What Does P1252 Mean?
DTC P1252 indicates a malfunction in the second pressure regulator control solenoid valve circuit. Vehicles with dual-stage or dual-solenoid fuel pressure regulation systems use this second solenoid for fine-tuning fuel rail pressure under varying operating conditions. A circuit fault in this solenoid degrades the system's ability to maintain precise fuel pressure, particularly during transitions between operating modes.
Common Causes
30%
Failed No. 2 pressure regulator solenoid valve (open or shorted coil)
25%
Wiring fault in the solenoid No. 2 control circuit
20%
Corroded or damaged connector at the secondary pressure regulator solenoid
15%
PCM secondary solenoid driver circuit failure
10%
High-resistance ground connection for the solenoid circuit
Diagnostic Steps
1
Disconnect the No. 2 pressure regulator solenoid and measure coil resistance — compare to manufacturer specification and compare to the No. 1 solenoid reading.
2
Check for continuity and shorts to ground or B+ in the solenoid No. 2 control circuit from the PCM to the solenoid connector.
3
Verify the PCM output for solenoid No. 2 by monitoring the command signal with a scan tool and measuring the corresponding voltage or PWM output at the solenoid connector.
4
Monitor fuel rail pressure behavior during steady-state and transient conditions — pressure oscillations or inability to maintain target pressure under specific conditions indicates the secondary regulator circuit is not functioning.
5
Inspect the solenoid and connector for physical damage, heat exposure, or contamination from fuel leaks.
Estimated Repair Cost
$150 - $700
Parts + labor, varies by vehicle and location
DTC P1252 indicates a malfunction in the second pressure regulator control solenoid valve circuit. Vehicles with dual-stage or dual-solenoid fuel pressure regulation systems use this second solenoid for fine-tuning fuel rail pressure under varying operating conditions. A circuit fault in this soleno...
The most common cause of P1252 (Pressure Regulator Control Solenoid Valve No. 2 Circuit Malfunction) is: Failed No. 2 pressure regulator solenoid valve (open or shorted coil)
Typical repair costs for P1252 range from $150 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The primary pressure regulator may compensate for the secondary solenoid failure, but fuel pressure control precision is reduced. This can cause drivability issues including hesitation, surging, and increased emissions. Under high-load conditions, the loss of fine pressure control may cause lean or rich excursions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1252 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Pressure Regulation
Difficulty
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