P1387 VTC Solenoid Circuit Malfunction
The P1387 code indicates a fault in the variable timing control (VTC) solenoid #1 circuit. This solenoid adjusts intake valve timing to optimize engine performance and reduce emissions. The engine control module (ECM/PCM) detects an electrical anomaly in the solenoid circuit, such as out-of-range voltage, a short circuit, or an open circuit. When the ECM cannot properly actuate the VTC solenoid, the variable timing system is disabled, forcing the engine to operate on base valve timing, which reduces efficiency.
01. Most Common Causes
- Faulty or internally shorted VTC solenoid
- Short or open circuit in the solenoid wiring
- Corroded or bent pins in the solenoid electrical connector
- Low or degraded engine oil
- Internal ECM/PCM failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance and fuel economy
03. Step-by-Step Diagnosis
Scan for codes and verify P1387 is present
Inspect VTC solenoid connector for corrosion or damage
Test solenoid resistance and compare to specifications
Check engine oil level and condition
Test circuit continuity and voltage at the solenoid
1. Frequently Asked Questions
Is it safe to drive?▼
Yes, but you may notice reduced performance and fuel economy. It's best to diagnose and repair soon to avoid potential engine damage.
How much does it cost to fix?▼
Typically $150 to $400, including parts (solenoid $50-$150) and labor.