OBD2 · Network
U03xx codes: software incompatibility between modules
32 codes in this range, all generic — the same meaning on every make. Codes set when modules on the network run software versions that don’t match — almost always after a module was replaced or reprogrammed.
What usually causes codes in this area
- A replacement module that wasn’t programmed to the car
- An interrupted or incomplete software update
- A used module taken from another vehicle
Can you keep driving?
Usually drivable, though the functions involved may be limited. The fix is programming with dealer-level tools, not a new part.
All U03xx codes
| Code | Meaning |
|---|---|
| U0300 | Internal Control Module Software Incompatibility |
| U0301 | Software Incompatibility With ECM/PCM "A" |
| U0302 | Software Incompatibility With Transmission Control Module |
| U0303 | Software Incompatibility With Transfer Case Control Module |
| U0304 | Software Incompatibility With Gear Shift Control Module |
| U0305 | Software Incompatibility With Cruise Control Module |
| U0306 | Software Incompatibility With Fuel Injector Control Module |
| U0307 | Software Incompatibility With Glow Plug Control Module |
| U0308 | Software Incompatibility With Throttle Actuator Control Module |
| U0309 | Software Incompatibility With Alternative Fuel Control Module |
| U0310 | Software Incompatibility With Fuel Pump Control Module |
| U0311 | Software Incompatibility With Drive Motor Control Module |
| U0312 | Software Incompatibility With Battery Energy Control Module "A" |
| U0313 | Software Incompatibility With Battery Energy Control Module "B" |
| U0314 | Software Incompatibility With Four-Wheel Drive Clutch Control Module |
| U0315 | Software Incompatibility With Anti-Lock Brake System Control Module |
| U0316 | Software Incompatibility With Vehicle Dynamics Control Module |
| U0317 | Software Incompatibility With Park Brake Control Module |
| U0318 | Software Incompatibility With Brake System Control Module |
| U0319 | Software Incompatibility With Steering Effort Control Module |
| U0320 | Software Incompatibility With Power Steering Control Module |
| U0321 | Software Incompatibility With Ride Level Control Module |
| U0322 | Software Incompatibility With Body Control Module |
| U0323 | Software Incompatibility With Instrument Panel Control Module |
| U0324 | Software Incompatibility With HVAC Control Module |
| U0325 | Software Incompatibility With Auxiliary Heater Control Module |
| U0326 | Software Incompatibility With Vehicle Immobilizer Control Module |
| U0327 | Software Incompatibility With Vehicle Security Control Module |
| U0328 | Software Incompatibility With Steering Angle Sensor Module |
| U0329 | Software Incompatibility With Steering Column Control Module |
| U0330 | Software Incompatibility With Tire Pressure Monitor Module |
| U0331 | Software Incompatibility With Body Control Module "A" |
Read the codes from your own car
Plug an inexpensive Bluetooth LE or Wi-Fi OBD2 adapter into the port under the dashboard, and Brimly on your iPhone reads the stored, pending and permanent codes, explains each one offline and clears them once the fault is fixed. OBD diagnostics are part of Brimly Forever, a one-time purchase.
Requires iOS 18.1 or later. Free to download, with optional in-app purchases.