Toyota C1201 Code Problems and Troubleshoot

Toyota C1201 error codes are very common and they can be caused by many different things. We’ll help you figure out what the problem is so you can fix it yourself.

However to make it easy to find out the exact issue, then you need to use an OBD2 scanner to find out the Toyota C1201 Code problems and how to troubleshoot them.

Here is a Detail of the Toyota C1201 Code Problems and Troubleshoot Guide

In this guide, we’ll talk about what the code c1201 stands for and what it does. how it directly impacts vehicle engine health, including causes, and how do I fix c1201 code.

Definition of C1201

C1201 – Engine Control System Malfunction

What is Mean By C1201 Code?

The common Toyota trouble code C1201 doesn’t provide much additional information. To figure out what’s wrong with the car, it’s performed in combination with other codes. Depending on the other codes, it can be related to the fuel system, anti-lock brake system, traction control system, or emissions.

What is a C1201 error?

When you have a stored diagnostic fault code, this code for a dynamic control system or ABS is set. The malfunctioning engine control system is indicated by the error. The fail-safe function inhibits the TRAC and VSC operations if an issue is discovered in the truck engine control system and is discovered via the CAN (control area network).

Trouble Code C1201 Symptoms

This DTC won’t cause the symptoms that your vehicle is experiencing, so the C1201 trouble code could mean more or less anything. The Check Engine Light is the only thing this code is capable of producing. Other than that, any symptoms you encounter are the result of one of the other errors the code scanner lists.

For instance: 

  • The Anti-lock Braking System and Electronic Stability Control System are both prone to failure.
  • The check engine light is on.
  • Rough engine performance
  • Decreased fuel economy

C1201 TOYOTA Common Reason for this fault

  1. Large Evaporation system leak
  2. Loose/faulty Gas cap
  3. Faulty oxygen sensor
  4. Damaged wiring or harness

How to Troubleshoot Toyota C1201 Code?

Here is a list of Toyota Brands that were directly affected by this problem; so, for specific models indicated below, you can follow these troubleshooting procedures.

  • Toyota Vellfire

  • Toyota Fortuner

  • Toyota Avensis

  • Toyota Tundra

  • Toyota Camry

  • Toyota 4Runner

  • Toyota Aygo

  • Toyota Land Cruiser

  • Lexus

  • Rav4

  • Toyota Highlander

Three Codes are related to each other to clear the C1201 Code.

  • P0455: Evaporator Emission Control System Leak Detected (no purge flow or large leak)

When the Evaporative Emission Control (EVAP) system develops a leak and the pressure within the system drops, a P0455 DTC is generated.

  • P0441: Evaporator Emission Control System Incorrect Purge Flow

The P0441 error number indicates that the EVP system in your vehicle is receiving an improper purge flow.

  • C1201: Engine Control System Malfunction

In addition to problems with your vehicle’s traction control system, the C1201 code can indicate a problem with the Anti-Lock Braking System (ABS).

The two P0 codes suggest an emission leak in the system. Technically it may be in the filler collar or the line to the charcoal canister, but for the most part, it’s just a leaky gas cap. Either a cap wrongly mounted or one worn out.

The C1201 code is the one that tells the vehicle to turn on the light of the check engine and to disable the traction and VSC. Basically, when the other two codes pop up, this one is responsible for letting you know that there is a problem there. This can also be solved by changing the other codes because they are the ones that caused it.

Codes of Toyota 4Runner

Toyota Rav4 Transmission Problem   

How to Fix Toyota C1201 Code?

  1. Replace gas tank cap
  2. Replace oxygen sensor
  3. Repair EVAP system leak
  4. Repair damaged wiring or harness

How to Replace Gas Tank Cap?

  • A new gas cap is definitely not going to fix your problem. You’ll have to find out what yours means and fix the problem.
  • There is a false perception that newly gas cap would clear the vehicle into turning the check engine light off. It’s not – unless it was the problem in the first place.
  • It’s a step of the process you have to go through to fix a code by applying a simple solution before going for an expensive one if it is not fixed.

Solution 1

Tighten the gas cap and clear the codes, (They came back approximately 4-5 restarts later).

Solution 2

If the cap was leaking, then Clean and grease the gas cap’s seal and clear the codes.

The result was the same as Solution #1

Solution 3

If above method didn’t work then purchase an OEM aftermarket gas cap, don’t try to put a low-quality cap, it will not fix the problem.

Solution 4

Sometimes the new seal cap wouldn’t fix the issue, after a few days the light came back with the same issues then what you have to do.

Find the original cap from aftermarket and make sure it has an original seal cap swapped the new seal onto the original cap and voila! Problem solved

After any of these fixes, you’ll need to clear the codes from the computer. You can either use your code reader to do this the easy way, or disconnect your battery for 10 minutes or so.

Other 3 Remaining Problems 

You cannot fix other 3 issues unless you have mechanical expertise, therefore better to take your car to an expert mechanic.

Depending on the problem your car has, the cost to fix other remaining issues will range from 30 to 2200 US dollars.

How to Diagnose the C1201 Trouble Code

You should take the same techniques as expert mechanics if you wish to diagnose the C1201 issue code. The diagnostics will direct you to the system you need to spend more effort on as a generic code.

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.

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If All These Methods Wouldn’t Work Against Toyota C1201 Code Problems and Troubleshoot

Then, look at the rest of the areas. This is where things could get costly. Perhaps it is safer to take it to a shop that can check it. The fuel filler collar, the charcoal canister, and the VSV valve will be areas of concern.

According to Toyota Support Center About this particular problem

Toyota C1201 Code Problems and Troubleshoot