Powertrain, generic (extended)

P2E37 Battery Charger B Enable Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2E37 is stored when the enable line of charger B carries more voltage than its commanded state allows, typically because it touches a powered wire or the driver in the commanding module is stuck on. No manufacturer documents P2E37 publicly. The effect differs from P2E36: on an active-high wake line the charger is told to stay awake although no charging is planned. Lear's patent on a wake-by-pilot circuit points out why that hurts, since the charger is meant to sleep together with the whole car to keep the 12 V battery healthy, so a stuck enable can drain it overnight. The control unit may also lose the ability to switch charger B off by hardware. GM's 2016 Volt tables list only the general A-side enable fault P0E61. Low is P2E36, charger A high P0E63.

Likely causes

Enable wire shorted to a 12 V feed
Enable driver in the commanding module stuck on
Internal leakage in the charger B input circuit

Symptoms

  • 12 V battery discharged after standing
  • Charger B fan or pump runs with nothing plugged in
  • Charging via charger B disabled

Repair estimate

DifficultyHardWorkshop job
Parts and labour€60–2,500
Time0.5–4 h

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

Parts involved

on board chargerwiring harness

Related codes

P2E35P2E36P2E38P0E63

References: law.cornell.edu, image-ppubs.uspto.gov, gsi.ext.gm.com.