P2A2F: Alternative Fuel Tank Shutoff Valve E Control Circuit Performance/Stuck Off

P2A2F signals that valve E was energized but the system did not see the expected gas flow from that cylinder. No manufacturer publishes this code or its test conditions; CARB only requires output components to be checked for a proper reaction to commands. New Flyer's bulletin explains that its tank solenoids switch on while the starter spins the engine to about 400 rpm. A weak battery or a voltage dip during cranking can therefore leave a coil unable to lift its armature, which looks exactly like a valve that hangs shut. GM's bi-fuel Impala regulates gas to 468 to 896 kPa, a useful reference when checking the low-pressure side. Contamination and a closed manual valve remain obvious mechanical causes.

High severity. Can I keep driving?If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.

Symptoms

Check engine light
Cylinder E does not empty
Fault appears mainly after cold or weak-battery starts

Most likely causes

Voltage drop during cranking, coil cannot lift the armature
Contaminated or sticking valve E
Manual valve on cylinder E closed

What to check, in order

Start with the simplest. You can tick off each step.

If you smell gas, shut off the supply, ventilate and do not start the engine
Compare the reading with other engine data while varying the engine speed.
Read the codes with a compatible scanner
Check the connectors and wiring of the component indicated
Leave any work on the gas circuit to an authorized shop

Good to know

Repair difficulty: hard
It affects emissions.

What each character of P2A2F means

P: Powertrain: engine and transmission
2: Generic code: same on every make
A: Hybrid or air and fuel
2F: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2A2F?

If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.

What causes code P2A2F?

The most common causes are: voltage drop during cranking, coil cannot lift the armature; contaminated or sticking valve E; manual valve on cylinder E closed.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.