How To Troubleshoot & Fix p161B Jeep Patriot DTC Code?

You can’t just take any Diagnostic Trouble Codes lightly, as they often indicate an error you need to fix to run your Jeep smoothly. The scenario remains the same in the case of Code P161B on your Jeep Patriot. But no worries! 

We often see many owners deal with the p161B Patriot code. Compared to other DTC codes, p161B is a bit complicated. But it can be fixed. 

What Does p161B Jeep Patriot Code Mean?

There is a calculated checksum value stored in your Jeep Patriot. Besides, your Jeep’s transmission Control Module (TCM) also calculates the numerical checksum value. 

But if the stored checksum value doesn’t match the value or data the transmission control module gained, the code p161B occurs. 

And by this code, the computer system in your Jeep Patriot alerts you that there is something wrong with the battery or the transmission control model in your Jeep Patriot. 

To be more precise, the p161B code simply means “Battery Disconnected/ TCM Internal.” Now let’s elaborate on the DTC code below. 

  • P= Powertrain Control Module. P indicates the transmission or drivetrain.
  • 1= A generic manufacturer-specific code derived from the SAE standard. 
  • 6= Most probably it indicates battery related issue 
  • 1B= Specific fault index. ( “Battery Disconnected/ TCM Internal.” )

P161B Code: What Causes Battery Disconnected/ TCM Internal on Patriot?

Many issues, simultaneously or individually, can cause the DTC code p161B on your Jeep Patriot. 

And most of the issues are related to the transmission control module, which is responsible for controlling your Jeep’s transmission system.

Once you know the possible causes of the problem, you’ll find a lot of ease while solving the problem. 

Even if you go with the mechanic, you can adequately understand the reasoning behind the DTC code. Now let’s have a look at the causes. 

  • Lose or Damaged Wiring Harness. 
  • Dead Battery.
  • Faulty Alternator.
  • Faulty TCM software calibration.
  • Damaged or Worn out harness of the transmission control module. 
  • Faulty transmission control module (TCM).

According to Autocodes, their webpage related to the code gets around 36,000 views. This data shows how popular or, you can say, extreme the code is. Besides, according to Car Complaints, we have seen 855 complaints about the Jeep Patriot.

Read Also: How to Troubleshoot & Fix U1504 Jeep Cherokee Code?

How to Troubleshoot & Fix p161B Patriot Code?

You are now well aware of the possible reasons behind the Patriot code p161B. Here, we will check and fix the causes one by one. 

In this troubleshooting guide, first, we will introduce you to the causes, how they can impact the code to occur, and ways to get rid of them. . 

Check and Fix the Bad Battery Connection (Source)

As the code means ‘Battery Disconnected’ along with ‘TCM Internal,’ this indicates there might be something not good with the battery. 

And chances are the battery connection becomes loose or the wiring harness becomes damaged. If this happens, the battery can’t charge properly. 

And due to a lack of battery charge, the transmission control module of your Jeep SUV might start to malfunction. 

The transmission control system needs power from the battery in order to control the transmission. Moreover,  it needs constant power for minimal operation from the battery. 

The transmission control module can’t calculate the checksum data properly if it can’t get power. 

As the day advances, the wiring harness of the battery in your Jeep might wear out or be damaged. 

So, you need to check the wiring harness visually to see any further damage. If you find any damage or the wiring harness is worn out, you should replace it.

Check and Replace the Dead Battery

If you find no major issues with the wiring harness, then it makes all sense to check if the battery is dead. The transmission control module cannot function when the battery on your Jeep malfunctions.

And suppose the transmission control module of your Jeep Patriot is not functioning properly due to power interruption. 

In that case, there is a mismatch between the calculated stored checksum value and the checksum value acquired by the transmission control module. For this, the Patriot code p161B can take place. 

What you need to do here is to check if the battery is dead using a multimeter. Now, this can be tricky if you don’t have a decent idea about checking the battery or don’t have the multimeter. 

Therefore,  it will be better if you go with the mechanic. And if the battery turns out dead or the lasting period is finished, you should replace it, which might cost you $340-$400.

Read Also: How to Troubleshoot & Fix U1411 Jeep Liberty Code?

Check and Replace/Repair the Faulty Alternator

If there is no issue with the battery and connections, check the alternator. Due to a faulty alternator, your Jeep’s transmission system might malfunction even though there is no issue with the battery. 

