Solutions for Toyota C1201 error code

A C1201 Toyota code can be a very challenging problem to diagnose and fix. This is because the trouble code is a general one. The code signals that there is a problem without pointing out the exact issue. However, with an OBD2 scanner, it is easier to find those error codes. 

What is a C1201 error?

This is a code for a Dynamic control system or ABS that is set when you have a diagnostic trouble code stored. The error means that the engine control system has a problem.

If an error is found in the truck engine control system and is detected via the CAN (control area network), it means that the fail-safe feature prevents the TRAC and VSC operations.

When the signals emanating from the engine are standard input, the fail-safe becomes canceled, and the memory fails to store the DTC. 

Description of code C1201

Modern vehicles have various Engine Control Units (ECU) installed in them for superb driving quality. Every Engine Control Unit has its own diagnostic system to communicate with other units within the network, for instance, the CAN bus. If one of these units shows an error or malfunction, its memory will store a fault code.

Besides the error code, some unit functions will be affected or illuminate some warning lights. The DTC c1201 is set due to a malfunctioning of the chassis system.

It might be the electronic stability control or Anti Lock control system. The car manufacturer defines the place and failure of this code. 

What harm can the C1201 Toyota code cause?

The c1201 Toyota code can cause the “Check Engine” light to go on and lead to an unstable operation for the electronic stability control system (ESC) and the antilock wheel system (ABS). 

Causes that trigger the c1201 code in Toyota cars

Here are the causes of the c1201 Toyota code and their solutions. 

1. Performing any work on the steering sensors and suspension 

This is one of the primary and common causes of the C1201 error code. If you do any work on the steering sensors or suspension, then the C1201 trouble code will appear. 


For the stability control system to work correctly, it should know what the sensors send once a vehicle stops on a flat surface. This is what is referred to as zero-point calibration or the calibration procedure. You can carry out this procedure with or without a scanning device.

2. Water in the seed wheel sensor 

3. Damaged Reluctor ring of the wheel speed sensor


  • The first step is to find the car’s source of information. This information will give you the technical Service Bulletins issued by the manufacturer.
  • Check the condition of the ABS module wiring and actuator. Make necessary changes or repairs if you get any damage due to burns, corrosion, or wear. 
  • Scan the vehicle to check for any fault codes. 

Codes related to C1201

  • P1340
  • B2100
  • B1604
  • B1300
  • P1220
  • B1636
  • P1130

How to Troubleshoot Toyota C1201 Code?

To clear the C1201 code, you have to use three related codes. They include the P0455 (Evaporator Emission Control leak detected, a large leak or no purge flow), P0441(Evaporator Emission control system incorrect purge flow and C1201 Engine control system Malfunction. 

The PO codes indicate the presence of gas leaks in the system. This can be in the line near the charcoal canister or the filler torque, but it is primarily a leaky gas cap. It is either the cap that is worn out or mounted wrongly. 

The C1201 code signals the car to turn on the “check engine” light and reduce VSC and traction. This means that the C1201 code lets you know when there is a problem, especially when the other two systems pop up. You can solve this by altering the PO codes as they are the causes of the issue. 

How to Fix C1201 Code?

You can’t fix a C1201 code by replacing the gas lid with a new one. This means you have to find exactly what your car’s C1201 code means and fix the error.

The perception that a new gas cap can clear the vehicle to turn off the check light engine is false and misleading. Fixing the problem is a step of the process you use before opting for an expensive if the code persists. 

The first solution

Here, you need to check and tighten the gas cap and clear all the codes. 

The second solution

Check if the gas cap leaks; if you find it leaking, clean and grease the seal and finally clear the codes. 

Third solution

If you try the above solutions and fail to work, you need to buy an OEM aftermarket gas lid. However, note that you should use a high-quality cap because a low-quality one won’t fix the problem. 

The fourth solution 

While buying a new cap can fix the issue, there are times that it won’t fix it. This means that the light can come back after some time with more problems. So, what are you supposed to do here? So you will find a new but original cap from the aftermarket.

Ensure that the li you are buying contains the actual seal cap. Swap the new seal to the original voila and lid, and your problems will be fully resolved. After you finish fixing, clear all the codes from your computer by either disconnecting your battery or using a code reader. 


The Toyota stability control system obtains input from the yaw sensor, ABS, and declaration sensor. The ABS receives its information from the motor speed sensors. These sensors have a high failure rate; when they fail, they often set a trouble code related to ABS.

This means that you don’t need to track the wheel speed sensor problems if what you get after checking is a C1201 code. If the Toyota vehicle stability control system detects a wheel rock, the car encounters a swerve, skid, or out of control.

When this happens, it operates the ABS brakes and minimizes the engine’s power to attempt to bring it under control.

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