OEM Part Number: 22630-44B20
Price: $20.00-$30.00

On the 4th Generation Maxima engine the Engine Coolant Temperature Sensor is located in the water outlet tube close to the engine end of the upper radiator hose. There are two sensors in that area. The one nearest the hose is for the dashboard temperature gauge. The ECTS, the one you’re interested in, is right next to the the gauge sending unit. There is a good picture of these sensors in the Haynes manual on page 3-7.

With the engine cold, disconnect the ECTS and measure its resistance. Reconnect the ECTS, start the engine, run it until fully warmed up. Stop the engine, and repeat the resistance measurement. The “warm” reading should be a much lower value than the “cold” reading.

The specs for the ECTS are:

• Engine coolant temperature 68F, ECTS resistance 2.1 – 2.9 Kohms
• Engine coolant temperature 194F, ECTS resistance 0.24 – 0.26 Kohms

Replacements Symptoms/Notes:

• Below about 30 degrees idle will die if I don’t keep my foot on the gas at startup. Once engine is warm it’s OK.
• Just a quick update for anyone having the same problem. Replaced the CTS (ECU Temp sensor in the picture) and guess what? My multi-year cold start problem is OVER! She runs like new again. Over $1000 spent on MAF, TB cleaning, and more and all I needed to do was replace a $9.00 sensor.