Bad coolant sensor

When i bought the jeep the h.u.d. keeps telling me there is a bad coolant sensor. Well im about to go on a 5hour trip next week so i would like to have it fixed. I see that these are a common problem so which sensor is bad? Where is it located? Any advice here would be great.


Also the engine is the 5.2L v8

When i bought the jeep the h.u.d. keeps telling me there is a bad coolant sensor. Well im about to go on a 5hour trip next week so i would like to have it fixed. I see that these are a common problem so which sensor is bad? Where is it located? Any advice here would be great.


Also the engine is the 5.2L v8

On my '97 GC 4.0L it is the sensor on the coolant overflow tank. i unplugged it and clean the connector contacts and so far it has not given me any more trouble and that was 2 weeks ago. Some people have taken the sensor out and cleaned it and that as solved the problem also.

Well i replaced the one up by the thermostat and the light is still on, i think i will try cleaning the overflow sensor.

What year is your jeep? Pre 95 5.2L had 2 coolant sensors, 1 right next to the T-Stat housing. and 1 right next to the heater hose.

I am not exactly sure their purpose, but I believe 1 is for the dash guage and 1 is for the computer.

It is a 96, I can see in the manual that there are two on either sides of the thermostat but there is only one on the right side (the one i replaced) and on the left side there is a plug. I cleaned the one in the overflow tank and the light is still on. So where is the second on it?

Did they move the second one in 96?

Could this be correct.... under the hood, center, front engine area, below valve cover, mounted in water outlet???

Did they move the second one in 96?

95 and later, they just got rid of the one. Prolly ran the one thru the PCM to the Dash Guage.

I have a 98 and it's right by the thermostat housing. Just look where the top radiator hose goes into the engine block. Before you replace anything, check the engine temp gauge. If it seems to be working you're wasting your time replacing the sensor. I replaced both sensors (one by the thermostat and the coolant level sensor), 40 bucks for nothing. From what I've read on all the posts on this problem it's a slight voltage drop causing the problem. The fix seems to be that you just have to find the slightly corroded connector causing the problem. It could be by the sensor or a connector to the PCM. Good luck, I'm still trying to find my little corroded gremlin!