FixVault

Coolant Temperature Sensor

Disconnect negative battery cable. Remove coolant temperature sensor. Suspend coolant temperature sensor in a container filled with water. Place a thermometer in container. Connect ohmmeter between coolant temperature sensor connector terminals. See Fig 1 . Gradually heat water and check sensor resistance. See COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace coolant temperature sensor.

Fig 1: Testing Coolant Temperature Sensor
G94D47764Courtesy of MAZDA MOTORS CORP.
COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS

Coolant Temperature Ohms
2.0L
A/T
68°F (20°C) 35.5-39.2k
140°F (60°C) 7.17-7.93k
176°F (80°C) 1.13-1.25k
M/T
68°F (20°C) 2.20-2.70k
104°F (40°C) 1.00-1.30k
140°F (60°C) 0.50-0.65k
176°F (80°C) 0.29-0.35k
2.5L
68°F (20°C) 2.20-2.70k
176°F (80°C) 0.29-0.35k
196°F (91°C) 0.23-0.24k
207°F (97°C) 0.19-0.21k
226°F (108°C) 0.14-0.15k
230°F (110°C) 0.13-0.14k