P0E33 code meaning
DC/DC Converter Voltage Sensor A Low
Powertrain system Generic code P0Exx codes Check engine light
What P0E33 means
P0E33 means the controller reads an implausibly low value from voltage sensor A of a DC/DC converter, typically because the signal wire is shorted to ground. GM documents it in its 2025 engine control tables (25OBDG03A) for a converter that keeps the 12 V network stable while the engine restarts automatically: the raw voltage value 1 must drop below 1 V, and 320 failing samples out of 400 taken every 12.5 ms, about four seconds, are needed. The test runs with at least 6.6 V battery voltage in run/crank or accessory mode. GM rates it Type B, so the MIL comes on after two trips. P0E34 is the opposite case on the same sensor, P0E38 the matching fault on sensor B. Start-stop and the 12 V support can be limited.
P0E33 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0E33
- MIL on after two trips (GM)
- Auto stop/start no longer available
- Possible 12 V voltage dips during engine restarts
Common causes of P0E33
- Most likelySensor signal wire chafed through to ground
- PossibleVoltage measurement inside the converter failed
- Less likelyMoisture in the converter connector bridging to ground
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Dcdc voltage sensor aWiring harnessDcdc converter
What each part of P0E33 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 33 | The exact fault in that area. |
What to do next
- Note P0E33 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 P0E33
What does P0E33 mean?
P0E33 means "DC/DC Converter Voltage Sensor A Low". P0E33 means the controller reads an implausibly low value from voltage sensor A of a DC/DC converter, typically because the signal wire is shorted to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P0E33?
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 P0E33 fail an emissions test?
Yes, it can. P0E33 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0E33 to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0E33 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.