Powertrain, generic · Hybrid propulsion

P0B52 Hybrid/EV Battery Voltage Sense E Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The threshold behind P0B52 is chosen so that only a measurement error can reach it. A lithium-ion cell is fully charged at roughly 4.2 V, yet GM's battery energy control module waits for 4.8 V or more on channel E, for 1.4 s within 2 s, before storing the code as Type A, one trip. On the nickel-metal hydride packs of the 2012 two-mode trucks and SUVs the corresponding limit is 23 V for block 5, confirmed in 15 of 20 samples and stored as Type B. Since a false high reading could make the controller stop charging early or misjudge balancing, power and charging are restricted. Real overvoltage of a cell is reported by its own cell voltage codes.

Likely causes

Channel E sense line contacting a higher cell tap
Faulty measuring input or reference in the monitoring module

Symptoms

  • Charging stops early or is refused
  • MIL and reduced battery power
  • Shorter electric range

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€50–5,000
Time0.3–6 h

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

Parts involved

hv battery voltage sense ewiring harnessbms

Related codes

P0B4FP0B50P0B51P0B53P0B4DP0B57

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