What Does P266A Mean?
The PCM has detected a circuit fault with the rocker arm actuator position sensor on Bank 2 (cylinder bank opposite cylinder 1). This sensor monitors the position of variable valve timing or cylinder deactivation rocker arm mechanisms.
Common Causes
35%
Failed rocker arm actuator position sensor Bank 2
30%
Damaged or corroded sensor connector or wiring
20%
Open or short circuit in sensor signal or ground wires
10%
Low or high voltage supply to position sensor
5%
Mechanical damage to rocker arm actuator affecting sensor mounting
Diagnostic Steps
1
Step 1: Inspect rocker arm position sensor connector for corrosion, damage, or oil contamination
2
Step 2: Measure sensor supply voltage (typically 5V reference) and ground circuit continuity
3
Step 3: Check sensor signal voltage with key on and during engine operation using scan tool data
4
Step 4: Measure sensor resistance according to manufacturer specifications
5
Step 5: Remove valve cover and inspect rocker arm actuator mechanism for mechanical binding or damage
Estimated Repair Cost
$200 - $700
Parts + labor, varies by vehicle and location
The PCM has detected a circuit fault with the rocker arm actuator position sensor on Bank 2 (cylinder bank opposite cylinder 1). This sensor monitors the position of variable valve timing or cylinder deactivation rocker arm mechanisms.
The most common cause of P266A (A Rocker Arm Actuator Position Sensor Circuit Bank 2) is: Failed rocker arm actuator position sensor Bank 2
Typical repair costs for P266A range from $200 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause reduced engine performance, increased fuel consumption, or rough idle. Safe to drive but performance will be limited and fuel economy affected.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P266A to identify the root cause.
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Quick Info
Category
Powertrain
System
Variable Valve Timing / Cylinder Deactivation
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
