Buick Hybrid Stalling: Bad Camshaft Sensor Alert

As someone with moderate experience working on hybrid vehicles, I dealt with nearly identical issues on my 2015 Buick LaCrosse hybrid. The symptoms you describe match exactly what I experienced, rough starts, stalling at idle, and an illuminated check engine light. After sensor testing, my mechanic found the encoder wheel on the camshafts was defective, causing incorrect readings to the engine control module. This led to the engine misfire and starting problems. The repair involved replacing the encoder wheel and recalibrating the camshaft position sensor. Total cost came to 695 Euro, including parts and labor. The crankshaft sensor readings were also checked during diagnostics to rule out other potential causes. Getting this fixed promptly is important since it can lead to more serious engine damage if left unaddressed. To provide more specific guidance for your situation, could you share: Current mileage on your vehicle, Any recent maintenance performed, Whether you notice these issues more during cold starts, If any other warning lights are active, Whether the check engine light is solid or flashing This additional information would help determine if your issue is identical to what I experienced with my vehicle.

Thanks for the detailed reply. My hybrid just had its service at 21405 KM last month where they performed routine maintenance. After reading about your experience with the encoder wheel, I think we might be facing the same issue. My check engine light stays solid rather than flashing, but the ignition timing seems way off based on how rough it runs. Would it be worth having them specifically check the camshaft sensor first since they already verified the fuel system during my recent service?

Thanks for those extra details about your recent service. Based on my experience with the exact same issue on my Buick hybrid, I definitely recommend having them check the camshaft sensor first, especially since the fuel system has already been cleared during your service. The solid check engine light combined with your starting issues strongly points to a sensor failure pattern similar to what I encountered. In my case, the sensor readings were intermittent at first, which is why the check engine light stayed solid rather than flashing. The ignition timing issues you mentioned also match what happened with my vehicle before the repair. The diagnostic process for the camshaft sensor is relatively straightforward and should be the logical first step. When my mechanic tested it, they found the sensor was sending erratic signals due to that faulty encoder wheel I mentioned earlier. The rough running and stalling at idle cleared up completely after the repair. One thing to note, while checking the camshaft sensor, make sure they also verify the crankshaft sensor readings. These sensors work together, and a problem with either one can cause similar symptoms. In my case, even though the crankshaft sensor was fine, testing both helped confirm the exact source of the problem.

Thanks for going into such detail about your similar experience. The symptoms you described with your Buick hybrid match mine perfectly. I will definitely ask my mechanic to focus first on testing both the camshaft position sensor and crankshaft sensor since the fuel system was already checked during my recent service. The solid check engine light and rough running conditions seem to point directly to a sensor failure like you experienced. I called my mechanic and scheduled an appointment for tomorrow morning specifically requesting they test these sensors first. If it does turn out to be the encoder wheel like in your case, at least I now have a good idea of the repair cost and process involved. Really appreciate you sharing your experience, it helps narrow down the diagnostic path and hopefully will save some time identifying the root cause. I will update once I get the results back from the shop.