What does it mean?
P1342 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Camshaft Position Sensor 'A' Low Input (MRE) .
Symptoms
- Long cranking before the engine fires, or a no-start when the signal is completely lost
- Stalling at idle and a restart that takes noticeably longer than usual
- Rough running with misfire until the module synchronises
- Check engine light on with cam position codes stored
- Weak low-speed torque where variable valve timing is disabled by the fault
Likely causes
- Missing or low supply voltage at the sensor because of an open feed, a blown fuse or a corroded splice
- Signal circuit shorted to ground or dragged low by moisture in the connector
- Failed sensor element, common on magnetoresistive sensors after long heat exposure
- Poor sensor ground caused by a corroded ground eyelet or a broken ground wire
- Excessive air gap or debris on the sensor face, weakening the switching signal
- Damaged target wheel on the camshaft, with worn or contaminated teeth
- Module input pin damage or an internal module fault, checked last
How to fix it
- Check the freeze frame for whether the code sets during cranking or while running, which narrows supply faults versus signal faults
- Inspect the connector for oil and moisture and check that the terminals are tight and not corroded
- With the key on, measure supply voltage and ground quality at the sensor connector before testing the signal
- Backprobe the signal wire during cranking and look for a clean switching pattern; a flat low reading confirms the fault
- Check the signal circuit for a short to ground with the sensor disconnected
- Remove the sensor and inspect its face and the cam target wheel for debris, damage and correct seating
- Replace camshaft position sensor 'A' with the correct type for the engine, then verify the signal and clear the code