The Quick Answer above is the generic definition. What follows is the model-specific detail for the Mercedes-Benz models that log P0021.
DTC/P0021·Mercedes-Benz
P0021 on Mercedes-Benz: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)Mercedes-Benz
P0021 on a Mercedes-Benz means the intake camshaft on bank 2 is positioned more advanced than the ECU commanded it to be. The variable valve timing system on bank 2 is not responding correctly, typically due to oil flow issues, a faulty bank 2 VVT solenoid, a stretched timing chain, or a worn cam phaser. The code only appears on V6, V8, V10, and V12 engines.
Typical repair cost, all makes€60 - €6000
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Mercedes E-Class
2005-2024The M276 V6 sets P0021 frequently due to bank 2 camshaft adjuster magnet failure. Mercedes adjusters are 250 to 400 EUR per side. The M278 V8 has similar issues. Use only MB-approved 229.5 or 229.51 oil to avoid recurrence. Sticky adjusters can sometimes be cleaned, but replacement is more reliable.
What causes P0021 on a Mercedes-Benz?
Beyond the generic causes listed on the main P0021 page, these are the patterns noted for Mercedes-Benz models:
Mercedes E-ClassM276 V6 bank 2 intake adjuster magnet failure
Mercedes E-ClassM278 V8 bank 2 timing chain wear
How to diagnose P0021 on a Mercedes-Benz with OBD2
Follow these steps to pinpoint the root cause of P0021:
- Check engine oil level and condition. Low, dirty, or wrong-viscosity oil is the most common cause of P0021. Use only the manufacturer-specified oil approval and change if overdue
- Use a scan tool to monitor live cam phasing data on bank 2. Compare the actual versus commanded intake cam advance angle. Deviations over 5 to 10 degrees confirm a real timing fault
- Locate the bank 2 intake VVT solenoid (typically on the bank 2 valve cover or front of the bank 2 cylinder head). Measure resistance (6 to 13 ohms typical) and inspect the mesh filter screen for sludge
- Listen for cold-start rattle from the bank 2 side of the engine. A timing chain rattle on bank 2 specifically points to chain or tensioner wear on that bank
- If the oil and solenoid are good, suspect timing chain or guide wear. A workshop will need to remove the bank 2 valve cover for inspection, or check timing chain wear with a service tool
How much does P0021 cost to fix on a Mercedes-Benz? (EUR)
Estimated repair costs for P0021 in EUR, compiled across makes. Expect Mercedes-Benz parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Codes related to P0021
These codes are often seen alongside P0021 or point to related issues, on any make:
Looking for the full P0021 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0021 guideSkanyx · Mercedes-Benz
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