OBD-II code · Powertrain (generic, extended)
P2A77 Alternative Fuel Hydraulic Pump Pressure Sensor Circuit Low
Voltage on the alternative fuel hydraulic pump pressure sensor signal line is below the expected window. Wire shorted to ground or sensor short.
Is it safe to drive with P2A77?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to ground
- PossibleInternal sensor short
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- Parts involved
- Alt Fuel Hyd Pump Pressure Sensor, Wiring Harness, Afcm
Related codes
- P2A74Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit Intermittent/Erratic
- P2A75Alternative Fuel Hydraulic Pump Pressure Sensor Circuit
- P2A76Alternative Fuel Hydraulic Pump Pressure Sensor Range/Performance
- P2A78Alternative Fuel Hydraulic Pump Pressure Sensor Circuit High
- P2A79Alternative Fuel Hydraulic Pump Pressure Sensor Circuit Intermittent/Erratic
- P2A7AAlternative Fuel Hydraulic Pressure Sensor Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.