Why We Replaced Camshaft Position Sensor But Still Get Code?

Camshaft position sensors require replacements every few months (or when they stop working). That’s normal, isn’t it?

However, some drivers report that the P0340 code errors persist for unknown reasons, even though the sensors are 100% brand-new. Despite their best efforts, it refuses to resolve. How frustrating!

Bryan’s Garage is here to deliver your awaited answer. This insightful article will explain why you replaced camshaft position sensor but still get code – so-called P0340.

Some possible solutions for these dilemmas are also offered to ensure you can get rid of them for good.

Feel ready? Let’s tighten our seatbelts and dive in! 

Why You Replaced Camshaft Position Sensor But Still Get Code? 4 Possible Reasons

Though every model differs from the other, it’s safe to say that at least one of these four triggers is to blame: circuit issues, damaged reluctor wheel, defective sensors, or faulty start motors.

Circuit Problems

Remember that camshaft position sensors always rely on electricity for their smooth runs.

Hence, once the wiring or electrical connector of these sensors encounters unexpected problems, the P0340 error will likely occur.

Bad grounds, loose connections, or damaged wires are also some possible culprits behind the code’s sudden appearance.

Damaged Reluctor Wheels In The Detectors

First of all, it’s important to understand what reluctant wheels are. They refer to several notched wheels tightly attached to your cam-shaft.

Its overall purpose is to pass through the sensor’s teeth and interrupt its magnetic field.

As a result, these wheels generate electric signals used by PCM and ECM. When they get damaged, no electricity supply is available for these two systems, causing the P0340 error to turn its ugly head!

Defective Position Sensors

We cannot rule out the possibility that it’s not the other automobile compartments – but the sensors themselves – that suffer from technical defects.

Though you might argue that it’s new, keep in mind that not every local store sells high-quality products. Your best bet is to get new sensors from a more trustworthy source or retailer!

Faulty Starter Motors

This case is not that common, but it’s still worth a second look if all the other three scenarios do not fit your current situation.

“Starter motor” refers to small-sized electric motors used for engine kick-starting. Untreated defects or faulty operations in these devices will likely lead to a manifestation of the P0340 camshaft code.

How To Fix Check Engine Light Still On After Replacing Crankshaft Position Sensor

There are five methods to fix the error of check engine light still on after replacing camshaft position sensor. Scroll for more detail!

Method 1: Recalibrate or Relearn The Sensor

In most cases, no sensor relearning after replacement means your ECU might still store old data, causing the camshaft position sensor code to turn up.

Hence, we strongly recommend you follow our suggested steps to help the position sensor relearn its information:

Step 1. Switch on your car and connect it to a scanner tool (OBD2). Now turn on OBD2 to choose your model and vehicle brand. Another way is to hit “Auto Detect”, which will read the system automatically.

On another note, if your budget affords it, purchasing a MaxiSys scanner might do the job much quicker.

Step 2. Navigate to “Diagnosis”. Then hit Control Unit > Powertrain > ECM. Once done, enter the section “Special Function” and keep scrolling until you reach “Cam crank relearning”.

A window will pop out, informing you how and when sensor relearning is required. Make sure you read everything from beginning to end to understand what you need to do next. Select OK when you finish.

Step 3. The scanner then asks you to kick-start your engine. Do as it says.

Now, you need to wait for some time until the coolant temperature achieves the required benchmark. You can accelerate your car to increase those temps faster.

Now that the expected temp is reached, your car will start its relearn process immediately without further prompting.

Step 4. Congratulations; you have succeeded! Although small adjustments might be necessary here and there for some cars, most models share the same process as the one instructed above.

Method 2: Check its O-Rings

Each camshaft sensor needs two O-rings simultaneously for proper functioning. One is already fixed to the sensors, and the manufacturers will provide the remaining one.

The former often resembles the sensors’ plastic ridge, leading to people mistakenly assuming they are not there.

For that reason, some drivers try to set up old O-Rings in newer ones, which causes severe installation obstacles and leaves a huge gap inside the detectors.

