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TuningBot DTC Database · v4.37.15

U302B Ignition Output Accessory/On/Start

Generic (OBD-II) interpretation in the TuningBot DTC database.

U · NetworkNetworkOBD2

What U302B means

U302B
Ignition Output Accessory/On/Start Generic · network Data confidence 65%

The control module detected a fault associated with the Ignition Output Accessory/On/Start circuit or function; the stored code identifies the affected component rather than a single failure mode.

Symptoms

  • Multiple warning lamps possible
  • Functions of the affected module unavailable

Possible causes

  • CAN bus wiring fault (open, short, chafed harness)
  • Faulty control module loading the bus
  • Connector or terminal corrosion
  • Power supply or ground fault of a module

Recommended checks

  • Perform a full-module scan to map which modules communicate
  • Check CAN bus resistance and voltages at the diagnostic connector
  • Inspect wiring and connectors of the affected module
  • Check module power supply and grounds
  • Disconnect suspect modules one at a time only with a documented procedure

Related and nearby codes

How to read U302B

U

Network: communication between control units.

3

Generic SAE-standard code: same meaning on every make.

02B

Specific fault index within the subsystem.

Frequently asked questions about U302B

What does U302B mean?

Ignition Output Accessory/On/Start. The control module detected a fault associated with the Ignition Output Accessory/On/Start circuit or function; the stored code identifies the affected component rather than a single failure mode.

Is U302B generic or manufacturer-specific?

U302B is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.

Can TuningBot remove U302B at file level?

Not guaranteed. Powertrain (P) codes can be reliably disabled in the ECU calibration, but body, chassis and network codes depend on the specific control unit and how the fault is implemented - some can be handled, some cannot. Ask for a quote and our engineers will check your file and tell you, free of charge, whether U302B is removable in your case.

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