P1843 code — how to fix error fast

Your vehicle’s transmission system is the heart of the car along with the engine, and it’s no wonder that most drivers panic when they see the P1843 code showing up on the scanner tool. It’s one of the most common codes related to the hydraulic pressure within the system, so it’s natural that you’ll need to find a quick solution.

Perhaps this guide on the P1843 code meaning will motivate you to look at the issue in closer detail so you can find an appropriate fix. Don’t worry, we’ll also tell you how to deal with the issue behind it and remove the code once and for all.

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What does the P1843 code mean?

The P1843 code stands for “Transmission Fluid Pressure Sensor/Switch F Circuit High.” It means that there is a high voltage signal detected in the transmission fluid pressure sensor circuit.

This can cause the transmission to shift erratically or not at all, leading to a range of symptoms such as decreased fuel efficiency, difficulty shifting gears, and even transmission failure.

What causes the P1843 code?

Several factors can cause the P1843 code, such as a faulty transmission fluid pressure sensor, damaged electrical wiring, or a malfunctioning transmission control module. Let’s take a closer look at each potential cause.

Faulty transmission fluid pressure sensor

The transmission fluid pressure sensor is responsible for monitoring the amount of pressure in the transmission fluid. If it is malfunctioning, it can send incorrect signals to the transmission control module, causing the P1843 code to appear.

Damaged electrical wiring

Damaged electrical wiring can also cause the P1843 code. If any wires in the transmission fluid pressure sensor circuit are frayed, corroded, or broken, it can disrupt the flow of electrical signals and trigger the code.

Malfunctioning transmission control module

The transmission control module is responsible for regulating the transmission’s performance based on the signals received from the transmission fluid pressure sensor. If it is malfunctioning, it can send incorrect signals to the transmission, causing the code to appear.

Which car models does the P1843 code affect the most?

The P1843 code can affect a range of car models, but certain vehicles are more prone to experiencing this issue. These include Dodge Ram, Jeep Grand Cherokee, and Chrysler 300. The reason for this is that these models use a similar transmission system that is more susceptible to transmission fluid pressure sensor circuit issues, so let’s take a closer look:

• Dodge RAM: This vehicle has faced frequent issues with the TCM over the years in cars equipped with an automatic gearbox, which often led to drivers experiencing the code P1843.
• Chrysler 300C: Problems with the failing transmission fluid pressure sensor in this vehicle have led to drivers struggling with figuring out the transmission fluid level.
• Jeep Grand Cherokee: Finally, the Grand Cherokee is yet another vehicle that’s said to be affected by the code due to TCM-related issues.

How to diagnose the P1843 code

Diagnosing the P1843 code requires specialized diagnostic tools and equipment. Here are the steps to diagnose the code:

Check for other codes

Before diagnosing the P1843 code, it is essential to check for any other codes that may be present. This can help narrow down the potential causes of the issue.

Inspect the electrical wiring

Inspect the electrical wiring in the transmission fluid pressure sensor circuit for any signs of damage, such as frayed wires or corroded connections.

Check the transmission fluid pressure sensor

Check the transmission fluid pressure sensor for any signs of damage or wear, such as cracks or leaks.

Test the TCM

Finally, you can also test the transmission control module using specialized diagnostic tools to determine if it is malfunctioning and causing the P1843 code.

How to fix the P1843 code

Fixing the P1843 code depends on the underlying cause of the issue. Here are the steps to fix the code:

Replace a faulty sensor

If the transmission fluid pressure sensor is faulty, it will need to be replaced. The cost of replacing the sensor can range from $100 to $500, depending on the make and model of your vehicle.

Deal with wiring damage

If the electrical wiring is damaged, it will need to be repaired or replaced. The cost of repairing or replacing the wiring can range from $50 to $200, depending on the extent of the damage.

Repair the TCM

Repairing TCM damage can also be pretty expensive especially if the module has failed and you need to replace it which can cost up to $1500. However, you should also be able to reset the software programming in most cases which can be an easier fix.

How to prevent the P1843 code

Preventative measures can help prevent the P1843 code from appearing. Here are some tips:

• Perform regular transmission fluid changes
• Check the TCM in case you notice odd or rough gear shifts
• Properly maintain the transmission according to the manufacturer’s specifications

Properly maintain the transmission fluid pressure sensor circuit by keeping it clean and free of debris. This can help prevent damage to the system and reduce the likelihood of the code appearing.

Our take

Overall, the P1843 code is a serious issue that can cause a range of problems for your vehicle. Understanding the code, its causes, diagnosis, fixes, and preventative measures can help you keep your car running smoothly and prevent further damage.