P2A73: Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit High

What it means

The alternative fuel hydraulic fuel pump select valve 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

The module controls the alternative-fuel hydraulic pump select valve through an electrical circuit and monitors its signal. P2A73 sets when the signal is higher than expected, which may occur if the control wire shorts to battery voltage, the valve coil is open, or connector contact is poor.

Common causes

Most likely first.

1. Control wire shorted to B+
2. Open valve coil
3. Connector pins corroded - high contact resistance

Symptoms

• Check engine light on
• Hard start, no start, or stalling under load
• Power loss especially at high load or rpm
• Possible long cranking time

How to diagnose it

1. Check freeze-frame data and related codes, then note whether the high signal coincided with a starting or pump-selection fault.
2. Inspect the valve connector and harness for corrosion, loose pins, or a control wire contacting a power source.
3. Check connector terminals for poor contact that could disrupt the valve circuit.
4. Test the control wire for a short to battery voltage and test the valve coil for an open circuit according to the wiring diagram.
5. If the circuit and coil test normally, verify module output using the manufacturer's diagnostic procedure.

Common fixes

• Repair a control wire shorted to battery voltage.
• Restore corroded, loose, or damaged connector terminals.
• Replace the select valve if its coil is open.
• Repair a confirmed module-side circuit fault following the manufacturer's procedure.

Can I keep driving?

Avoid high-load driving if the vehicle has hard starting, stalls, or loses power because the select valve may not operate as commanded. Stop if it stalls repeatedly or cannot maintain safe power.