Powertrain, generic · Hybrid propulsion

P0A86 14 Volt Power Module Current Sensor A Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The 14 volt power module is the DC/DC converter that feeds the 12 V network of a hybrid or electric vehicle from the high-voltage battery; GM calls it the Accessory Power Module (APM). Current sensor A measures the current flowing through this converter. P0A86 is the general circuit code for that sensor, used when the controller recognises a fault in the sensor circuit without classifying it as low, high, implausible or intermittent (P0A87 to P0A8A). No manufacturer documents this code publicly; GM's published tables for the same APM input sensor use only the low/high codes P0A88 and P0A89. With an untrustworthy current reading the hybrid controller may limit or switch off the converter, so the 12 V battery can run down over time.

Likely causes

Current sensor inside the 14 V power module faulty (usually not replaceable separately)
Damaged wiring or corroded connector between module and hybrid controller
Software fault in the module or hybrid controller

Symptoms

  • Hybrid or charging system warning lamp on
  • 12 V battery discharges, low-voltage warnings
  • Possibly no other noticeable change in driving

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–1,800
Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

pm14v current sensor awiring harnessdcdc converter

Related codes

P0A87P0A88P0A89P0A8AP0CC5

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com.