Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has found a problem with the fan that cools the engine. It's like when a fan in your room isn't working because it's not plugged in properly.
The P0691 code indicates that the vehicle's computer has detected a low voltage condition in the circuit controlling the first cooling fan.
P0691 is triggered when the Powertrain Control Module (PCM) detects a low voltage condition in the electrical circuit that controls the first cooling fan. This could be due to a short circuit, a faulty fan relay, or issues with the fan motor itself.
• Engine overheating
• Check Engine Light illuminated
• Cooling fan not operating properly
• Faulty cooling fan relay
• Wiring issues such as short circuits
• Defective cooling fan motor
PCM: Powertrain Control Module
Relay: An electrical device that opens or closes a circuit
• Inspect the cooling fan relay and its connections.
• Check the wiring for shorts or damage.
• Test the cooling fan motor for proper operation.
• Replace the faulty cooling fan relay.
• Repair or replace damaged wiring.
• Replace the defective cooling fan motor.
• Multimeter
• Relay tester
• Basic hand tools
$100 - $300
Moderate
• Ford Focus
• Chevrolet Silverado
• Honda Accord
• Regularly inspect fan wiring and connections.
• Ensure cooling system maintenance is up to date.
• Replace faulty relays promptly.
Electrical Circuit Issue
• Do not ignore the Check Engine Light; seek professional diagnosis.
• Avoid driving the vehicle if it shows signs of overheating.
• Schedule regular vehicle maintenance to prevent electrical issues.
Repairs may be covered under the vehicle's powertrain warranty if applicable.
P0691 has been a common issue in vehicles with aging cooling systems or electrical components.
Moderate – Addressing this code promptly can prevent engine overheating.
Driving with a malfunctioning cooling fan can lead to engine damage and safety hazards.
• Ensure the engine is at operating temperature.
• Test the fan operation with the A/C on to ensure maximum load.
The cooling fan is typically located at the front of the engine bay, attached to the radiator.
Q: Can I drive my car with a P0691 code?
A: It's not recommended to drive with this code as it can lead to engine overheating.
Q: How can I prevent a P0691 code?
A: Regular maintenance and inspection of the cooling system can help prevent this issue.
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