OBD Guide

P2A78

Alternative Fuel Hydraulic Pump Pressure Sensor Circuit High

P2A78 is an OBD-II diagnostic trouble code meaning: Alternative Fuel Hydraulic Pump Pressure Sensor Circuit High. Common causes: malfunction of the hydraulic pump pressure sensor, open or short circuit in the sensor circuit. Estimated repair cost: $28–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • The Check Engine light comes on
  • Reduced engine power
  • Unstable engine operation
  • The car goes into emergency mode
  • Problems with switching to alternative fuels

Causes

  • Malfunction of the hydraulic pump pressure sensor
  • Open or short circuit in the sensor circuit
  • Alternative Fuel Hydraulic Pump Problems
  • Corrosion or poor contact in connectors
  • Engine control unit malfunction

How to Fix

  1. Check connections and sensor wiring harness
  2. Test the pressure sensor with a multimeter
  3. Check alternative fuel hydraulic pump
  4. Replace pressure sensor if necessary
  5. Reset the code and check the system after repair

Related codes

Error P2A78 by Vehicle Brand

FAQ

What does the P2A78 code mean?

P2A78 is an OBD-II diagnostic trouble code that indicates: Alternative Fuel Hydraulic Pump Pressure Sensor Circuit High

What causes a P2A78 error code?

The most common causes of P2A78 include: Malfunction of the hydraulic pump pressure sensor; Open or short circuit in the sensor circuit; Alternative Fuel Hydraulic Pump Problems; Corrosion or poor contact in connectors.

How do I fix a P2A78 diagnostic trouble code?

To fix P2A78: Check connections and sensor wiring harness. Test the pressure sensor with a multimeter. Check alternative fuel hydraulic pump. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2A78?

Yes, but get it checked soon

How much does it cost to fix P2A78?

The estimated repair cost for P2A78 is $28–89. Actual cost depends on your vehicle, location, and labor rates.

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