P0344 is an OBDII diagnostic code. It is a generic code, which means that it has the same meaning for the GMC Sierra as it would any other vehicle. If your Sierra has this code, it means that the PCM (powertrain control module) has detected that the camshaft position circuit is sending an intermittent signal.
Your camshaft position sensor sends a signal back to the PCM when the ignition is on. Its job is to measure the rotational position of the camshaft. This information is used to control engine performance and timing, and is checked against the crankshaft position sensor.
An intermittent signal means that the signal coming from this sensor is failing to reach the PCM at certain points. The PCM will then trip the check engine light and you’ll get P0344.
P0344 is usually caused by an intermittent electrical fault. That fault is usually caused by an issue coming from your Sierra’s camshaft position sensor, or the sensor itself.
P0344 Symptoms: GMC Sierra
The symptoms of P0344 can vary quite a bit. In some cases, the only thing that the driver may notice is the check engine light. In other cases, your Sierra may not start at all.
- Check Engine Light– This is often the only symptom of P0344.
- No Start– Without data from the camshaft position sensor, it’s quite common to get a no start from your Sierra. The engine will crank, but that’s it.
- Tough to Start– If the camshaft position sensor is sending an intermittent signal, it might be enough to get the engine started, but it may take longer than normal.
- Rattling Sound– This indicates that there may be an issue with the camshaft position sensor itself.
- Lost Power– Without a strong signal from the camshaft position sensor, it is common for engine power to suffer.
P0344 Causes: GMC Sierra
Here are some of the most common causes of P0344:
Wiring Issues: Camshaft Position Sensor
One of the most common causes of P0344 is wiring related. If there is an open or short between the wiring harness and PCM, the signal will be intermittent. Make sure that the wiring harness is seated well into the camshaft position sensor and not damaged in any way.
An inspection of the wiring harness is a great place to start looking for the cause of P0344. You’ll want to look for cracked, burnt, or exposed wiring, and inspect the harness plugs.
Bad Camshaft Position Sensor
The camshaft position sensor itself can go bad over time. It will no longer be able to send a signal to the PCM and your Sierra will get the intermittent P0344 code.
Battery
P0344 is know to be triggered by a battery that has low/no charge. If you’ve recently tried to start your Sierra with a battery like this, that may be what threw the code. If there are no other symptoms other than P0344, and the battery was low/dead, it’s highly likely that’s what caused it.
Starter
A bad starter or wiring issue in the starter system circuit can cause P0344. It’s not nearly as common as the camshaft position sensor or it’s wiring to have gone bad.
Conclusion: P0344 GMC Sierra
This is one of the more commonly misdiagnosed codes. Be thorough in your inspection of the wiring harness. That’s usually the cause. Also, the signal may be intermittent now, but it might not be long before it gets worse and your Sierra won’t start at all. Try and get it repaired as soon as possible. Good luck!