Powertrain, generic · Hybrid propulsion

P0B88 Hybrid/EV Battery Voltage Sense P Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

A too-low value on sense P, the sixteenth channel, is what P0B88 records. GM's BAS Plus mild hybrid sets it at a cell sense line below 1.4 V for 7 of 10 samples, sampled every 200 ms and only with the 12 V battery above 8.8 V; it rates the fault Type B. The full lithium-ion systems in GM's 2016 and 2019 tables react at 0.2 V or less after 1.4 s in a 2 s window and set it as Type A. In the 2012 two-mode NiMH pack, P is block 16; blocks 16 and 17 must both stay below 2 V for 15 of 20 samples. A collapsed reading usually traces back to a short between the P lead and a lower potential, sometimes to a defective input; it is rarely the cell itself. The open-circuit condition is reported separately with P0B86.

Likely causes

Lead P shorted to a lower potential or chassis

Defective input in the battery interface module

Weak cell or NiMH block 16

Symptoms

MIL and reduced propulsion power
Auto stop no longer active

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€100–6,000

Time1–8 h

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

Parts involved

hv battery voltage sense pwiring harnessbms

Related codes

P0B86 P0B87 P0B89 P0B8A P0B83 P0B8D

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