Powertrain, generic · Hybrid propulsion

P0B5F Hybrid/EV Battery Voltage Sense H Circuit Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

With P0B5F the channel H wiring is intact, but the value it delivers does not fit the rest of the battery. GM runs two quite different plausibility tests. On the 2012 two-mode hybrids (Tahoe, Yukon, Escalade, Silverado, Sierra) channel H is nickel-metal hydride block 8 of 20; the battery pack control module multiplies blocks 8 and 9 by twenty and fails the test when both differ from the measured pack voltage by more than 70 V in 160 of 170 samples, Type B, two trips, with active pack voltage codes P0ABB to P0ABD blocking it. Lithium-ion systems in the 2019 tables look for a frozen reading instead: if H stays put while the average cell voltage trends, 35 of 40 samples set the code, Type A.

Likely causes

Block or cell voltage input for channel H drifting away from the true value

Measuring chip input stuck at a constant value

Faulty pack voltage reference distorting the comparison

Symptoms

Hybrid system warning with MIL
Reduced electric assist or regeneration
Inaccurate state-of-charge display

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€100–5,000

Time1–8 h

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

Parts involved

hv battery voltage sense hwiring harnessbms

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