Powertrain, generic · Hybrid propulsion

P0AF7 14 Volt Power Module Internal Temperature Too High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The 14 V power module is the DC/DC converter that feeds the 12 V network from the high-voltage battery in hybrids and EVs. P0AF7 reports that its internal temperature has exceeded the protection limit, a real overheat rather than a sensor circuit fault. No manufacturer documents this exact code publicly. GM's 2013 eAssist table shows how the same module is watched: its Accessory Power Module has two temperature sensors with their own circuit codes, and the separate code P0C32 compares sensor 1 with a thermal model and fails if they differ by more than 15 °C. CARB requires monitoring of hybrid components. Common causes are a blocked cooling path, a weak coolant pump or fan, or a constantly high 12 V load. The module then derates its output, so the 12 V battery may run down.

Likely causes

Restricted cooling, weak coolant pump or failed cooling fan
Sustained high 12 V load or weak 12 V battery
Internal fault of the DC/DC converter

Symptoms

  • Warning lamp or 12 V charging warning
  • Low 12 V voltage, flickering lights
  • Comfort consumers switched off

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–2,000
Time0.5–5 h

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

Parts involved

pm14v moduledcdc converter

Related codes

P0A8FP0A8DP0A8EP0A87P0C32

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