"ac turned off for engine protection" engine code came on for coolant sensor reading high. plugged in pcm reader and it showed 168° which is accurate and the engine bay was warm obviously but not too warm. I cleared the code and put the heat on all the way just in case. any ideas?

 

If the code reader verifies proper temp, what did the gauge on the dash show? Were both fans running?

 

it was also reading around 170 at the time on the dash(it was on the tick before the operating temp tick)

 

and sorry, yes the fans were running. i have a 160 thermostat

 

so it's been awhile since it did it. but I just caught it doing it again. I notice the coolant temp guage drops all the way down and say a/c off for angina protection. I'm so confused as to why it would do this. thoughts? new coolant temp sensor too.

 

If the needle is in the normal range and then swings quickly to the extreme (cold or hot) but the engine is still at normal operating temp, then it is usually one of two things. First, either a bad harness or loose connection. Most gauges usually measure resistance to ground. If it loses continuity either from a broken wire or a loose connection, it will go cold. If it shorts to ground it will show hot.

Second thing and maybe the more likely cause is low coolant. Have you had to add coolant lately? Got any leaks? What happens is that a pocket of air gets trapped in the cooling system and sometimes will move around. If the sensor is submerged in the coolant like it is supposed to be it will give a reading but if the sensor happens to get uncovered by the air pocket, it will read cold.


The DIC code is probably set by the computer because it is not seeing the temp reading in the range it is looking for. Fix the gauge issue and I think this will self-correct.

 

yeah, since then i got an engine code for a circuit high. I can look at it to see if it's plugged in correctly and the wiring looks good. out side of that I wouldnt know what to do with it. this car also has other issues with electronics, like a blinker not working with the headlights on, having sufficient oil pressure but even with a new oil pressure sensor it reads low oil pressure randomly, brights coming on for no reason. so I'm not surprised this came up, hoping my harness isn't going to ****.

 

With multiple electronic issues like that it could be a ground. Lots of circuits share common ground points so a poor connection there could cause multiple problems. There is also a possibility of rodent damage. Sometimes mice will chew harnesses causing all kinds of havoc.

As far as the oil pressure, the sensor has a filter screen in the passage that is easily overlooked when the sensor is changed. It can become partially clogged, causing the light to come on intermittently.

 

yeah so the oil pressure issue was actually bad sensor out the box as it works fine now after putting another new sensor in, and after further inspection of my car i believe i have bubbles in my system so ill probably add some coolant and attempt to get as much bubbles out

 

just a further update on it. it's fixed now. I checked the connections and the harness for it was bad and the connectors on the plug was in pieces too which I didn't know how I didn't see previously but it's all good now. bled the coolant best I could and tightend all the coolant hose too just to be sure there wasn't an issue there

 

I recently used a vacuum filler to fill a car, then did it on my LS swap. Never going back it just works too good .... And mine is a harbor freight one.....