P0D20Battery Charger A Output Voltage Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- 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.
- What you may notice
- Charging stops early or the battery does not reach its target level
- MIL and charging system message
- Likely causes
- LikelyFault in the charger's power stage or voltage control
- PossibleInaccurate output voltage measurement
- RareCharge control software in the hybrid control module
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €0 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.