P0021 – BMW DTC

BMW DTC P0021 – ‘A’ Camshaft Position – Timing Over-Advanced or System Performance (Bank 2)

DTC P0021 meaning on BMW

The DTC P0021 code on a BMW indicates that the ‘A’ camshaft position is over-advanced or there is a performance issue in the timing system of Bank 2. This means that the camshaft timing is not within the expected parameters, which can lead to various engine performance issues.

BMW DTC P0021 symptoms

Symptoms of a DTC P0021 on a BMW may include:

• Check Engine Light (CEL) illuminated on the dashboard
• Decreased fuel efficiency
• Engine misfires
• Rough idling or stalling
• Lack of power or acceleration

BMW DTC P0021 causes

Common causes of a DTC P0021 on a BMW include:

• Incorrect camshaft timing due to a faulty camshaft position sensor
• Issues with the variable valve timing (VANOS) system
• Timing chain or belt problems
• Engine oil issues, such as low oil level or dirty oil

BMW DTC P0021 seriousness

Ignoring a DTC P0021 on a BMW can lead to further engine damage and potentially more costly repairs. It is important to address this issue promptly to prevent any long-term consequences on the engine’s performance and longevity.

How to diagnose DTC P0021 on BMW

To diagnose a DTC P0021 on a BMW, you can perform the following steps:

1. Use an OBD-II scanner to retrieve the fault code and check for any other related codes
2. Inspect the camshaft position sensor and wiring for any damage or loose connections
3. Check the VANOS system for proper operation
4. Inspect the timing chain or belt for any wear or damage
5. Check the engine oil level and condition

How to fix DTC P0021 on BMW

To fix a DTC P0021 on a BMW, you may need to:

1. Replace the faulty camshaft position sensor
2. Repair or replace any damaged wiring related to the camshaft position sensor
3. Address any issues with the VANOS system, such as replacing solenoids or seals
4. Inspect and replace the timing chain or belt if necessary
5. Ensure the engine oil is at the correct level and replace if dirty

How to erase DTC P0021 on BMW

To erase a DTC P0021 on a BMW, you can:

1. Use an OBD-II scanner to clear the fault code after the underlying issue has been addressed
2. Drive the vehicle for a short distance to allow the system to recheck and confirm the repair
3. Verify that the Check Engine Light is no longer illuminated

Recommended tools & DTC Scanners for BMW

Best Diagnostic App for modern BMWs: BimmerLink

Recommended Bluetooth adapter for Bimmerlink: OBDLink CX

Cable adapter for Bimmerlink: Enet Cable USB Type C

For older BMWs we recommend: Autel AutoLink AL319 (2024 version)

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

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