Powertrain, generic · Hybrid propulsion

P0A8E 14 Volt Power Module System Voltage High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0A8E signals too high a voltage at the 14 V power module, the DC/DC converter supplying the 12 V side. In GM's 2013 eAssist tables it is the circuit-high check of the APM low-voltage sensor: a reading above 20 V for 1.5 s within a 2 s window, with ignition voltage 9 to 32 V, sets the code, and it passes below 19.5 V. GM rates it Type B, so the MIL comes on after two failing trips. Since the network should sit around 14 V, a reading over 20 V usually means a sense line shorted to a higher potential or a faulty sensor; a genuinely over-regulating converter would also threaten bulbs and modules. P0A8D is the low counterpart, P0A8F compares the sensor with the ignition voltage.

Likely causes

Voltage sense line shorted to a higher potential
Voltage sensor inside the power module failed
Converter regulating its output too high

Symptoms

  • MIL and charging/hybrid warning
  • Very bright lights or failing bulbs if overvoltage is real
  • Converter may be shut down

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–1,800
Time1–4 h

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

Parts involved

pm14v moduledcdc converter

Related codes

P0A8BP0A8CP0A8DP0A8FP0563

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