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Common Symptoms Of Bad Camshaft Position Sensor (CMP)

Published on December 22nd, 2023

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To discuss the five common symptoms of bad Camshaft Position Sensor (CPS).


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A Camshaft Position Sensor (CPS) is a common vehicle sensor. It measures the rotations and position of the camshaft and transfers this data to the Engine Control Module (ECM). The ECM determines when to time the spark and fuel injected into the engine for the best efficiency.

A damaged Camshaft Position Sensor affects the driving experience and the engine efficiency and can cause more severe conditions.

Symptoms of faulty Camshaft Position

Engine Light Illuminates

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A faulty camshaft position sensor will illuminate your Check Engine Light on the dashboard. If your light comes on you must take your car to be examined by a technician, or you can use our DIY scanner tool to check the vehicle.

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Hard to Start

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"Hard to start" is a common symptom when your Camshaft Position Sensor (CPS) has a problem. Starting takes a little bit longer than usual or doesn't even start at all because the ECM does not get the correct values to time the spark and injected fuel required for engine ignition.

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Rough Idle

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When you start the engine, it idles roughly if the Camshaft Position Sensor has a problem. When the ECM gets the incorrect camshaft data from the sensor, it commands the spark plugs to spark at the wrong time. This causes a misfire resulting in the rough idling.

Poor Engine Performance

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Receiving incorrect data from the Camshaft Position Sensor (CPS) also reduces engine power dramatically. Acceleration is inhibited by misfires and poor combustion. Frequent stalling and engine speed reduction are also clues.

Bad Fuel Consumption

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The incorrect signal from the CPS to the fuel injector causes poor fuel combustion. This inefficiency reduces gas mileage.


The data from the Camshaft Position Sensor (CPS) is important in controlling the engine's operation. Receiving bad information from CPS significantly affects the operation of the vehicle. Therefore, if you encounter the above cases, go to the nearest service garage for immediate repair support.

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