What does it mean?
P1338 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Camshaft Position Sensor (Bank 1) Open/Short to B+ .
Symptoms
- Hard starting or extended cranking, sometimes an outright no-start
- Engine may run but stumble and lack power once it does start
- Stalling at idle or when coming to a stop
- Check engine light on, with cam-related and sometimes misfire codes stored together
- Variable valve timing inoperative, giving weak low-end torque and higher consumption
Likely causes
- Broken or corroded wire in the signal, supply or ground leg of the sensor circuit
- Connector not fully seated, or a terminal pushed out of the housing after service
- Signal wire shorted to a battery-voltage circuit, for example where it runs beside an injector or coil feed
- Internally open sensor winding or a failed hall element
- Blown fuse or open splice feeding the sensor supply, which can also affect other sensors on the same feed
- Water intrusion followed by corrosion that eats the terminal until the circuit opens
- Damaged module pin or an internal module fault, considered only after the harness tests good
How to fix it
- Inspect the sensor connector for a loose lock, a backed-out terminal or corrosion before any electrical testing
- Turn the ignition on and check for the correct supply voltage and a good ground at the sensor connector
- Check the signal wire for battery voltage with the sensor unplugged; voltage where none should be indicates the short to power
- Measure continuity of each wire from the sensor connector to the module pin and repair any open found
- Check the fuse and any shared splice feeding this sensor, since several sensors often share one supply
- Observe the cam signal in live data during cranking; a flat trace with the wiring proven good points to the sensor
- Replace the camshaft position sensor for bank 1, then verify the signal appears and the engine starts normally