Thus, it would be best to open the sensor and check these rings again. Did you indeed put O-rings onto new ones? Remove them immediately.

Also, moisture or dirt might be a deathly killer for your car, so remember to clean these rings carefully before installing them.

Method 3: Check and Fix The Sensor Wiring

What if relearning processes fail to remove the dilemma – and that annoying cam sensor code still shows up?

It’s time we turn our attention to the wiring instead, whose ECU signals might undergo problems.

For that precise reason, we should test the wiring harnesses to identify whatever defects are hidden at the moment – and find appropriate ways to fix them! 

The car’s wiring section varies across vehicle brands. For a proper and safe inspection, never forget to trace along with this precise order described below: 

Step 1. Inspect The Wiring Diagrams.

Overall, the sensor will feature three wires in distinct colors (the color codes are not the same for every car, so do your research or ask the manufacturer before starting).

They are called sensor ground, signal, and power supply, respectively.

Step 2. Test The Power Supply

Start getting your hands on the power supplies first, which might require a multimeter. Set it with 1 PIN and inspect the voltage.

Does the voltage fluctuate around 4-5 amp? Then it means the circuit powers still work well.

Step 3. Test The Sensor Ground

Now, observe the ground circuit continuity between ECM and sensor wiring harnesses – using the multimeter we just mentioned in the previous stage.

Guarantee that this continuity still runs well; otherwise, your ground circuit is clearly suffering.

Step 4. Test The Signal Circuit

It will be a deadly mistake to skip the continuity flow between ECM and cam harness connectors! This feature guarantees the sensor’s smooth functioning.

Any defective wire must receive repairs or replacement immediately. Such a task can easily get done at home, but for those without technical knowledge, seeking professional help might be a safer move.

Method 4: Inspect The Reluctor Wheels

Do you still fail to settle the problem with our three methods above? Maybe checking the reluctor wheels can help you here.

After replacing their sensors, many drivers forget about adjusting their Reluctor wheels. Only proper alignments between the sensor and the wheel teeth can ensure their smooth operation!

Most vehicles on the market come with sensors that match the wheel’s 20th teeth, so adjust yours accordingly. Also, investigate whether any teeth got broken, and fix them right away if there is one!

Method 5: Inspect The Timing Chain and Starter Motors

We agree that both of these compartments might not be the first things that come to your mind regarding the P0340 cam shaft sensor code.

Still, if no methods have worked for you so far, a quick look at them might bring surprising results! 

Are these chains rusty, worn down – or worse, broken? Then you must replace them as soon as possible. Service costs might run from $200 to $1000 depending on your vehicle model.

Starter motors should also be considered; their substandard qualities can dampen your signal transfer to ECUs, throwing the P0340 trouble code!

Like with the timing chain, observe whether those motors are cracked or broken. Replace/repair them if the answer is a Yes.

FAQs

What Are Signals of A Failing Cam Sensor?

• The check engine lights are illuminated. It’s one of the most common indicators. Ignoring the light can cause expensive transmission or engine repairs for your car.
• Poor drivability. Failing sensors will lose the ability to transfer data quickly. The mismatch between ignition timing and fuel delivery – even just several milliseconds – makes the vehicle accelerate poorly, sputter, stall, lack power, or even die.
• Transmission shifting issues. Data received from bad sensors will prevent the shifts from operating properly. Some experts refer to such phenomena as “the limping home mode”.

For more analysis of the intake camshaft position sensor, refer to this article.

How Much Does It Cost to Replace Camshaft Detectors?

It’s hard to yield an exact number, but you can be confident that the costs are by no means demanding.

A quick study of some well-known services shows that the average price fluctuates between $100 to $206.

Of course, DIY processes will help cut down the costs even more. Like replacing mass airflow sensors, some simple maintenance steps can be done at home without much effort.

Conclusion

Why we replaced camshaft position sensor but still get code? This article has analyzed possible causes behind the issue and provided five different approaches to resolve it.

Hopefully, the error will no longer dampen your driving experience! If more guidance is still needed, feel free to contact Bryan’s Garage.

Our chatbox and comment section are always welcome for your inquiries!