P0D20 code meaning
Battery Charger A Output Voltage Performance
Powertrain system Generic code P0Dxx codes Check engine light
What P0D20 means
P0D20 concerns the on-board charger in its constant-voltage phase, typically near the end of a charge, when it should hold its high-voltage output at a set value. The code means the measured output voltage strays too far from that target. GM's 2011 to 2013 Chevrolet Volt evaluates this in the HPC2/VICM: a deviation of 15 % or more in constant-voltage mode, counted at 100 ms with system voltage above 9 V (2011) or 10.2 V (2012), sets the code after 30 failures in 50 samples, One Trip Type A, so the MIL comes on at once. Later GM tables no longer list it. CARB requires charger faults that stop or slow charging to be detected. Causes lie mostly inside the charger or its voltage sensing. Charging stops or ends early; driving is unaffected. Too low a voltage is P0D21.
P0D20 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0D20
- Charging stops early or the battery does not reach its target level
- MIL and charging system message
Common causes of P0D20
- Most likelyFault in the charger's power stage or voltage control
- PossibleInaccurate output voltage measurement
- Less likelyCharge control software in the hybrid control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Battery charger aWiring harnessHybrid control module
What each part of P0D20 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 20 | The exact fault in that area. |
What to do next
- Note P0D20 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0D20
What does P0D20 mean?
P0D20 means "Battery Charger A Output Voltage Performance". P0D20 concerns the on-board charger in its constant-voltage phase, typically near the end of a charge, when it should hold its high-voltage output at a set value. It is a generic code, so it means the same on every make.
Is it safe to drive with P0D20?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0D20 fail an emissions test?
P0D20 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P0D20 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0D20 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.