P0D25: Battery Charger System Precharge Time Too Short

P0D25 is about the precharge of the charger's high-voltage bus, the short phase before the charging contactors close in which the bus capacitance is brought up to battery voltage through a limiting path. The code means this voltage arrived sooner than physically plausible. No manufacturer documents P0D25 publicly. GM describes the counterpart test for the charger bus under P0D26, with a window of 5 % around pack voltage, and the same principle for the main battery under P0C77, where the 2011 Volt flags a rise above 95 % within 50 ms. A rise that quick suggests a bypassed precharge resistor, a contactor that is welded or closes early, missing bus capacitance or a voltage sensor reporting wrong values. CARB requires charger faults that affect charging to be detected. Charging is normally refused.

Symptoms

• Charging refused at the start of a session
• Charging system warning

Most likely causes

• Precharge resistor bypassed or shorted
• Charging contactor welded or closing too early
• Bus or pack voltage sensor reporting wrong values
• Bus capacitance much lower than expected

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Make sure the battery cooling air intake is clean
3. Check the 12 V auxiliary battery, which can also trigger warnings
4. Leave any high-voltage measurements to a specialized repair shop

What each character of P0D25 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• D: Subsystem depends on the code range
• 25: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0D25?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0D25?

The most common causes are: precharge resistor bypassed or shorted; charging contactor welded or closing too early; bus or pack voltage sensor reporting wrong values.

Related codes

• P0D26Battery Charger System Precharge Time Too Long
• P0C77Hybrid/EV Battery System Precharge Time Too Short
• P0D23Battery Charger A Output Shorted

Sources

• gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
• gsi.ext.gm.com: 12OBDG01A HYBRID Diagnostics
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.