Powertrain, generic · Hybrid propulsion

P0B37 High Voltage Service Disconnect Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B37 means the controller sees the service disconnect as open, either because the plug is really removed or because its detection loop is broken. Ford uses the code in the battery energy control module of the 2013-2016 C-Max Energi: bulletins SSM 46108 and TSB 17-0015 describe intermittent stalls or no crank with a Stop Safely Now message and MIL, stored with U3012 and, in another module, the interlock code P0A0A. The cause was an intermittent short to ground in the low-voltage interlock wiring, found by inspecting the harness for chafing. P0B33 to P0B36 cover circuit, performance, low and high faults. For the driver: the car shuts down or will not start.

Likely causes

Low-voltage interlock wiring chafed with intermittent short to ground (Ford C-Max)
Service disconnect plug removed, loose or not locked
Open terminal in the plug base or interlock connector
Battery energy control module fault

Symptoms

  • Intermittent stall or no crank
  • Stop Safely Now message and MIL
  • High-voltage interlock code stored in another module

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–1,500
Time0.5–4 h

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

Parts involved

hv service disconnect switchwiring harnessbms

Related codes

P0B33P0B34P0B35P0B36P0A0A

References: static.nhtsa.gov, patents.google.com, patents.google.com, law.cornell.edu.