Low fuel pressure from a weak pump, blocked fuel filter or restricted fuel supply; Dirty, sticking or worn injectors delivering less fuel than commanded; Faulty fuel rail pressure sensor or regulator giving wrong pressure data or poor pressure control; Wiring or connector fault in the injector circuit or fuel pump supply, such as high resistance or corrosion; Incorrect coolant temperature reading leading to the wrong cold start fuel strategy; Air leak or faulty air mass reading that upsets fuelling calculations; Contaminated or poor quality fuel.

P027E

Cold Start Fuel Injection Quantity A Lower Than Expected.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
7E: FaultThe specific fault in that area

What it means

P027E means the engine control unit judged that the fuel quantity delivered during a cold start was lower than the quantity it commanded or expected. It sets the code by comparing the commanded fuel against what it can infer from fuel pressure, injector feedback, engine speed or mixture feedback. The exact method and the meaning of 'A' (a bank, injector group or circuit) depend on the engine and model.

Symptoms

Long cranking or hard starting when cold
Rough or unstable idle after a cold start
Hesitation or poor throttle response until warmed up
Engine misfire or stumbling on cold start
Engine warning light on
Possible reduced power or limp mode on some models

Possible causes

Low fuel pressure from a weak pump, blocked fuel filter or restricted fuel supplylikely
Dirty, sticking or worn injectors delivering less fuel than commandedlikely
Faulty fuel rail pressure sensor or regulator giving wrong pressure data or poor pressure controlpossible
Wiring or connector fault in the injector circuit or fuel pump supply, such as high resistance or corrosionpossible
Incorrect coolant temperature reading leading to the wrong cold start fuel strategypossible
Air leak or faulty air mass reading that upsets fuelling calculationspossible
Contaminated or poor quality fuelrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting coolant temperature, engine speed and fuel pressure at the time the code set
Check for related codes such as fuel pressure, misfire, lean mixture or injector circuit faults, and deal with those first
Inspect the injector and fuel pump wiring, connectors and relevant fuses for damage, corrosion or heat damage
Compare live coolant temperature and intake air temperature with actual conditions on a cold engine to check the sensors are plausible
Monitor fuel rail pressure during a cold start against the manufacturer specification for your engine
Check fuel pressure and volume delivery, and the condition and service history of the fuel filter where one is fitted
Check for air leaks and inspect the air intake, and review fuel trim values on a cold and warm engine
Test or balance-check the injectors using the procedure for your specific engine, since the method varies by model

How to fix

Replace a weak fuel pump or a restricted fuel filter, and correct any supply restriction
Clean or replace faulty injectors as the test results indicate
Replace a faulty fuel pressure sensor or regulator, or repair the pressure control fault
Repair damaged wiring or connectors in the injector or pump circuits
Replace a faulty coolant temperature sensor, or repair air leaks and faulty air flow measurement
Drain and replace contaminated fuel, then clear the code and confirm it does not return on a cold start

Can I keep driving?

Medium severity

The car can usually be driven short distances, but fix it soon because poor fuelling can cause hard starting, misfires and extra strain on the engine and catalyst. If it stalls, runs very roughly or goes into limp mode, stop driving and get it checked.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.