I am having an electrical issue with my 2016 Z51 Stingray. I recently installed headers, cold air intake and 160 deg t/stat and then had it tuned. After a couple of months I'm having an issue where as I'm driving all of a sudden the A/C, temp gauge and active rev match stop working. Everything else works fine with no loss of power from the engine. If I shut the car off the radiator fan continues to run. I have to disconnect battery to reset everything. Any ideas what could cause this?
Thanks

 

May be the tune is causing it to act up. Maybe contact the tuners maker, and ask if they know anything. Good luck.

 

Had it been raining out, or in wet conditions?

Dale

 

I took it back to the tuner the first time it happened. He had it for 3 days and couldn't find anything wrong.

 

No rain, there seems to be nothing in common when it happens.

 

Just a guess, but look under the car and see if there is any wiring that is touching, rubbing against the headers. The heat may have damaged some wiring.

 

The tuner supposedly checked all that when he had it, that's one of the first things I thought of.

 

Just a suggestion but if you have been around corvettes very long and begin to experience electrical issues it usually comes down to the battery beginning to fail. My 14 C7 battery failed at the 2 year mark and yours is in that range also. You may be using a battery tender to keep your battery at 100% but if not, you should be. Most of us get those electrical gremlins just before battery failure. Good luck, keep us posted.

 

^^^^^ battery gremlins are a thing with our cars and now it's getting cold and that puts another hurt on the battery^^^^^

 

I think you are going to need to visit your tuner again. With a 160 degree thermostat the engine temp sensor doesn't report the engine coming up to temperature as quickly as expected under some driving conditions so the engine controller has to consider that the sensor may have failed. Under these conditions it will generally zero the temperature gauge, disable AC, engage engine cooling fan at max, and disable certain other engine functions. This is done to protect against engine overheating because the controller no longer trusts the readings from the temp sensor.

 

A properly working cooling system has no need for a 160 degree thermostat. All that's going to do is reduce your gas mileage and performance by not letting the head run at the temperature the GM engineers intended it to.

If you "need" a 160 thermostat not to overheat, even when driven vigorously, then you need to solve your other cooling system problems starting with loss of pressure. Water at 0 psi boils at 212. A 50/50 water coolant mix, pressurized to 7-12psi by a working radiator/tank cap won't boil till well over 250 degrees. But one pinhole, one loose hose clamp, ANY loss of pressure and you get coolant boiling inside the head and overheating issues. Steam and coolant vapor bubbles won't move heat from the head to the radiator and often "vapor lock" whatever coolant would otherwise circulate. Problem is compounded when owners try and run 100% coolant which doesn't move as much heat as a 50/50 mix.

Replace your 160 thermostat with the 180 or whatever GM originally installed in your car, pressure test your cooling system, it should hold 10psi for at least a half hour and fix any leaks. Put a new Stant cap on it for good measure.

 

My tuner suggested the same thing, replaced with new AC Delco battery and bought a battery tender. Because of thanksgiving the car sat for two weeks. I took it out this past Sunday and the same thing happened.

 

 

 

The symptoms described by the OP are nothing new. Depending upon the operating conditions with a 160 degree thermostat the engine will not come up to temperature as rapidly as expected and that is why the fan remains engaged, engine temp shows zero, etc.

It will happen with any thermostat if it fails open and happens commonly with a lot of 160 thermostats when ambient temperatures are low AND the driving style allows the cooling system with a wide open thermostat to stay near its 160 degree operating point. If ambient conditions are hot enough and/or driving conditions load the cooling system sufficiently that the coolant will heat up to near normal even though the thermostat is open below the ECM expected operating point and then this error won't occur.

Either your thermostat has failed open or due to the colder winter conditions the engine warmup profile is now meeting those conditions to set this error. You can change your battery, oil, or anything else you like but the problem will persist until either the tune is changed to ignore this under-temp condition or a different thermostat is installed.

On edit: These sorts of issues are common when vehicles are operated in a manner outside that assumed by the manufacturer. I got in the habit of plugging in the block heater of my 2001 GMC Sierra diesel whenever the temp was in the mid-30 to below range for easier cranking and faster cabin heat. When I bought its 2006 replacement I got a DTC with associated check engine light after a couple of months of ownership. With the 2006, GM was using various sensors to check each other and with the block heater plugged in for only a few hours WHEN the temperature was above freezing the ECM decided there was a mismatch between several temperature sensors causing it to set a DTC, lock out second overdrive, and limit engine RPM to 1,800 RPM. Sometimes these sensor cross checks fall into the category of what the British call, "too clever by half".

 

I will look into that with my tuner. The only issue with the temp is that I live in south Florida and so far the car has not been driven in anything less than probably 65 deg. The last time this occurred outside temperature was around 85 deg.

 

It is possible your thermostat is failing aggravating the issue but some 160 degree thermostats will consistently create this issue when driving conditions don't allow engine warmup in the time frame expected by the controller.

Here is one thread from the tech section describing this issue, there have been several others: https://www.corvetteforum.com/forums...t-working.html