Crankshaft Positions Sensors : Daewoo Leganza 2.2 L 131 hp Gas - 2000

Crankshaft Position Sensor Symptoms

There are a number of reasons why a crankshaft position sensor can fail and a number of symptoms associated with that failure. Problems with the crankshaft sensor will often present as problems with engine timing. If you think your sensor has failed, here are some common symptoms of a bad crankshaft sensor that can help you in determining whether or not it has failed.

1. Acceleration Problems
As the engine speeds up, there needs to be adjustments to spark timing and fuel injection. Without accurate input from the crankshaft sensor, the ECU can't make these adjustments as well as it should. This can result in slow or uneven acceleration.
 
2. Reduced Gas Mileage
Without accurate timing information fuel injection won't occur as efficiently as it should. That means the engine will need to use more gas and your morning commute will use up more fuel than usual.
 
3. Engine Misfires
Lack of proper spark timing can cause a different problem: one or more of the cylinders may misfire. That is to say combustion may be disrupted. You will feel, and maybe hear, this as a brief stutter in the engine.
 
4. Rough Idling
You might feel that the engine runs rough or vibrates at idle, say, when you're sitting at a red light. This is similar to the above in that it stems from poor spark timing.
 
5. Stalling
As seen with rough idling, sometimes crankshaft sensor problems are worse at low engine speeds. Sometimes the engine might even stall out entirely at low speed if the fuel injectors aren't giving it the fuel it needs.
 
6. Difficult Starting or No Starting
It might be hard to get your engine started without the fuel it needs or without proper timing. If the crankshaft sensor has failed completely, and isn't sending a signal to the ECU at all, then the computer won't send any fuel to the injectors. This will leave you unable to start the car.
 
7. Check Engine Light
A failing or failed crankshaft position sensor may cause the check engine light on your dashboard to come on. A diagnostic scan tool will show a code between P0335 and P0338. The check engine light doesn't always come on, though, so you could be experiencing any of the above symptoms for some time before you see the warning light.
 
8. Related Issues
There are a number of different problems that can cause similar symptoms to a crankshaft position sensor problem. Many of the issues mentioned above can be caused by failures in the ignition system or fuel injection system. Before you conclude that the crankshaft position sensor is bad you may need to run some tests.

Does This Sound Like Your Car ?
If you are experiencing the problems mentioned above, then it may very well be time to replace your bad crankshaft position sensor. However, before you replace it, you might want to run some tests first to confirm that the crank sensor really is the source of the problem.

How the crankshaft position sensor is tested

Whenever there is a suspicion that the problem might be caused by a crankshaft position sensor or if there is a related trouble code, the sensor must be visually inspected for cracks, loose connector pins or other obvious damage. The proper gap between the tip of the sensor and the reluctor wheel is also very important.
Typically for the pick-up coil type sensors, the inspection involves checking the resistance. For example, for the 2008 Ford Escape, the resistance of the crankshaft position sensor (CKP) should be between 250-1,000 ohms, according to Autozone. We measured 285.6 ohms (in the photo), which is within specifications. If the resistance is lower or higher than specified, the sensor must be replaced.
For the Hall-type sensors, the reference voltage (typically +5V) and the ground signal must be tested. The most accurate way to test a crankshaft position sensor is checking the sensor signal with an oscilloscope.
 
Sometimes, the sensor may have an intermittent fault that is not present during testing. In this case checking for Technical Service Bulletins (TSBs) and researching common problems may help. For example, the crankshaft position sensor failure was very common in some early-90's GM cars. One of the symptoms was stalling when the engine is hot. According to many owners at various forums, the new crankshaft position sensor solved the problem.
 
The crankshaft position sensor can be checked with a scan tool, that shows it as "Engine RPM" or "Engine speed." For example, if the sensor causes intermittent stalling, you might be able to see that when the engine stalls, the RPM signal drops suddenly to zero, as oppose to slowing down gradually. If the RPM signal suddenly drops to zero means that the signal from the crankshaft position sensor is lost. If the sensor works properly, the RPM signal should drop or rise gradually, as in this photo. We have tested this car with an OBDII "Torque" app on the mobile phone.

 

Crankshaft sensor replacement

Replacing a crankshaft position sensor is not very expensive. The part can cost from 35€ to 115€ and it's best to use an OEM part. In most cars it's fairly easy to replace, although sometimes the sensor could be difficult to remove due to corrosion.
 
 

How prevent the good condition of your engine ? Try CARBON CLEANING ! Maintains and clean effectively your engine. Preventive engine cleaning enables you to restore engine parts rather than replacing them, thereby saving vehicle owners on costly parts, such as a new turbocharger (1.350€ - 3.100€), catalytic converter (600€ - 2.000€), DPF (600€ - 2.000€) or EGR valve (370€ - 500€). These problems result mainly from poor combustion, which stifles the engine. So before replacing your engine parts, try Carbon Cleaning. A dirty engine as the result of carbon deposits is the new threat to vehicle performance.

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