went out to my C5 after work, it had been sitting outside all day. ambient temperature is about 15F. started the car and had OIL TEMP. LOW on the DIC, I had oil temp displayed before. I was going to wait until about 50 before I headed home.
dic says LOW
coolant temp begins to climb
oil LOW
I start driving. car gets fully up to temperature, oil temp LOW
restarted the car, nothing. finally got home. shut it down. sat for about 5 minutes when I went back to pull the codes, turned on the ignition and it says 185 degrees.

no specific codes but as usual I had a few loss of communication codes. I always seem to have those. RFA: loss with BCM, PCM, and IPC.

all other gauges worked correctly.
what is wrong with this beautiful and extremely problem prone vehicle now? and how much is it going to cost?

in the event the temp gauge fails again where is the sensor located and how hard/costly is it to replace?

for something else totally bizarre and probably not related. after turning the car back off from reading the codes I hear a sound that sounds like the actuators for the AC/Heat ducts trying to move or moving all by themselves...car and HVAC was completely shut down at that point. wtf?

and while we're at it, what gives with these loss of comm codes? I usually see several of them. RDCM frequently has some. yet other than what's mentioned everything seems to be working fine. windows work, door locks, gauges except for this one time with the oil temp, BCM functions etc.

Thanks.

 

I guess the GM engineers did not think most C5 owners, would be driving around in 15 degree weather.....

At that ambient temperature, the PCM is right on the edge of thinking the circuit is open, as it will throw a code (and low oil temp message) at below 14 degrees F. The sensor resistance increases as temperature decreases.

 

but shouldn't the actual temperature appear once the oil warms up? I even stopped after it was fully warm and restarted the car and the temp low message remained. it wasn't until I finished the whole trip and went back to check the codes that the temp displayed properly again. I'm pretty sure I've had this car out in colder weather than this before, I don't recall this ever happening.

 

I think this is what you need

http://forums.corvetteforum.com/c5-t...rt-number.html

 

Your car needs a Blanky...........http://www.globalindustrial.com/p/hv...campaignId=T9F

 

doesn't sound too bad. would you happen to know where its located?

I also don't want to replace it unless I have to of course. it started working again and as far as I know its only done that once. probably means its on its way out.
is there any truth to the earlier suggestion that its supposed to show Low below 14 degrees? and if so would I be correct in assuming that if it were working properly it should have displayed the temperature from 15 degrees and up? its possible the oil was colder than the outside temp indicator was saying. usually when I start eh car when its cold the oil temp indicator shows a lower temperature than the climate control says outside is.

I couldn't find the replacement procedure in the shop manual for some reason. anyone know what its listed under in the index? its not listed in engine/oil/anything...found the pressure sensor info, oil level sensor info, but no oil temp.

 

In the few years I have read these forums, I have not read a post on oil temp sensor issues. I would ignor it for now as the LOW temps were playing a major role in your sensor readings.

 

Its right above your oil filter. I found my original post: http://forums.corvetteforum.com/c5-t...h-display.html

 

I would take a close look at the battery and chassis ground connections, before replacing any parts.

 

Your description and Lucky's post, particularly this part...

would point to faulty sensor wiring. If a wire comes loose, it will essentially be interpreted as infinite resistance hence the low temp warning msg and erratic behavior. Make sure all the wiring at the sensor is clean and tight before you start buying parts.

 

.....and would precipitate a B1543.

 

Thanks all! I'll keep this info handy just in case. today's drive home 18* according to the climate control, 18* according to oil temp sensor right after startup. it seems ok but it probably means the sensor is on its way out. at least I really hope its just the sensor if that's the case.

I've checked the grounds on the car several times throughout ownership. they are all fine.

no B1543 code, so hopefully if it was not just a transient issue (could get lucky right?) then its just the sensor. been through the oil pressure sensor once. this one sounds much easier! if anyone has one handy, can you post a pic?

 

You can't get to the ground for oil temp............not saying it's an issue for you....just a little info......for those interested.

http://forums.corvetteforum.com/c5-t...t-problem.html

 

Its been a while since I saw something similar on my 03 but I think you are describing a normal condition. Probably 4 years ago I had a similar occurrence on my 03 and the whole time I drove the car I had a low oil temp message. After stopping and restarting the engine I saw the oil temp.

The loss of communication codes don't mean much except a periodic message failed to get through. It may have gotten through the next time it was sent but the code isn't reset. That is why they don't indicate a problem on the DIC. If you are having a problem with the car and are getting a lot of these codes then they may indicate something. Other than that I never pay attention to them.

Bill