01 Private Investigators Say Car Thieves Always Do This One Ex… • 02 How Long Should You Wait Before Changing Your Car’s Oil Aft… • 03 P0106: Manifold Absolute Pressure (MAP) System Performance • 04 Fix This First If Your Car Won’t Start (Before Calling a Me… • 05 What Determines Horsepower in a Car, the Engine or ECU? • 06 B0022, B0024, and B0026: Left Front or Driver Frontal Deplo… • 07 What Do Pilots Say When Crashing? The Truth Behind the Words • 08 Car Engine Overheating: Causes, Troubleshooting, Solutions,… • 09 Understanding Why Brake Calipers Are Sticking When Hot • 10 What Happens When a Pilot Misses the Landing on US Aircraft… •

DTC codes / P0Axx · Hybrid propulsion / P0A87

P0A8714 Volt Power Module Current Sensor A Circuit Range/Performance

P0A87 indicates that the 14-volt power module has detected an out-of-range or performance fault in the current sensor circuit for phase A, which is the current path for one of the module's internal phases. The module compares the current sensor's signal against expected values under specific operating conditions and sets this code when the signal is implausible, erratic, or outside the normal range.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyProfessional
AreaHybrid propulsion

Symptoms you may notice

  • Illumination of the check engine light or service vehicle soon message, often with no other noticeable symptoms
  • Reduced or disabled 14-volt accessory power output, affecting interior lighting, audio, or charging ports
  • Intermittent electrical glitches such as flickering lights or accessories cutting out momentarily
  • The vehicle may enter a reduced-power or failsafe mode that limits electrical load
  • A stored history of related communication or voltage codes in other modules

Common causes, most likely first

  1. Faulty current sensor internal to the 14-volt power module
  2. Damaged or corroded wiring or connector terminals in the current sensor circuit
  3. High resistance or open circuit in the sensor ground or signal return path
  4. Electrical interference or a poor ground connection affecting the module's reference voltage
  5. Internal failure of the 14-volt power module's control circuitry
  6. Low or unstable 12-volt supply voltage to the power module
  7. Aftermarket accessories improperly wired into the 14-volt system causing abnormal current draw

How to diagnose and fix it

  1. Inspect the 14-volt power module connectors and harness for corrosion, loose pins, or chafed wires
  2. Measure the 12-volt supply and ground at the power module to confirm stable power and ground
  3. Check the current sensor circuit wiring for continuity and shorts to ground or power
  4. Compare live current sensor data with a known-good value or expected range using a scan tool
  5. Perform a voltage drop test on the sensor ground and signal circuits under load
  6. If wiring and supply are good, replace the 14-volt power module and clear the code
  7. Verify the repair by test-driving and confirming the code does not return

Why the 14-volt module sets a current code

  • The current sensor is often integrated inside the 14-volt power module and cannot be replaced separately, so a sensor fault usually means module replacement.
  • A weak or failing 12-volt battery can cause the module to log this code because the current sensor's reference voltage becomes unstable during cranking.
  • Aftermarket electrical accessories tapped into the 14-volt output can create current spikes that the sensor interprets as a performance fault, even when the module is healthy.
  • The code can be set by a poor ground connection at the module even if all sensor wiring tests good, so always perform a voltage drop test on the ground circuit.
  • Some vehicles use the 14-volt power module to stabilize voltage for sensitive electronics, and a failing module may cause intermittent faults in other modules without setting their own codes.

Can I keep driving with P0A87?

You can generally drive the vehicle with this code, but avoid relying on the 14-volt accessory system for critical devices and do not ignore repeated electrical glitches. If the vehicle enters a reduced-power mode or accessories fail completely, have it inspected promptly.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage