Your engine’s crankshaft position sensor (CPS) keeps track of the position of your vehicle’s crankshaft. This data is sent to your car’s engine control unit (ECU), so that it can make necessary adjustments.
A failing CPS can cause major problems with your engine’s start-up and acceleration, as well as drastically reduce fuel mileage.
1. Turn off all accessories
If your vehicle is having difficulty starting or idles unevenly, a malfunctioning crankshaft position sensor could be to blame. This sensor plays an integral role in your engine and monitors the rotation speed of your crankshaft.
If it fails, your check engine light may illuminate and reveal serious problems with performance and safety of your vehicle. Furthermore, it could cause a juddering engine.
To restore your crankshaft position sensor’s functionality, reset it. This process will clear out all previous trouble codes associated with your malfunctioning sensor and should take no more than 10 minutes to complete.
To do this, you’ll need to disable all accessories and the fuel system. Additionally, you may disconnect the ignition wires from the ignition coil and distributor if desired.
Prior to trying this reset method, make sure you’ve thoroughly examined and found no physical damage on the scanner’s housing or harness. It is critical that you follow instructions precisely so your crankshaft position sensor remains defective, necessitating replacement.
Another essential step is to clear all trouble codes from your code reader. After doing so, connect it to your car’s computer for further assistance.
If you see a DTC P1336 Crank Relearn Variation Not Learned signal, that’s an indication that your scanner’s Crank Relearn function has been enabled and can now complete the relearn process. This should re-hierarchize the CKP sensor so it can begin learning again; however, if not, repeat these steps until your crankshaft position sensor has fully learned again.
2. Accelerate to 55 mph
If your car’s crankshaft position sensor has become malfunctioning, you may have difficulty starting it and/or your check engine light may be illuminated. Resetting this sensor will clear all stored trouble codes and synchronize all data; this should resolve any issues that have arisen including no-start.
To reset the crankshaft position sensor on your vehicle, first turn off all accessories. Then, accelerate to 55 mph and cruise at this speed for 5-6 minutes.
Once your car reaches 45 mph without using the brakes, maintain it for one minute. Repeat this process four more times with 25 second decelerations between each cycle for 15 seconds each.
This will cause the ECU to forget its short-term memory and relearn how to detect the crankshaft position sensor again, providing it with a corrected reading.
In some cases, this could help solve an issue with the fuel delivery system. If the crankshaft position sensor is not providing accurate information to the ECU, it will impact how fuel filters and injectors deliver fuel into combustion chambers.
If this is the case, the engine’s performance can suffer, leading to poor fuel economy and mileage. In extreme cases, it may even stall when trying to accelerate.
If you’re facing these difficulties, it is critical to get the issue addressed right away. Failure can cause severe engine issues and an expensive repair bill in the future. A qualified mechanic can quickly and efficiently resolve these problems so you can enjoy a secure ride once again.
3. Maintain part throttle
If your vehicle is having difficulty starting, it could be due to a malfunctioning crankshaft position sensor. This component is essential in monitoring the speed of your engine’s crankshaft and enabling your car’s computer to precisely time ignition and fuel injection.
The crankshaft sensor is a coil of wire and magnet that provides information to your engine’s PCM about the rotation speed of its crankshaft. This data allows your PCM to calculate when to start your engine and fuel it appropriately.
A malfunctioning crankshaft sensor can lead to a variety of issues, such as misfiring and the appearance of the check engine light on your dashboard. Alternatively, your vehicle may experience rough idling or shaking while driving.
No matter if it’s with the sensor or engine, there are several ways to fix this problem. One option involves reprogramming your sensor – best left to an experienced technician for accuracy.
Other solutions to consider are either fixing your sensor or replacing it. Repairing a sensor usually costs less than full replacement, but in some cases it may be necessary to completely swap out the entire device.
Reprogramming a crankshaft position sensor is typically an easy process. Simply connect your scan tool to your vehicle’s diagnostic port and follow the onscreen instructions to reacquaint yourself with its parameters.
If the above steps don’t solve your issue, it could be a more serious problem that needs professional repair. If electrical work isn’t your forte, we recommend calling an experienced mechanic to diagnose the problem and suggest the most suitable solution for your vehicle.
4. Decelerate to 45 mph
If your car is experiencing crankshaft sensor trouble and you can’t reset it with a scanner, there are some manual methods you can try. These procedures have been known to work for most cars and will get you back on the road quickly.
To reset your sensor without a scanner, turn off all accessories and accelerate to 55 mph while maintaining part throttle. Cruise at this speed for 5-6 minutes.
Following that, decelerate to 45 mph without using brakes for one minute. Come back to 45 mph between those deceleration cycles for 15 seconds, then accelerate back up to 55 mph and cruise at this pace for several more minutes.
If all goes according to plan, this should complete the reset process of the CPS. However, if it doesn’t succeed, something else may have gone awry with your system and professional assistance is recommended.
You may also try to reset your CPS with a code scanner if available. The scanner will help clear any previous trouble codes associated with a defective crankshaft position sensor and then it will begin learning the new sensor.
Furthermore, the scanner can help identify any errors your ECU may be having and even assist with relearning the camshaft position sensor if required. Unfortunately, this procedure can be quite complex so make sure to follow along with all instructions carefully.
If you don’t know how to do this yourself or the process seems overwhelming, visiting your local mechanic may be necessary. However, you could always attempt it yourself and see if it works out for you.
5. Maintain 45 mph
The crankshaft position sensor is an essential element of the engine, providing data to the ECU about vehicle position and speed. Without this data, the ECU cannot decide how much fuel should be injected into combustion chamber or when to ignite it. If malfunctioning occurs with this sensor, many issues in powertrain may arise.
To reset a crankshaft position sensor that won’t start, first turn off all accessories and accelerate to 55 mph before decelerating back down to 45 mph for several minutes. This will allow your engine to reach its ideal operating temperature, relearning its crankshaft position sensor and clearing any trouble codes stored in the system.
However, you must maintain 45 mph throughout the process in order to guarantee that the system synchronizes its data without creating any further issues. After finishing up with CPS installation, you should be able to drive your vehicle normally with no further issues caused by it.
If the above method does not solve your problem, there may be something amiss with either the wiring connections or crankshaft position sensor itself. In such cases, professional assistance is recommended to resolve the issue. This can be done either using a scanner or manually relearning the crankshaft position sensor. Either way, the steps are fairly straightforward – the only issue being that it may take some time to complete everything correctly.