Powertrain, generic · Hybrid propulsion

P0B7D Hybrid/EV Battery Voltage Sense N Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B7D concerns a channel N value that stays inside its limits yet does not behave like a real cell. GM's 2016 tables show how the same check is tuned per vehicle: the Chevrolet Volt fails when cell N does not move with the average for 7 of 8 seconds, while the Cadillac ELR counts 20 of 40 samples at 200 ms once the average shifts by more than 0.006 V; both are Type A. On the 2012 two-mode hybrids N corresponds to NiMH block 14, and blocks 14 and 15 scaled by twenty must agree with the pack voltage within 70 V, otherwise 160 of 170 samples set a Type B code. The 2019 processor uses its 0.005 V trend test, 35 of 40 samples. Often a battery controller reflash or a board repair is the fix.

Likely causes

Channel N value not tracking the other cells
Outdated battery controller calibration
Block 14 or 15 voltage mismatch on two-mode NiMH packs

Symptoms

  • MIL with hybrid service message
  • Shorter electric range or less assist

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–5,000
Time0.5–6 h

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

Parts involved

hv battery voltage sense nwiring harnessbms

Related codes

P0B7CP0B7EP0B7FP0B80P0B78P0B82

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.