Description & Operation

WARNING: This page is about a different car, the 2004 Mazda B2300, 2003 Mazda B2300, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See the following:

For 2002 models, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.
For 2003 models, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.
For 2004 models, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Cooling fan motors operate when Powertrain Control Module (PCM) determines fan operation depending on crankshaft position, Cylinder Head Temperature (CHT) sensor, vehicle speed, Intake Air Temperature (IAT) sensor, A/C switch and refrigerant pressure switch inputs. Cooling fans receive power through the cooling fan relay, which when energized, directs voltage to the cooling fan motor. See WIRING DIAGRAMS .

The Cylinder Head Temperature (CHT) sensor is mounted on the cylinder head between the No. 2 and No. 3 spark plugs and measures the metal temperature of the cylinder head. It provides the PCM with engine temperature which can be used to infer coolant temperature. The water temperature sensor, located at right rear base of the cylinder head, supplies water temperature signal the instrument panel temperature gauge only.