C1201 Toyota Code: Meaning, Causes & How To Fix it

Did you notice a C1201 Toyota code on your scanner? Learn what this code means, how to identify the problem causing it and how to fix it yourself.

C1201 Code

While some trouble codes tell you what’s wrong across all brands, there are a few that are automaker specific. One such example is the C1201 Toyota code. What does this trouble code mean and how should it be fixed?

In this article, we cover the possible definitions of the C1201 diagnostic code on Toyota and Lexus vehicles. We also discuss the symptoms, causes and repairs. 

Code Definition

C1201 – Engine Control System Malfunction

What Does the C1201 Toyota Code Mean?

The C1201 Toyota code indicates a malfunction in the engine control system. It’s used in conjunction with other codes to determine what’s wrong with the vehicle. It could relate to the fuel system, anti-lock brake system, traction control system or emissions, depending on the other codes. 

For this reason, if you get a C1201 code, it’s important to perform a full scan of the system to get a better idea of what’s happening. Look for any other related trouble codes that should get fixed first, and it will most likely also solve this engine code. With these codes in hand, you will be better informed about the necessary steps.

C1201 Trouble Code Symptoms

Because the C1201 trouble code could mean just about anything, this DTC isn’t going to lead to the symptoms that your vehicle is experiencing. All this code is capable of producing is the Check Engine Light. Aside from that, any symptoms that you notice are due to the other faults listed in the code scanner.

The main symptoms of a C1201 code include:

Causes of the C1201 Code

The C1201 Toyota code is set any time that the engine control system malfunctions. Because this can be caused by any defective sensor, system or wiring issue, it’s hard to determine what the cause is without looking at the other trouble codes.

The main causes of a C1201 Toyota code include:

Toyota Engine

How Serious is the C1201 Code?

Medium – It depends on what else is going on with the vehicle. For example, if the problem stems from a broken gas tank cap, you aren’t looking at anything serious. The car will continue to run, although there could be some noticeable performance issues. 

On the other hand, if there’s a faulty wire or sensor, there’s always the possibility that the car will leave you stranded. That’s why you should always have the codes looked at as soon as the Check Engine Light comes on. 

What Repairs Can Fix the C1201 Toyota Code?

A complete diagnostic evaluation must occur before you discover the appropriate fix. We list some steps below to get you started. 

However, here are a few ideas to fix the C1201 Toyota Code. 

  • Replace gas tank cap
  • Replace oxygen sensor
  • Repair EVAP system leak
  • Repair damaged wiring or harness

Common C1201 Diagnosis Mistakes

The most common mistake when working with the C1201 Toyota or Lexus code is failing to look at the other codes. This DTC alone won’t tell you what’s wrong. You need to see what else corresponds to it to determine the cause. 

Some other common codes that tend to relate to this one include:

Recommended Tools for Diagnosis

How to Diagnose the C1201 Toyota Trouble Code

Diagnostic Scanner

If you want to diagnose the C1201 Toyota trouble code, you should follow the same steps as the professional mechanics. As a generic code, the diagnostics will lead you to the system you need to spend more time on. 

Here are some steps to follow:

  1. Clean the diagnostic trouble codes.
  2. Take the vehicle for a test drive until the Check Engine Light comes back on.
  3. Scan for codes again and evaluate all of the new ones in relation to C1201. 
  4. Follow the diagnostic steps to evaluate the other codes that have been set. These will lead you to the appropriate problem.
  5. Once the issue is resolved, clear the codes once again and take a test drive.

You can find more information about Toyota trouble codes and bulletins on their TIS website.

A Mechanic’s Tips on the C1201 Code

Just because the Anti-Lock Brake System or Traction Control Light is on doesn’t necessarily mean that the fault has something to do with these systems. When the engine control system fails to work normally, the Control Area Network (CAN) shuts down the operations of the TRAC and VSC as part of the fail-safe system.

Even if these systems are operating normally, it will appear that there is a problem. Stay focused on the trouble codes that aren’t generic instead. You do also want to check if there is a recall for your Toyota vehicle. Mechanics Tips about the C1201 Code

Estimated Cost of Repair

Depending on the fix that your car needs, you can expect a variety of costs. Here are a few that you might be dealing with and the approximate cost.

  • New gas tank cap – $5-$25
  • New oxygen sensor – $150-$550
  • Repair EVAP system leak – $100-$650
  • Repair damaged wiring or harness – $50-$1,500

Frequently Asked Questions

How to clear code C1201?

To clear the C1201 code, you need to use an OBD2 scanner. However, simply clearing the trouble code memory without repairing the problem causing the C1201 will likely not be a permanent fix. To clear the code for good, you need to determine what is causing it and fix it.

Can you drive with the C1201 code?

To determine if you can drive with C1201 or not, you need to do a full diagnosis because of the many reasons that can cause the C1201 code to appear. If the C1201 code comes on while you are driving, it is safest to drive and turn off the car until you can get it checked out.

How much does it cost to fix the C1201 code?

Fixing the C1201 code can cost anywhere between $0 to $3000. The cost of fixing the C1201 Toyota code varies a lot depending on the specific problem that’s causing the code to be displayed. If you’re lucky, the problem might be something simple like a bad gas cap, which can be fixed relatively easily and inexpensively.


The C1201 code is one of the most common and confusing codes to see on your code scanner in Toyota and Lexus vehicles. However, with a little knowledge and some simple tips, you can easily diagnose and fix the problem yourself without spending too much money.

With the information in this article, you should be able to get your car back on the road in no time. If you feel like you don’t have enough knowledge to fix the C1201 code, contact a professional mechanic!

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Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.

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