P2A24: Alternative Fuel Tank Shutoff Valve B Control Circuit Low

P2A24 means the alternative fuel module sees the control line of shutoff valve B sitting too low. TransEco Energy, which converts trucks to CNG, assigns it in the fault table of its AFCM v1.4 to a lead shorted to ground or open, lights the MIL on dedicated and bi-fuel systems alike and does not force a fallback. The same table prints P2A14 in a second column beside it, a number that current code lists give to injection pump metering C. Ford's 2014 Boss 302S code list also includes P2A24, though without the MIL marker it shows for P224E. Chafed wires along the cylinder mounts are a classic cause. P2A25 is the high counterpart, P2A28 the matching fault on valve C.

Symptoms

• Check engine light
• Gas from tank B unavailable, range reduced

Most likely causes

• Control wire of valve B chafed through to ground at a tank bracket
• Open lead, which the TransEco module reports under this code
• Shorted turns in the coil of valve B

What to check, in order

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

1. If you smell gas, shut off the supply, ventilate and do not start the engine
2. With the connector unplugged, check whether the signal wire is making contact with ground.
3. Read the codes with a compatible scanner
4. Check the connectors and wiring of the component indicated
5. Leave any work on the gas circuit to an authorized shop

Good to know

• Repair difficulty: hard
• It affects emissions.

What each character of P2A24 means

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

Frequently asked questions

Can I keep driving with code P2A24?

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 P2A24?

The most common causes are: control wire of valve B chafed through to ground at a tank bracket; open lead, which the TransEco module reports under this code; shorted turns in the coil of valve B.

Related codes

• P2A22Alternative Fuel Tank Shutoff Valve B Control Circuit/Open
• P2A23Alternative Fuel Tank Shutoff Valve B Control Circuit Performance/Stuck Off
• P2A25Alternative Fuel Tank Shutoff Valve B Control Circuit High
• P2A28Alternative Fuel Tank Shutoff Valve C Control Circuit Low
• P224EAlternative Fuel Tank Shutoff Valve A Control Circuit Low

Sources

• transecoenergy.com: DTC List
• performanceparts.ford.com: 2014 BOSS 302S OBDII Codes
• law.cornell.edu: 13 CCR 1968.2

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.