Powertrain, generic (extended)

P2BEB Hybrid/EV Battery Precharge Contactor Control Circuit B High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2BEB reports too much voltage on control circuit B of the precharge function while it should be off, usually a short to 12 V or a driver that does not switch off. The risk is a second precharge path closing on its own; the resistor can overheat if it stays in circuit. No manufacturer documents P2BEB publicly. For contactor A, GM's 2016 table (P0AE7) fails the off-state output between 5.27 and 19.7 V, 40 of 50 samples at 12.5 ms, Type B, two trips; in 2019 GM folds this case into P0AE4, set when the off-state output exceeds battery voltage minus 0.4 V. A coil stuck energised may later show up as a contactor that stays closed. CARB requires circuit monitoring of hybrid outputs. Low and open are P2BEA and P2BE8.

Likely causes

Coil feed shorted to 12 V
Driver stage stuck on in the battery controller
Damaged insulation between adjacent wires in the harness

Symptoms

  • MIL and hybrid or EV warning on
  • High-voltage system blocked as a precaution

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time1–5 h

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

Parts involved

hv battery precharge contactor bwiring harnessbms

Related codes

P2BEAP2BE8P2BE9P0AE7P0AE2

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