

I noticed that -40F = -40C.

Is there a way to check if the sensor is operating correctly or if it's just the computer dying?

Jeron · Jeron's Garage

I believe the sensor will provide varying resistance across the range of temperatures. I dont know if it needs power to function. Either try to test the resistance installed with the power on or pull the sensor and test at varying temperatures.

My guess is that -37 is the bottomed-out temp and the resistance will be zero.

Tim Polzin · 01-06-2005, 06:47 AM

I guess the part I was questioning is why was there a difference in display values between C and F? If the display shows -37F, it should read approx -38C, if the temp shows -4C, it should read about 24F. In this case, he was getting two different values (-37F AND -4C)

Tim

cmccuist · 01-06-2005, 07:06 AM

I will pull the sensor this weekend and do a resistance check at various temps. I hope the computer isn't fried. The clock light is also out, so I can replace that also.

blkongry · 01-06-2005, 07:09 AM

If the computer is fried, you can usually pick one up for under $100 on Ebay... I've seen several on there.

Jeron · Jeron's Garage

I guess I was just assuming that he mistyped the -4C and meant -40C.

Be careful buying on Ebay. Just make sure the computer you buy is what you need because there are many variations.

LeRoux Strydom · 01-10-2005, 04:57 AM

The sensor may just be unplugged either at the sensor end or at the computer end, or the wiring is damaged. It is rare for a thermocouple to go bad, unless physically damaged by stone impact or something else. The symptom (-max deg display) is typical of an open circuit on a t/c.

On my wife's RHD car the sensor is in the pass side brake duct (right side if you stand in front of the car looking at it). I don't know if it is the same on a LHD car.

LeRoux