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 a hose that helps your car's engine breathe is either loose or broken. It's like if you had a straw in your drink, but the straw was cracked, so you can't sip properly.
The P120D code indicates an issue with the crankcase ventilation hose on Bank 1, which may be disconnected or defective.
The crankcase ventilation system helps to manage the pressure and gases within the engine's crankcase. A disconnected or defective hose can lead to improper ventilation, affecting engine performance and emissions.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Disconnected ventilation hose
• Cracked or damaged hose
• Faulty hose connections
Crankcase: The part of the engine that houses the crankshaft.
Ventilation Hose: A hose that allows gases to escape from the engine's crankcase.
• Inspect the crankcase ventilation hose for disconnection or damage.
• Check the hose connections for tightness and integrity.
• Use a smoke test to identify any leaks in the system.
• Reconnect the hose if it is disconnected.
• Replace the hose if it is cracked or damaged.
• Ensure all connections are secure and tight.
• Socket set
• Screwdriver
• Smoke machine
$50 - $150
Moderate
• Vehicle 1
• Vehicle 2
• Vehicle 3
• Regularly inspect hoses for wear and tear.
• Ensure proper installation during maintenance.
• Use quality replacement parts.
Engine Performance
• Address the issue promptly to avoid further engine problems.
• Consult a professional mechanic if unsure about repairs.
Check your vehicle's warranty for coverage on emission-related components.
This code has been more frequently reported in vehicles with over 100,000 miles.
Moderate – It should be addressed soon to prevent potential engine damage.
Driving with this issue may lead to increased emissions, which could violate local environmental regulations.
• Engine must be running.
• Vehicle should be at operating temperature.
The crankcase ventilation hose is typically located on the engine, connecting the crankcase to the intake manifold or air intake system.
Q: Can I drive with a P120D code?
A: It's not recommended to drive for long periods with this code, as it can lead to engine performance issues.
Q: How can I prevent this code from appearing?
A: Regular maintenance and inspection of hoses can help prevent this issue.
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