Chrysler Repair: coolant sensor voltage too low-04 2,4cyl code 0117, 2004 chrysler sebring, hottest day of the year

Question
QUESTION: check engine light went on and according to the computer it said coolant sensor is too low. Can you tell me what causes this situation. This happened last night and this a.m., I had it checked.and the mechanic disconnected it and said it just happens sometime for no reason. He said if it goes on again bring it in. I drove to work and it was ok. He also checked the anti freeze level and it was ok and the hoses were ok. thanks in advance

ANSWER: Hi Lew,
It could have been a temporary air bubble in the cooling system at the sensor for example. Let me know if it happens again, but tell me the year and engine size then.
Roland

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QUESTION: Everything was ok until yesterday. I drove the car for about a mile and it went on. The same thing happened the first time, that is I only drove a short distance when the light went on. Since it first happened, I drove to Cols from the Clev area and back and drove on Sunday, the hottest day of the year and it never went on. This is a 2004 Chrysler Sebring 4cyl. I am going to have the sensor replaced today in hopes this solves the problem. Do you have suggestions ?   thanks in advance

Answer
Hi lew,
The sensor could be the problem, but also the signal wire from the sensor to the engine controller could be shorted to ground. So if you aren't doing it yourself ask the mechanic to verify that the tan/black wire is not shorted intermittently to ground by shaking the wire harness while measuring the resistant between and ground. If that doesn't seem to be the case then the sensor is suspect.
Roland