Powertrain, generic · Hybrid propulsion

P0D90 Battery Charger Input Frequency Incorrect

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0D90 is stored when the AC supplied to the on-board charger does not have a believable mains frequency. No official manufacturer document available to the public names the code with a threshold. A Ford patent on charger-to-EVSE detection describes the obvious method: after the pilot signal is present and S2 is closed, the charger measures the interval between successive zero passes of the incoming AC, increments an error counter whenever the result is under 40 Hz or over 70 Hz and stores a code after a set number of errors. The patent notes that the frequency fault need not stop charging, and that a frequency error together with a lost pilot is treated as the higher-ranking loss of AC power. Unstable sources such as small generators or faulty portable EVSEs are the usual trigger; often the driver notices nothing at all.

Likely causes

Charging from a source with unstable frequency (small generator, inverter)
Faulty portable charging unit or wall box
Fault in the charger's frequency measurement

Symptoms

  • Often no noticeable effect apart from the stored code
  • Charging interrupted at certain supply points

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–1,500
Time0.2–2 h

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

Parts involved

battery charger input

Related codes

P0D80P0D81P0D27P0D28

References: patents.google.com, law.cornell.edu.