TEST 3: Checking Fan Operation With The Engine Running (With A Scan Tool)
NOTE: This test only applies to the 1996 OBD II equipped Toyota Camry.
In this test section, we're gonna check the performance of the radiator fan switch as the engine runs.
For this performance check, we need to use a scan tool with "live data" capability so that we can monitor the engine coolant temp.
If the radiator fan switch is OK, both fans should activate when the engine coolant temp reaches a temperature between 220°F and 225°F.
IMPORTANT: Do not proceed with this test if, during TEST 2, the fan motors failed to activate when the radiator fan switch was disconnected and the key was turned to the ON position.
NOTE: The scan tool will display a higher temperature for the activation of the radiator fans. This happens because the scan tool reads the coolant temperature measured by the Engine Coolant Temp (ECT) sensor, which is located in a hotter part of the engine. While radiator fan switch 1 is designed to activate the fans at 208°F and above, your scan tool will show a higher activation temperature due to the ECT sensor's location. This discrepancy is normal and nothing to worry about.
These are the test steps:
- 1
Reconnect the radiator fan switch to its connector.
- 2
Check the coolant level in the radiator.
If it's low, top it off with coolant or water before proceeding to the next steps. - 3
Connect your generic scan tool to your Toyota Camry's diagnostic link connector.
- 4
Access the "live data" feature on your scan tool and locate the "ECT" (Engine Coolant Temperature) or "COOLANT" PID (see photo above).
- 5
Start the engine and let it idle.
- 6
Monitor the ECT temperature on your scan tool as the engine idles.
- 7
Both cooling fan motors should turn ON when the ECT temperature reaches between 220°F to 225°F.
- 8
If the radiator fan motor hasn't turned on by 225°F, turn the engine OFF immediately to avoid overheating.
Place a house fan over the engine to cool it down.
Alternatively, you can disconnect the radiator fan switch and turn the key to the ON position to force the fans to activate and cool the engine down.
Let's take a look at your test results:
CASE 1: The fan motors turned ON at the indicated temperature range. This the correct and expected test result.
This test result tells you that the radiator fan switch is good and not the cause of the engine's overheating problem.
If your Toyota Camry is overheating, I suggest you test the engine coolant thermostat and doing a blown head gasket test.
CASE 2: The fan motors DID NOT turn ON. This confirms that the radiator fan switch is not functioning and needs to be replaced, if you have:
- Confirmed that the combined amperage draw of both fans is under 30 Amps.
- Confirmed that the operation of both fans by directly applying 12 Volts and Ground to them.
- Confirmed that the radiator and condenser fan fuses are OK (TEST 1).
- Confirmed that the operation of both fans by disconnecting the radiator fan switch and turning the key to the ON position (TEST 2).
- Confirmed in this test section that the fans are not activated at the indicated temperature.
TEST 4: Checking Fan Operation With The Engine Running (With A Infrared Thermometer)
In this test section, we're gonna check the performance of the radiator fan switch as the engine runs.
For this performance check, we'll use an infrared laser thermometer to monitor the temperature of the radiator fan switch.
If the radiator fan switch is OK, both fans should activate when it reaches a temperature between 190°F and 205°F.
IMPORTANT: Do not proceed with this test if, during TEST 2, the fan motors failed to activate when the radiator fan switch was disconnected and the key was turned to the ON position.
Let's get started:
- 1
Reconnect the radiator fan switch to its connector.
- 2
Check the coolant level in the radiator.
Top it off if needed before proceeding. - 3
Start the engine and let it idle and warm up to operating temperature.
- 4
Point the laser directly at the metal base of the radiator fan switch.
- 5
Monitor the temperature of the radiator fan switch.
Use the infrared thermometer to track its temperature. - 6
Check fan activation.
When the radiator fan switch's temperature reaches 208°F or above, both fan motors should turn ON to cool the engine coolant. - 7
If the fans don't activate turn off the engine.
If the temperature exceeds 210°F, turn the engine OFF immediately to avoid overheating. Place a box fan on the engine to cool the engine.
Alternatively, you can disconnect the radiator fan switch and turn the key to the ON position to force the fans to activate and cool the engine down.
Let's interpret your test result:
CASE 1: The fan motors turned ON at the indicated temperature range. This the correct and expected test result.
This test result tells you that the radiator fan switch is good and not the cause of the engine's overheating problem.
If your Toyota Camry is overheating, I suggest you test the engine coolant thermostat and doing a blown head gasket test.
CASE 2: The fan motors DID NOT turn ON. This confirms that the radiator fan switch is not functioning and needs to be replaced, if you have:
- Confirmed that the combined amperage draw of both fans is under 30 Amps.
- Confirmed that the operation of both fans by directly applying 12 Volts and Ground to them.
- Confirmed that the radiator and condenser fan fuses are OK (TEST 1).
- Confirmed that the operation of both fans by disconnecting the radiator fan switch and turning the key to the ON position (TEST 2).
- Confirmed in this test section that the fans are not activated at the indicated temperature.
More 3.0L Toyota Camry Tutorials
You can find a complete list of 3.0L Toyota Camry tutorials and wiring diagrams in this index:
Here's a sample of the tutorials you'll find there:
- How To Test Engine Compression (1992-2006 3.0L V6 Toyota Camry).
- How To Test For A Blown Head Gasket (1992-2006 3.0L V6 Toyota Camry).
- How To Test The TPS (1997-2001 3.0L V6 Toyota Camry).
- How To Test The MAF Sensor (1997-2001 3.0L V6 Toyota Camry).
If this info saved the day, buy me a beer!
