What it means
The alternative fuel tank select valve A control circuit signal is higher than expected.
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
Alternative fuel tank select valve A is controlled through an electrical circuit that operates the valve for tank selection. The control module sets P2A94 when it detects a higher-than-expected signal in valve A's circuit, which can occur if the wire is shorted to battery voltage, the coil is open, or a connection has high resistance.
Common causes
Most likely first.
- Control wire shorted to B+
- Open valve coil
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine or alternative-fuel system warning light, if equipped
- Difficulty switching fuel tanks
- Loss of power or stalling
How to diagnose it
- Record freeze-frame data and check live data to confirm the fault is associated with valve A's control command.
- Inspect valve A's connector for corrosion, loose terminals, or damaged wiring that could interrupt the circuit.
- Check the valve A control wire for contact with a power feed or other chafed insulation that could short it to battery voltage.
- With the circuit isolated as specified by the manufacturer, test valve A's coil and wiring for an open.
- If the cause remains unclear, compare circuit readings at the valve and module connectors with the wiring diagram and manufacturer's specification.
Common fixes
- Clean or replace corroded or loose terminals at valve A's connector.
- Repair the control wire if it is shorted to battery voltage.
- Repair an open in valve A's coil wiring or harness.
- Replace valve A if its coil is open and the control wiring is intact.
Can I keep driving?
Avoid relying on a tank change while valve A's circuit fault is active, and stop safely if the engine loses power or stalls. An incorrectly high circuit signal can prevent reliable fuel selection.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.