P027E: Cold Start Fuel Injection Quantity A Lower Than Expected

What it means

During cold start the injection quantity A is below the commanded amount. Hard starting in cold conditions.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

During cold starting, the control module estimates and monitors injection quantity A as the engine warms. This code sets when quantity A is lower than expected, which can leave the engine short of fuel during the cold-start phase; it does not by itself identify a particular cylinder or injector.

Common causes

Most likely first.

1. Injector restricted or worn
2. Low fuel pressure
3. Fuel supply restriction
4. Injector wiring or control fault

Symptoms

• Check-engine light
• Hard starting when cold
• Rough running after startup
• Reduced power

How to diagnose it

1. Record freeze-frame data from a cold start and compare commanded and reported injection quantity A with live fuel-pressure and temperature data.
2. Inspect the fuel supply and injector wiring or connectors for visible damage, loose connections, or restrictions.
3. Check fuel pressure and delivery during the conditions that trigger the code, using the manufacturer's specification.
4. Test injector operation and electrical control for quantity A using vehicle-specific service information.
5. If fuel delivery and injector control pass, investigate related sensors or control inputs that affect cold-start fueling.

Common fixes

• Repair loose or damaged injector wiring or connectors.
• Replace a restricted fuel filter or repair a confirmed supply restriction.
• Restore fuel pressure if testing identifies a supply or pressure fault.
• Clean or replace a confirmed restricted or worn injector.

Can I keep driving?

You may be able to drive if the engine starts and runs smoothly, but avoid relying on it for cold starts until diagnosed. A lean or rough cold start can cause stalling and increased emissions.