VandyFan

CHEVY 2003 Tahoe LT

My rearview mirror says "OC" on the temperature display. The compass display is working properly.

I think it may be a problem with the ambient temp sensor but don't know how to locate the sensor. Can someone advise: (a) how to locate the sensor (b) test to see if this is indeed the problem (c) replace the sensor (d) anything else of particular use in this situation.

MANY THX!!!

John86

should be behind ur grille assembly some where. don't think u can really test this sensor that i know.
i have a Diag.chart for u so if u can PM me ur email addy then i will send it to u as an attachment.

mcorona

Hey,
I have the same problem - The temperature display says "OC" but the compass is working fine. What could be the problem? Does anybody know how to fix this, please?

kevinkpk

I think oc means open circuit.

DYNAY2K

My 03 Tahoe's Mirror is Also Possessed.
It also shows OC as well as SC., the Compass works fine.
I would assume that the OC means Open Circuit, and the SC means Short Circuit... ;o?
In any event, I finally got around to removing the grill and replacing the Ambient Temp Sensor today 12/13/14,
...Wouldn't ya' know it,...It Didn't fix the problem. (
I even wiggled the plug around in the back of the mirror to see if something in the contacts may be problem...No Luck.... ~
I guess the next thing is to replace the mirror,...Or Just keep it turned off... /
Any help would be appreciated.

kevinkpk

I suppose since I am subscribed to this thread (although I thought I was done with this forum) I will give it a stab. I believe what you have in the sensor is an RTD (resistance temperature detector). This is a resistor that varies with temp, in other words the colder it is the lower the resistance, and vice versa. The (I assume BCM) sends a 5 volt signal to it, and reads the voltage back from it, and displays that as temperature. If it were me, I'd not assume the new part was good, and put an ohm meter on it. If the resistance is "something" I'd assume it is the 5 volt from the BCM issue, i.e. not getting the 5 volts to the device, that could be a loose dirty connection. Is this a two or three wire connector?
I am sure if Allen in NE has time, he will correct me.

DYNAY2K

Hi Kevin
Thanks for the reply, I believe your explanation is correct.
I actually had the new part might be bad in the back of my mind, when I purchased it from the dealer, the baggie was opened and re-taped shut.
When I installed it, and I saw no change as the mirror had the same reading as with the original part, I assumed that the one I just purchased was or might have been bad, before replacing my grill / etc, I took it back and exchanged it for an New Unopened one, It also read the same...
I did all the wire checking I could possibly reach, made sure the terminals were clean and dry, even wiggled them while on the see if I could generate a another reading...NOTHING
Unless something else pops up, I'll be starting the search for a replacement mirror.
Thanks for your thoughts...

kevinkpk

I'd first check the plug to see if you have voltage (with key on) to the sensor.