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U0030

Powertrain Sensor Data Bus

A fault has been detected on the dedicated powertrain sensor data bus (a sub-bus used for high-speed sensor data such as crank, knock or wheel-speed). Symptoms range from rough running to limp-home, depending on which sensor stream is missing.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: hard

Symptoms

  • Multiple warning lights may illuminate
  • Affected modules may go into limp mode or shut down
  • Specific functions inoperative depending on module
  • Diagnostic tools may show communication faults

Common causes

Ordered by how often each turns out to be the cause.

  • Sensor data bus wiring damagedCommon
  • Sensor module on bus failedPossible
  • Gateway module routing CAN messages incorrectlyLess likely

Parts involved

  • Sensor Data Bus
  • CAN Bus Wiring

U0030 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.