P1381 Code: Meaning, Symptoms, Causes & Fix

Overview

Symptoms

• loss of power at mid/high RPM
• engine noise or unstable timing
• rough running or misfire

Common causes

• CAN bus wiring fault affecting variable cam timing overadvanced (bank #1)/ misfire detected - no communication with bcm
• Network termination or gateway fault
• Connector pin damage/corrosion or harness stress near related components

How to diagnose P1381

1. Confirm P1381 and capture freeze-frame data with a professional scan tool.
2. Inspect wiring, connectors, and grounds related to variable cam timing overadvanced (bank #1)/ misfire detected - no communication with bcm for obvious defects.
3. Check CAN high/low integrity, network termination resistance, and module wake-up status.
4. Check for related DTCs to identify the root-cause chain before replacing parts.
5. After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code P1381

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with P1381?

Most vehicles can be driven short-term with P1381, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

1. Repair obvious wiring/connector faults first to prevent repeat parts replacement.
2. Address the root fault mode (communication) in the variable cam timing overadvanced (bank #1)/ misfire detected - no communication with bcm circuit/system.
3. Apply the required relearn/adaptation procedure if specified by service information.
4. Road-test and verify P1381 remains cleared under the conditions that originally set the code.

Fix options

• Scan all modules for communication chain faults.
• Stabilize voltage supply and module grounds.
• Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$300-$1400

Common mistakes when diagnosing P1381

• Replacing parts without verifying voltage, ground, and signal integrity first.
• Ignoring related stored/pending codes that indicate upstream faults.
• Skipping post-repair verification drive cycle and readiness checks.

P1381 in common vehicles

P1381 appears across makes such as BMW, Mercedes-Benz, Audi, Volvo. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes P1381?

P1381 is commonly set by communication faults affecting variable cam timing overadvanced (bank #1)/ misfire detected - no communication with bcm.

How much does it cost to fix P1381?

For P1381, repair costs are typically $300-$1400 depending on exact root cause, labor rates, and part quality.

Can I clear P1381 without repair?

You can clear P1381 temporarily, but the code usually returns until the underlying fault is corrected.

Helpful tools

• Estimate repair cost
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