OBD Codes List

Diagnostic reference · P34C3

P34C3

B Camshaft Position Actuator Position Sensor A Circuit High Bank 2

System
Auxiliary emission controls (P code)
Lamp
Check Engine Light
Category
Powertrain - Auxiliary Emissions Controls

What it means

P34C3 stands for B Camshaft Position Actuator Position Sensor A Circuit High Bank 2. P34C3 is a P code, so the fault sits in the engine, transmission and emissions systems. For P34C3, the second digit places it in auxiliary emission controls. For P34C3, work through the cause list below, cheapest checks first.

Where it lives

For P34C3, the sensor sits on the circuit this code reports. The description of P34C3 puts it on bank 2.

What to check first

For P34C3, compare the reading on bank 2 against the other bank on the same scan tool, because a bank that reads differently from its twin is the fault.

Check these first

  • P34C3: Carbon buildup or blockage in the EGR, EVAP, or air injection system
  • P34C3: Failed solenoid, valve, or pump in the auxiliary emissions circuit
  • P34C3: Wiring, connector, or fuse fault for the emission component
  • P34C3: Small leaks in vacuum or EVAP lines
  • P34C3: Failing catalytic converter or oxygen sensor reporting incorrectly

What to do next

P34C3 is a fault in the auxiliary emission controls system. The steps below are general, so what actually failed on your vehicle may not be what P34C3 names.

  1. P34C3: Read related codes and freeze frame with an OBD-II scanner
  2. P34C3: Inspect hoses, valves, and solenoids for leaks, cracks, or carbon buildup
  3. P34C3: Smoke test the EVAP or intake system if a leak is suspected
  4. P34C3: Command components on/off with a scan tool and watch them respond
  5. P34C3: Clean or replace the blocked or failed component

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Updated

Generic SAE J2012 definition. Last updated 2026-08-30.