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 is having trouble talking to the part that tells it if the four-wheel drive is on or off. It's like when a walkie-talkie isn't working well, and you can't hear what your friend is saying.
The P279F code is triggered when the vehicle's powertrain control module (PCM) detects a low voltage signal from the 4WD range signal circuit.
The 4WD range signal circuit is responsible for sending information about the 4WD system's operational status to the vehicle's PCM. A low signal indicates a potential issue with the circuit, such as a short or open circuit, or a problem with the 4WD range switch or sensor.
• 4WD system not engaging or disengaging properly
• Warning light on the dashboard
• Decreased fuel efficiency
• Faulty 4WD range switch
• Damaged wiring or connectors in the 4WD range circuit
• Malfunctioning PCM
PCM: Powertrain Control Module
4WD: Four Wheel Drive
• Use an OBD-II scanner to confirm the code.
• Inspect wiring and connectors for damage or corrosion.
• Test the 4WD range switch for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty 4WD range switch.
• Reprogram or replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Wiring repair tools
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Tacoma
• Regularly inspect 4WD system components.
• Keep electrical connections clean and secure.
• Perform routine maintenance checks.
Sensor Issue
• Avoid using 4WD until the issue is resolved.
• Consult a professional mechanic for diagnosis and repair.
Check with your vehicle manufacturer for warranty coverage on drivetrain components.
This code has been associated with issues in vehicles with electronic 4WD systems, particularly in models with high mileage or frequent off-road use.
Moderate – It is recommended to address this issue soon to ensure proper 4WD functionality.
Driving with a malfunctioning 4WD system can lead to reduced vehicle control and safety hazards, especially in adverse conditions.
• Vehicle in park or neutral.
• Engine running at normal operating temperature.
The 4WD range switch is typically located on the transfer case, which is mounted underneath the vehicle between the front and rear axles.
Q: Can I drive my car with the P279F code?
A: It's possible to drive, but it's recommended to get the issue fixed to ensure your 4WD system works properly.
Q: How can I reset the P279F code?
A: You can reset the code using an OBD-II scanner, but it's important to fix the underlying issue first.
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