P00C6: Fuel Rail Pressure Too Low - Engine Cranking Bank 1

What it means

During engine cranking on bank 1, fuel rail pressure does not reach the level needed for start. Hard or no-start condition.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The high-pressure fuel system must build enough rail pressure for the engine to start. During cranking, the control module monitors bank 1 fuel rail pressure and sets P00C6 when it remains below the level needed for starting.

Common causes

Most likely first.

1. HP pump worn
2. Fuel filter clogged

Symptoms

• Check engine light on
• Long cranking or hard starting
• Engine may crank without starting
• Possible stalling shortly after starting

How to diagnose it

1. Record freeze-frame data and compare bank 1 rail pressure during cranking with the manufacturer's starting specification.
2. Check fuel level and inspect for leaks or obvious damage around the fuel supply and high-pressure components.
3. Check the fuel filter for restriction and confirm that the low-pressure supply to the high-pressure pump meets the manufacturer's specification.
4. Inspect the bank 1 rail-pressure sensor connector and wiring for loose pins, corrosion or damage before judging the pressure reading.
5. Test the high-pressure pump and pressure-control components against the manufacturer's specification.

Common fixes

• Replace a clogged fuel filter.
• Repair a confirmed fuel supply leak or restriction.
• Repair damaged wiring or a poor connection at the bank 1 rail-pressure sensor.
• Replace a faulty rail-pressure sensor only after verifying its signal and circuit.
• Repair or replace a worn high-pressure pump if testing confirms it cannot build cranking pressure.

Can I keep driving?

If the engine starts and runs normally, limit driving and avoid situations where stalling would be dangerous; it may become hard to restart or stall. If it will not start, cranks unusually long or stalls, do not keep cranking repeatedly.