Cooling fan system operation (at idle)
WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.
COOLING FAN SYSTEM OPERATION (AT IDLE) DESCRIPTION
| Engine condition | Cooling fan relay No.1 | Cooling fan relay No.2 | Cooling fan relay No.3 | Cooling fan No.1 | Cooling fan No.2 | |
|---|---|---|---|---|---|---|
| Engine coolant temperature 97°C {208°F} or less | OFF | OFF | OFF | OFF | OFF | |
| Engine coolant temperature 97°C {208°F} or more (until 94°C {201°F} or less) | ON | OFF | OFF | Low speed | Low speed | |
| Engine coolant temperature 101°C {213°F} or more (until 98°C {209°F}) | ON | ON | ON | High speed | High speed | |
| A/C and fan switches are on. | The refrigerant pressure switch (medium pressure) is off. | ON | OFF | OFF | Low speed | Low speed |
| Engine coolant temperature 101°C {213°F} or more or the refrigerant pressure switch (medium pressure) is on. | ON | ON | ON | High speed | High speed | |
| ECT sensor malfunction | ON | ON | ON | High speed | High speed | |
- Connect the WDS or equivalent to the DLC-2.
- Verify that DTC P0480 or P0481 is not displayed.
- If DTC P0480 and/or P0481 are displayed, perform DTC inspection.
- Access the ECT PID.
- Verify that the ECT PID is 97°C {208°F} or less .
- Verify that the A/C switch and fan switch are off.
- Start the engine and let it idle.
- Verify that the cooling fans are not operating.
- If the cooling fans are operating at low speed, inspect for the following:
- Cooling fan relay No.1 (stuck closed)
- Wiring harnesses and connectors (cooling fan relay No.1-PCM terminal 5X) (short to GND)
- If the cooling fan No.1 is not operating, but cooling fan No.2 is operating, inspect for the following:
- Cooling fan relay No.3 (stuck closed)
- Wiring harnesses and connectors (cooling fan relay No.3-PCM terminal 5AD) (short to GND)
- If the cooling fans are operating at low speed, inspect for the following:
- Warm up engine 97°C {208°F} or more
and verify that the cooling fans are operating at low speed.
- If cooling fans are not operating, inspect for the following:
- Cooling fan relay No.1 (stuck open)
- Wiring harnesses and connectors (battery -cooling fan relay No.1-cooling fan relay No.2) (open)
- Wiring harnesses and connectors (main relay-cooling fan relay No.1 PCM terminal 5X) (open)
- If cooling fan relay No.1 is operating at high speed, inspect for the following:
- Cooling fan relay No.2 (stuck close)
- If cooling fans are not operating, inspect for the following:
- Stop the engine.
- Disconnect the ECT sensor.NOTE:
- When the ECT sensor connector is disconnected, the PCM stores DTC P0118.
- Start the engine and let it idle.
- Verify that the cooling fans are operating at high speed.
- If the cooling fans are operating at low speed, inspect for the following:
- Cooling fan relay No.2 (stuck open)
- Cooling fan relay No.3 (stuck open)
- Wiring harnesses and connectors (open circuit at battery-cooling fan relay No.3-cooling fan No.2-GND)
- Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No.2-PCM terminal 5AD)
- Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No.3-PCM terminal 5AD)
- If cooling fan No.1 is operating at high speed, but cooling fan No.2 is not operating, inspect for the following:
- Cooling fan relay No.3 (stuck open)
- Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No.3-PCM terminal 5AD)
- If cooling fan No.2 is operating at high speed, but cooling fan No.1 is not operating, inspect for the following:
- Cooling fan relay No.2 (stuck open)
- Wiring harnesses and connectors (open circuit at main relay-cooling fan relay No.2-PCM terminal 5AD)
- If the cooling fans are operating at low speed, inspect for the following:
- Clear the DTC from the PCM memory.