Powertrain, generic · Hybrid propulsion

P0BAD Hybrid/EV Battery Voltage Sense W Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0BAD is reserved for a W signal that drops out or jumps for short moments instead of failing outright. No manufacturer documents the code publicly. GM monitors channel W in several programmes, from the 2011 Volt to the eAssist and the 2019 tables, but only through P0BA9 to P0BAC; none of them contains an intermittent test. The slot exists because J2012 gives every sense channel five codes and CARB 1968.2 requires the battery voltage sensors of a hybrid energy storage system to be monitored with fault codes that point to the smallest replaceable part. If a vehicle did store it, the usual suspects would be a crimp or connector that loses contact under vibration or with temperature changes.

Likely causes

Loose or fretting connector pin on lead W
Crimp on lead W opening with temperature changes
Cracked solder joint on the monitoring board input W

Symptoms

  • Warning lamp that comes and goes
  • Occasional short power reduction

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–5,000
Time1–8 h

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

Parts involved

hv battery voltage sense wwiring harnessbms

Related codes

P0BA9P0BAAP0BABP0BACP0BA8P0BB2

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