Crankcase Ventilation System Fault
There’s a problem in the crankcase ventilation system causing excessive pressure or vacuum.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The crankcase ventilation system helps manage pressure in the engine by directing airflow. If it's not working, the engine can’t breathe properly, leading to leaks or oil issues.
What the computer is actually seeing
The Engine Control Module (ECM) monitors pressure differences and airflow rates in the crankcase. If it detects pressure over 3 kPa (0.43 psi) or vacuum below -1 kPa (-0.15 psi) for more than 5 seconds, it triggers this code.
What a healthy reading looks like
Crankcase pressure should be between -1 kPa and 3 kPa under normal conditions.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check the engine oil level; it should be within the normal range, not overfilled.
- 2Inspect the PCV (Positive Crankcase Ventilation) valve and hoses for blockages or damage. Test the PCV valve operation by blowing through it (it should allow air in one direction).
- 3Look for leaks around the oil fill cap and inspect for wear or improper seating.
- 4Perform a vacuum test on the crankcase; it should stay within expected values under normal operating conditions (not exceed -1 kPa).
- 5Check the seals around the crankshaft and valve covers for oil leaks, indicating a failure in sealing.
Common causes
- Clogged PCV valve or passages
- Oil fill cap leaks
- Crankshaft seals or valve cover gasket failures
- Overfilled engine oil
- Faulty turbocharger push on diesel engines
Typical repair cost
$$$ - $$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's moderate severity; you can drive short distances but should fix it soon to prevent further engine damage.
Will this problem come back after repairs?
If the root cause is properly addressed—like fixing leaks or unclogging the PCV—you shouldn't see it return.
Why do I see this code with low engine power?
Poor crankcase ventilation can affect engine performance and efficiency, leading to reduced power output.
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