Cooling fan not working solution A6

Cooling Fan Not Working - Audi A6 C7 (2011-2018)

If you're experiencing an issue with the cooling fan not working on your Audi A6 C7, it's essential to address this promptly to prevent engine overheating. Below is a detailed guide to diagnose and fix the problem.

Step 1: Visual Inspection

• Tools Needed: Flashlight
• Procedure:
  1. Check for Obstructions: Ensure that there is nothing physically blocking the fan blades. Look for debris or signs of damage.
  2. Inspect Wiring and Connectors: Examine the wiring harness and connectors leading to the fan for signs of wear, corrosion, or disconnection.

Step 2: Check Fuses and Relays

• Tools Needed: Fuse puller or needle-nose pliers, multimeter
• Procedure:
  1. Locate the Fuse Box: Refer to the owner’s manual for the exact location of the cooling fan fuse and relay.
  2. Inspect the Fuse: Pull the fuse for the cooling fan and check if it’s blown.
  3. Test the Relay: Swap the cooling fan relay with a similar relay in the fuse box to see if the fan starts working.

Step 3: Test the Cooling Fan Motor

• Tools Needed: Multimeter, jumper wires
• Procedure:
  1. Direct Power Test: Disconnect the fan motor connector and apply direct battery voltage to the fan motor using jumper wires. If the fan runs, the motor is functional.
  2. Check Voltage at Connector: Use a multimeter to check for voltage at the fan connector when the engine is hot and the fan should be running.

Step 4: Check the Cooling Fan Control Module

• Tools Needed: Diagnostic scanner (OBD-II), multimeter
• Procedure:
  1. Scan for Error Codes: Use an OBD-II scanner to check for any error codes related to the cooling system.
  2. Test the Module: If you suspect the cooling fan control module, test it by checking for input signals from the Engine Control Module (ECM).

Step 5: Inspect the Engine Coolant Temperature Sensor

• Tools Needed: Diagnostic scanner, multimeter
• Procedure:
  1. Check Sensor Output: Use the diagnostic scanner to monitor the temperature readings from the sensor.
  2. Test Resistance: Disconnect the sensor and measure its resistance at various temperatures to ensure it’s functioning correctly.

Repair Instructions

Fix 1: Replace Blown Fuse or Faulty Relay

1. Replace any blown fuses with the same amperage rating.
2. Replace a faulty relay with a new one.

Fix 2: Repair or Replace Cooling Fan Motor

1. If the fan motor does not run with direct battery power, replace the motor.

Fix 3: Replace Cooling Fan Control Module

1. If diagnostics point to a faulty module, replace it with a new OEM part.

Fix 4: Replace Coolant Temperature Sensor

1. If the sensor is faulty, replace it to restore proper fan operation.

Final Checks

• After repairs, start the engine and allow it to reach operating temperature to confirm the fan activates correctly.
• Check for any recurring error codes and clear them with a scanner.

Safety Precautions

• Always disconnect the battery before working on electrical components.
• Be cautious around moving parts and hot engine components.

By following these detailed diagnostic and repair steps, you should be able to resolve the cooling fan issue on your Audi A6 C7. If the problem persists, it may be advisable to consult with a professional automotive technician.