This is because the alternator in your Jeep converts chemical energy to electrical energy. And in this way, the battery becomes charged when you drive your Jeep patriot.  

But because of a bad alternator, your patriot SUV’s battery may run out of charge. This is how low battery voltage occurs, and the code p161B takes place, meaning disconnected battery or low battery voltage. 

By this, the TCM of your jeep is negatively affected as it runs on the power from the battery. 

In such a case, you need to check the faulty alternator of your jeep. Besides, check the wiring harness connected to it. 

If the alternator is bad and can’t transfer electrical power to the battery, you need to repair or replace the alternator based on the severity of the problem.

Replacing the alternator of your Patriot might cost you approximately $800-$9000. You can watch this video to check the faulty alternator in your Jeep Patriot. 

4: Check and Update Faulty TCM Software Calibration

Next, Sometimes, your Jeep Patriot’s transmission control module software needs to be correctly calibrated. This can happen due to software update issues. 

Also, your patriot’s transmission control module system needs to be correctly programmed.

If the transmission module software is calibrated, the transmission control module can calculate the checksum value, which doesn’t match the stored checksum data. For this, when you see the troubleshooting code, it indicates ‘TCM internal.’

Now what you need to do is to check whether the transmission control module software is updated. If not, then you have to update the software. We hope this can fix the issue for you.

Read Also: How To Troubleshoot & Fix P0441 Jeep DTC Code?

Check and Replace the Damaged or Worn-Out Harness of the Transmission Control Module

This is not surprising at all that due to damage or worn-out wiring harness of the transmission control module can malfunction. The wiring harness is connected to different sensors on the Jeep. 

And with the help of the wiring harness, the transmission control module communicates with the sensors and gets readings. 

Now, if the wiring harness of the transmission control module is bad, it can’t get correct data from different sensors. 

And for this, the stored checksum data doesn’t match the data collected by the transmission control module. Your jeep’s computer thinks there’s something wrong with the TCM and shows the code p161B. 

The solution to this problem is simple; first, you need to check the wiring harness of the transmission control module. 

If they are damaged or worn out, it is better to replace the wiring harness to ensure the TCM can function properly. 

6: Check and Replace the Faulty Transmission Control Module

You can never expect the transmission control module of your jeep patriot to function properly if it becomes faulty. 

And one of the core reasons behind code p161B is the faulty transmission control module, even if its wiring harness is fine. 

There are many reasons why the transmission control module of your jeep might go bad. Among them, major electrical issues and physical damage are the most common. Sometimes, there can be a loss of TCM, or it can be damaged. 

When the TCM in your jeep patriot malfunctions, it can produce an incorrect message or corrupted information, meaning that the calculated checksum data won’t match the stored data.

You can check the electrical connection of the transmission control module. If the connection is fine, then you should check the TCM to see whether you find any physical damage on the TCM of your jeep. 

Above all, you need to check the TCM carefully and replace it if it becomes bad.

Read Also: How To Troubleshoot & Fix P1391 Jeep Code? Detailed Guideline!

Frequently Asked Questions

Here, you’ll know some of the most asked questions from the Jeep Patriot owners who deal with the code p161B code on the Jeep Patriot. You might have these questions to ask as well. 

Can You Drive a Jeep Patriot With p161B Code?

No, experts suggest not to drive your jeep patriot unless you reset or troubleshoot the code p161B. This is because the issues that cause the problems are pretty severe. And, if you drive your patriot with the issues, you might fall into trouble. 

How Much Does It Cost to Fix Jeep Patriot p161B Code?

The repairing cost of code p161B depends on what components cause the issues. For example, replacing the transmission control module (TCM) will cost around $700-$900, including parts and labor costs. It’s better to know the replacement cost from the mechanic. 

Can You Fix the Jeep Patriot Code p161B on Your Own?

It depends on how much knowledge you have regarding your Jeep. Additionally, if any minor issue like a worn-out battery wiring harness causes the issue, you can fix it. However, if you have to replace anything like TCM, you might need help from a mechanic. 

Final Thoughts

There you have it. whenever you detect the p161B code on your Patriot, don’t make any further delay. Rather, attempt to fix the issue as soon as you can. Find the root cause of the code, since there can be many reasons, and choose the best way to solve it.

Read Also: How To Troubleshoot & Fix P0456 Jeep Wrangler DTC Code?

Scroll to Top