What Does P255D Mean?
The PCM has detected an abnormally high voltage signal from the secondary PTO speed selector sensor or switch circuit. This suggests a short to voltage, open ground circuit, or sensor malfunction preventing accurate PTO speed detection.
Common Causes
35%
Open or damaged ground circuit at sensor
30%
Faulty PTO speed selector sensor/switch reading high
20%
Signal wire shorted to voltage source or battery power
10%
Corroded sensor connector causing high resistance
5%
PCM internal fault misreading sensor voltage
Diagnostic Steps
1
Step 1: Inspect sensor connector and terminals for corrosion or damage
2
Step 2: Measure voltage at sensor signal wire with key on; should not exceed reference voltage (typically 5V)
3
Step 3: Check ground circuit continuity from sensor to chassis/PCM ground
4
Step 4: Disconnect sensor and measure resistance; compare to specifications
5
Step 5: Check for voltage shorts in wiring harness using voltage drop testing
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
The PCM has detected an abnormally high voltage signal from the secondary PTO speed selector sensor or switch circuit. This suggests a short to voltage, open ground circuit, or sensor malfunction preventing accurate PTO speed detection.
The most common cause of P255D (PTO Speed Selector Sensor/Switch 2 Circuit High) is: Open or damaged ground circuit at sensor
Typical repair costs for P255D range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but PTO system will not function properly. Avoid using PTO attachments until repair is completed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P255D to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Power Take-Off System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
