P016E

What it means

P016E is a generic powertrain code meaning the closed loop fuel pressure control has reached its limit while the fuel pressure is too high. The engine control unit compares actual rail pressure with the target and is commanding the regulator or pump to its limit to reduce pressure, but it cannot bring the pressure down. The exact system (high pressure direct injection, common rail or other) and the strategy used depend on the vehicle and engine.

Symptoms

• Malfunction indicator lamp on
• Rough running or hesitation, especially under load
• Hard starting or long cranking
• Reduced power or limp mode
• Surging or unstable idle
• Smell of fuel or visible fuel leak in some cases

Possible causes

• Faulty fuel pressure regulator or pressure control valve sticking closed or not releasing pressurelikely
• Faulty fuel rail pressure sensor giving a false low or inaccurate reading, so the control unit over-correctslikely
• Wiring or connector fault on the regulator, pump control or pressure sensor circuitpossible
• Restricted or blocked fuel return line or pressure relief path (where fitted)possible
• Faulty high pressure fuel pump or pump control (metering) valve over-deliveringpossible
• Injector fault affecting rail pressure behaviour, such as leaking or sticking injectorsrare
• Outdated or faulty engine control unit software calibration, where the manufacturer has issued a known updaterare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting rail pressure, engine speed, load and temperature when the code set
2. Check for related fuel pressure, rail pressure sensor or regulator codes and look for any technical service bulletins for the model and engine
3. Inspect the wiring, connectors and earths for the regulator, pump control valve and pressure sensor for damage, corrosion or water ingress
4. Inspect the fuel system for leaks and check the return line and any pressure relief path for kinks or blockage
5. Compare live actual rail pressure with the target at idle, under load and on key-on, and check the sensor reading against a known good reference such as a mechanical gauge where the system allows
6. Command the regulator or pressure control valve using a bidirectional test and check it responds and the pressure changes as expected
7. Check the regulator and sensor electrical signals and supply voltage against the manufacturer's specification
8. Check fuel quality and condition, as contamination can cause valves to stick

How to fix

• Replace the fuel pressure regulator or pressure control valve if it is stuck or faulty
• Replace the rail pressure sensor if its reading is inaccurate
• Repair damaged wiring, connectors or earths in the affected circuits
• Clear any blockage or replace damaged return lines
• Replace the high pressure pump or metering valve if it is over-delivering, following the manufacturer's procedure
• Apply an engine control unit software update only if one is published to address this fault

Can I keep driving?

Nearby codes

• P016DGenericExcessive Time To Enter Closed Loop Fuel Pressure Control
• P016FGenericClosed Loop Fuel Pressure Control At Limit - Pressure Too Low