P240E

Code

Generic P — Powertrain

Alternative Fuel High Pressure System Leak

Brand: Generic

Type: P — Powertrain

Views: UK: 19 EN: 28 RU: 17

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Read and record all stored and pending DTCs and freeze-frame data
Inspect for related codes for pressure sensor, pump, or injectors
Visually inspect high-pressure lines, fittings, and components for damage or loose connections
Check wiring and connectors at the high-pressure sensor and pump for corrosion, breaks, or poor contact
Perform a pressure hold/decay test on the pressurized circuit per manufacturer procedure
Use approved gas leak detection methods (electronic detector, soapy water, or manufacturer-specified spray) while system is pressurized

High-pressure sensor output should change consistently with commanded pump/engine load; typically a 0–5 V or 0–100% signal depending on sensor type
System pressure should reach and hold within the manufacturer-specified high-pressure range under static conditions
Pressure decay rate should be minimal during a specified hold period; an excessive drop indicates a leak
Sensor circuit voltage/ground continuity and reference voltage (often 5 V) should be stable
Injector or valve actuator signals may be PWM or switched; their duty cycle/voltage should follow PCM commands

Safety first: follow manufacturer safety procedures for high-pressure alternative fuel systems. Relieve system pressure only with approved tools and trained personnel.
Retrieve all codes and live data. Note freeze-frame conditions (engine temp, RPM, commanded pressure).
Visually inspect the high-pressure system for obvious damage, loose fittings, corrosion, or repairs.
With the system pressurized (follow safe procedures), perform a leak detection scan using an approved gas detector or soapy solution at joints, fittings, valves, injectors and pump.
Perform a pressure hold/decay test at the service port or fuel rail per manufacturer procedure. Record initial pressure and decay over specified time.
Monitor high-pressure sensor output with a scan tool while commanding the pump and under various loads. Compare readings to expected behavior.
Check wiring and connector integrity: backprobe sensor harness for reference voltage, signal, and ground continuity. Wiggle test for intermittent faults.
If a leak source is found (fitting, hose, injector), secure/replace the failed component with manufacturer-specified parts and torque values. Replace seals/O-rings as required.
If sensor readings are out of range but no physical leak is found, bench-test or replace the pressure sensor and recheck circuit operation.
After repairs, perform pressure and leak tests again, clear codes, and perform a road/operation test to confirm repair. Re-scan for codes and verify no reoccurrence.