Engine

P0342 — Camshaft Position Sensor A Circuit Low Input (Bank 1)

Severity: medium Drive with care, to a shop

What P0342 means

The camshaft position sensor tells the engine computer where the camshaft is so it can time fuel injection and spark correctly. P0342 sets when the signal voltage in the sensor A circuit (Bank 1 or the single sensor) stays below the expected range. The usual causes are a failed sensor or wiring that is open or shorted to ground, and less often the ECM.

Symptoms

  • Check engine light on
  • Rough running or misfires
  • Hard starting or no-start
  • Rough or unstable idle
  • Loss of power and hesitation
  • Engine stalling

Possible causes

  1. Failed camshaft position sensor
  2. Damaged wiring or corroded connector pins
  3. Signal wire shorted to ground
  4. Oil contamination at the sensor or connector
  5. Faulty ECM (uncommon)
  6. Mechanical timing problem such as a stretched chain or jumped belt (uncommon)

How to diagnose

  1. Scan for codes and freeze-frame data, and note any crankshaft or other cam sensor codes
  2. Inspect the sensor and connector for oil, moisture, heat damage and a secure fit
  3. Check the harness for chafing, breaks and contact with metal parts
  4. Use a multimeter to verify reference voltage and ground at the connector per the wiring diagram
  5. Test the signal wire for a short to ground and continuity back to the ECM
  6. Inspect the sensor tip and the reluctor or target wheel for damage or metal debris
  7. Check the timing marks and timing drive condition if the electrical tests pass
  8. Use a scope to view the sensor signal while cranking

Common fixes

  • Replace the camshaft position sensor
  • Repair the wiring or replace a corroded connector
  • Clean the connector and fix any oil leak near the sensor
  • Correct the cam timing or replace the chain or belt and tensioners
  • Repair, replace or reprogram the ECM only after everything else is ruled out

Questions and answers

What does P0342 mean?

The ECM is seeing too low a voltage from camshaft position sensor A. The sensor or a wiring short to ground is the most common cause.

Can I drive with P0342?

Only briefly and carefully. The engine may stall or refuse to restart, so get it diagnosed soon.

Will replacing the sensor fix it?

Not always. Check the connector and wiring first, or a new sensor may set the same code.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.