Cooling Pan Control System Inspection

WARNING: This page is about a different car, the 2008 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Verify that the battery voltage is more than 12.4 V.
- If the battery voltage is less than 12.4 V, charge the battery or connect the external power supply.
Connect the M-MDS and access ECT PID.
Turn A/C switch to off.
Verify ECT PID is less than 98°C {209°F}.
- If ECT PID more than 98°C {209°F}, inspect ECT sensor and related wiring harnesses.
Verify that the cooling fan does not operate with ECT PID is less than 98°C {209°F} while the ignition switch is ON.
- If the cooling fan operates, inspect for following parts and related wiring harnesses:
  - ECT sensor
  - A/C switch
  - A/C refrigerant pressure switch (High/low pressure)
  - A/C refrigerant pressure switch (Medium pressure)
  - VSS
  - A/C magnetic clutch
  - Fan control signal circuit (between fan control module terminal B and PCM terminal 1W)
    - If the all items are normal, replace fan control module.
Verify the cooling fan operates while the A/C switch to ON with the ignition switch at ON position.
- If the cooling fan does not operate, inspect for following:
  - A/C switch
  - A/C refrigerant pressure switch (High/low pressure)
  - Fan control module power supply circuit
  - Fan control module GND circuit
  - Fan control signal circuit (between fan control module terminal B and PCM terminal 1W)
    - If the all items are normal, replace fan control module.

Verify that the cooling fan operates with following table.

COOLING FAN OPERATING REFERENCE

PCM terminal 1R voltage

B+ (off)*

0V (ON)*

Cooling fan speed

Middle speed

High speed

⁽¹⁾	A/C refrigerant pressure switch (Medium pressure) condition

If the cooling fan operation is not specified, inspect for following:
- A/C refrigerant pressure switch (Medium pressure)
  - If the A/C refrigerant pressure switch (Medium pressure) is normal, replace fan control module.

Turn A/C switch to off.
Start the engine and idle it.
Verify that the cooling fan operating speed increases relative to ECT PID increases.
- If the cooling fan speed does not increase inspect following:
  - ECT sensor (characteristic)
    (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [LF, L3] .)
  - Fan control signal circuit (between fan control module terminal B and PCM terminal 1W)
    - If the all items are normal, replace fan control module.