Engine Coolant Temperature Sensor - B3000, B4000 & Tribute 3.0L

WARNING: This page is about a different car, the 2003 Mazda Tribute, 2003 Mazda B4000, 2003 Mazda B3000, and 2003 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

Engine Coolant Temperature (ECT) sensor uses a 5 volt reference voltage during engine operation. To check ECT signal voltage, backprobe between signal terminal and ground with engine running. To check sensor resistance, disconnect sensor connector and measure resistance between sensor terminals. For ECT sensor specifications, see ENGINE COOLANT & INTAKE AIR TEMPERATURE SENSOR SPECIFICATIONS (B3000, B4000 & TRIBUTE 3.0L) table. For additional diagnostic testing, see appropriate SELF-DIAGNOSTICS article.

ENGINE COOLANT & INTAKE AIR TEMPERATURE SENSOR SPECIFICATIONS (B3000, B4000 & TRIBUTE 3.0L)⁽¹⁾

Temperature °F (°C)

Volts ⁽²⁾

⁽³⁾ Ohms

50 (10)

3.51

58,750

68 (20)

3.07

27,300

86 (30)

2.60

24,270

104 (40)

2.13

16,150

122 (50)

1.70

10,970

140 (60)

1.33

7700

158 (70)

1.02

5370

176 (80)

0.78

3840

194 (90)

0.60

2800

212 (100)

0.46

2070

230 (110)

0.35

1550

248 (120)

0.27

1180

⁽¹⁾	Values may differ by as much as 15 percent.

⁽²⁾	Backprobe between signal terminal and ground with engine running.

⁽³⁾	Measure resistance between sensor terminals.