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OBD-II Diagnostic Trouble Code
P0D21

Hybrid/EV Battery Charger Input Power Low

P
Powertrain
engine / trans
0
Generic
SAE standard
D
Powertrain subsystem
21
Hybrid/EV Battery Charger Input Power Low
Severity · general guide
Low to moderate
This affects charging rather than driving; the car usually still drives, but range and charging are impaired.
Code type
Generic
System
Powertrain
Quick answer

The vehicle generally still drives on its current charge — the problem is with taking on power — so it is safe to drive, but resolve the charging fault (starting with the outlet and charger) to avoid being left with low range. P0D21 is a plug-in hybrid/EV charging code meaning the onboard charger sees low AC input power — the electricity coming in from the charging station or outlet is lower than expected. It usually shows up as slow charging, interrupted charging or a charge fault, and the first things to check are the charging source and cable.

What P0D21 means

When you plug in a hybrid or electric vehicle, the onboard charger converts AC power from the wall or charging station into DC to fill the high-voltage battery. P0D21 sets when that charger detects the incoming AC input power is too low to charge properly. That can come from the supply side — a weak circuit, a marginal outlet, a fault in the charging station (EVSE) or cable — or from the vehicle's own charging hardware and sensing. Because it is about the power coming in, the practical first step is to rule out the charging source before suspecting the car. Charging components operate at high voltage, so internal charger repairs belong to a qualified HV technician.

Symptoms

  • Vehicle charges slowly, stops charging, or reports a charge fault
  • Charging repeatedly interrupts or fails to start
  • Charge-status light or message indicating a supply or power problem
  • Problem varies with the outlet, circuit or charging station used
  • Full charge takes far longer than normal
  • No stored drivability faults — the issue is specific to charging

Common causes

  • Weak or overloaded household circuit or a marginal outlet
  • Faulty or underpowered charging station (EVSE) or damaged charge cable
  • Loose or corroded charge-port or connector contacts
  • Voltage drop from a long or undersized extension/adapter (where used)
  • Onboard charger fault or its AC input sensing reading low
  • Utility/supply voltage sag at the charging location

Severity & driving advice

Severity: Low to moderate — This affects charging rather than driving; the car usually still drives, but range and charging are impaired.

Can I drive? The vehicle generally still drives on its current charge — the problem is with taking on power — so it is safe to drive, but resolve the charging fault (starting with the outlet and charger) to avoid being left with low range.

Diagnostic approach

  1. Try a different known-good sourceCharge from another outlet or charging station and cable to see whether the fault follows the car or the supply.
  2. Check the outlet and circuitVerify the outlet delivers correct, stable voltage under load and is on an adequately rated circuit without other heavy loads.
  3. Inspect the charge port and cableLook for damaged, dirty or loose contacts at the vehicle charge port and on the connector, and confirm the cable is undamaged.
  4. Read charging dataUse a capable scan tool to view the charger's AC input readings and compare them with the actual measured supply voltage.
  5. Evaluate the onboard chargerIf the supply is confirmed good but the car still reports low input, the onboard charger or its sensing needs qualified HV diagnosis.

Estimated repair costs

Typical US repair costs (parts & labour) for the faults behind P0D21. These are national-average estimates, not a quote— your actual price varies by region, shop labour rate, and your vehicle’s make, model and year. Figures reviewed 2026.

RepairEstimated cost (USD)
Diagnosis (charging system check)$90–$200
Charge cable / EVSE replacement$150–$600
Charge-port / connector repair$150–$500
Onboard charger repair$600–$2,500

FAQ

Is P0D21 the car's fault or the charger's?

Often it is the supply side — a weak outlet, circuit or charging station. Trying a different known-good source first tells you whether the problem follows the car or the charger.

Can I still drive with P0D21?

Yes — the code concerns charging, not driving, so the car runs on whatever charge it has; just address the charging fault so you don't run low on range.

Why does charging work on one outlet but not another?

A marginal or overloaded circuit delivers lower voltage under load, so the charger sees low input on that outlet while a stronger circuit charges normally.

Do I need a dealer to fix P0D21?

Supply-side checks and cables are simple, but if the onboard charger itself is at fault it must be repaired by a technician trained for high-voltage work.