Powertrain, generic (extended)

P2D77 Battery Charger Control Module B Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2D77 says the control electronics of charger B, a second on-board charger or charger stage, do not work as intended; faults of its processor are filed separately under P2D78. No manufacturer documents P2D77 publicly. The A-side twin P0D67 shows what such a check covers: Ford's 2014 hybrid OBD summary flags it during an active charge for internal faults that prevent charging, such as overvoltage in the low- or high-voltage section, a failed PFC stage or a broken high-voltage current sensor. On the 2022 Outlander PHEV, Mitsubishi watches the charger's internal 3.3, 6 and 12 V rails for 1 s and then stops charging. That a charger B exists is shown by Toyota's 6.6 kW RAV4 Prime charger, whose B stage has its own codes. Plug-in charging fails; driving continues.

Likely causes

Internal power or control stage of charger B failed (unit replacement)
Internal low-voltage supply rail of charger B out of tolerance
Weak 12 V supply or poor ground at the charger
Charger software fault, cured by an update where one exists

Symptoms

  • AC charging does not start or stops after a short time
  • Charging fault message or warning in the instrument cluster
  • Charging possible only at reduced power, if the other charger path still works

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–3,500
Time1–5 h

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

Parts involved

battery charger cm bon board charger

Related codes

P2D78P0D67P0E89P2D83

References: law.cornell.edu, fordservicecontent.com, mitsubishitechinfo.com, static.nhtsa.gov.