Code
P1113
DS
P — Powertrain
Fuel pressure regulation
AI status
Completed
Completed
100%
Causes
- Faulty fuel pressure sensor (fuel rail pressure sensor)
- Defective fuel pressure regulator or fuel pressure control valve/solenoid
- Weak or failing fuel pump or lift pump
- Clogged fuel filter or restricted fuel line
- Wiring/connectors short, open, corrosion, or poor ground to sensor or control valve
- ECU/software fault or incorrect calibration
Symptoms
- Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
- Hard starting, especially when hot or under load
- Engine hesitation, loss of power, or poor acceleration
- Rough idle, stalling, or surge
- Reduced fuel economy
- Possible drivability limp mode triggered by ECU
What to check
- Read freeze-frame and live fuel pressure PIDs with a diagnostic scanner; record commanded vs actual rail pressure
- Visually inspect wiring and connectors for the fuel pressure sensor and control solenoid (damage, corrosion, water ingress, poor pins)
- Check fuel pump prime and listen for pump operation during key-on
- Measure fuel rail pressure with a calibrated fuel pressure gauge (or high-pressure gauge for direct injection systems)
- Inspect and, if serviceable, replace fuel filter and check for restrictions
- Check for fuel leaks at rail, hoses, and injectors
Signal parameters
- Fuel pressure sensor reference signal typically 5 V reference and ground; sensor output commonly 0.5–4.5 V (varies by manufacturer)
- Low-pressure (returnless) fuel rail idle target often ~2–4 bar (30–60 psi); high-pressure common‑rail systems run 200–1600 bar depending on engine and load — consult factory data
- Fuel pressure control solenoid often driven by PWM; expected duty cycle varies with engine load (0–100%) and is commanded by ECU
- No-load fuel pump current draw should be within factory spec; excessive draw may indicate pump or restriction
Diagnostic algorithm
- Retrieve and record all DTCs and freeze-frame data. Verify P1113 is current and note conditions (engine temp, rpm, load).
- Monitor live data: commanded fuel pressure, actual fuel pressure, fuel pump status, and related PIDs while running and during key-on. Look for mismatch or lag.
- Visually inspect wiring/connectors to pressure sensor and control solenoid. Repair any damaged wiring or corroded terminals.
- Backprobe sensor: with engine off, verify 5 V reference (or specified reference), ground continuity, and sensor output voltage. With engine running, observe sensor voltage change with throttle.
- Attach an appropriate fuel pressure gauge to the rail (use correct adapter and safety precautions). Compare measured pressure to commanded values at idle, during acceleration, and under load. For high-pressure systems use a rated test tool.
- Test fuel pressure control solenoid: check electrical operation (apply bench 12 V or use diagnostic active test/PWM) and measure response of rail pressure to commanded changes.
- Check fuel pump flow/pressure and inspect/replace fuel filter if suspect. Verify feed and return lines are not restricted and check for leaks.
- If wiring and mechanical components test good but readings are out of range, consider replacing the fuel pressure sensor or control solenoid one at a time and retest.
- If component replacements do not cure the fault, investigate ECU power, grounds, and software; consult manufacturer bulletins and wiring diagrams before replacing ECU.
- Clear codes and perform road test under the original fault conditions to confirm repair.
Likely causes
- Faulty fuel pressure sensor or bad sensor signal (voltage out of range, intermittent)
- Fuel pressure regulator/control solenoid sticking or not responding to ECU commands
- Low fuel pressure due to weak pump or clogged filter
- Damaged wiring or connector between sensor/solenoid and ECU
Fault status
Status
The engine control unit detected improper regulation of fuel pressure. This can be caused by a bad pressure sensor, faulty pressure regulator/solenoid, low pump output, clogged filter, wiring fault, or ECU issue. Perform diagnostic checks to isolate the faulty component; do not assume a single cause without testing.
Repair difficulty: Medium
Diagnostic time: 1.0 - 3.0 hours
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