U3003: The battery voltage seen by this unit is out of the normal range
The battery voltage seen by this unit is out of the normal range. It is usually the battery, the alternator or a poor connection.
| Code | U3003 |
|---|---|
| System | Communication network |
| Group | U30xx, Communication network |
| Type | Generic: it means the same on every make |
How to read and clear U3003 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see U3003 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- U3000 The control unit is not working properly
- U3001 The control unit shut down improperly
- U3002 The vehicle identification number is not working properly
- U3004 The accessory power relay is not working properly
- U3005 There is a fault in the retained accessory power function after the car is
- U3006 The control unit input power A is not working properly
- U3007 The control unit input power B is not working properly
What does code U3003 mean?
The battery voltage seen by this unit is out of the normal range. It is usually the battery, the alternator or a poor connection.
How do you clear U3003?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, U3003 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
