P266B: Rocker Arm Actuator Position Sensor Circuit Range/Performance Bank 2
The P266B code indicates that the Engine Control Module (ECM) has detected a signal from the rocker arm actuator position sensor on Bank 2 that is outside the expected range or performance parameters. This sensor monitors the position of the rocker arm actuator, which controls variable valve timing or cylinder deactivation. A fault can cause incorrect valve timing, leading to reduced engine performance, fuel economy, and increased emissions.
1. Most Common Causes
- Faulty rocker arm actuator position sensor
- Wiring or connector issues (open, short, corrosion)
- Failed rocker arm actuator solenoid
- Engine control module (ECM) software or hardware problem
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or misfire
- Reduced engine power or hesitation
- Poor fuel economy
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect wiring and connectors for damage or corrosion.
Step 3: Test sensor resistance and voltage with a multimeter.
Step 4: Check actuator solenoid operation and circuit integrity.
Step 5: Perform a rocker arm actuator test using a scan tool.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause engine performance issues and potential damage to the valve train.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on the cause and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.