P0340
High Severity

P0340 — Camshaft Position Sensor Circuit Malfunction

System: Emissions

What P0340 means

Diagnostic Trouble Code (DTC) P0340 stands for Camshaft Position Sensor Circuit Malfunction. This is a generic OBD2 diagnostic trouble code indicating that the engine computer (ECU) has registered an operational anomaly in the powertrain (p) systems.

When this error registers, the ECU records a freeze frame of sensor data and lights up the Check Engine Light on your dashboard to notify the operator of a system fault.

Symptoms of OBD2 Code P0340

When code P0340 is active, your car might exhibit the following common symptoms:

  • Check Engine Light on
  • Engine cranks but will not start
  • Intermittent stalling or engine stumbling
  • Severe drop in engine power

Common Causes of Code P0340

Faults that trigger this code typically include:

  • Cause 1: Failed Camshaft Position (CMP) Sensor
  • Cause 2: Damaged or corroded CMP sensor wiring connector
  • Cause 3: Weak or discharged car battery
  • Cause 4: Broken timing chain/belt teeth

Can you drive with a P0340 code?

No, the vehicle may stall, fail to start, or enter limp-home mode because the engine computer cannot sync injector firing and spark timing with the pistons.

Expected Repair Cost Band

$80 - $250. CMP sensors are typically inexpensive and mounted accessibly on the cylinder head.

Related Diagnostic Trouble Codes

If you have scanned multiple codes, see these related guides for troubleshooting context:

Frequently Asked Questions

Will a car run with a bad camshaft sensor?

Occasionally, the ECU can run on crankshaft backup maps, but it will have long starting cranks and very poor performance.