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C1201 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


C1201 is an OBD-II Code that refers to TOYOTA Code - Engine Control System Malfunction


When a C1201 code is detected via the Control Area Network (CAN), VSC and TRAC are shut down by the fail-safe mechanism. When the engine signals are received correctly, the fail-safe is disabled, and the DTC is recorded.


Common causes for this code include:

  • The Wheel Speed Sensor may be wet.
  • The wheel speed sensor's reluctor ring may be damaged.


The symptoms of a C1201 code are:

  • The Anti-lock Braking System and the Electronic Stability Control System are both prone to failure.
  • The check engine light is on.


To diagnose a C1201 DTC code, a technician would:

1. Inspect the wheel speed sensor reluctor ring for damage.

2. Inspect the wiring and connectors of the wheel speed sensor for damage.

3. If there is no trouble found on the previous two inspections, then replace the individual component that has been inspected.

Common mistakes

The following are common mistakes when diagnosing the trouble code C1201:

Trying to diagnose the problem without checking first on the wheel speed sensor: it's always first.

Assuming that the DTC will not be stored unless there is a problem with the wheel speed sensor: wrong. It can be stored whether or not there is a fault, and trigger even if there is no speedometer output.

How serious is this?

A C1201 code is a Critical Trouble Code, which means that the ECM is not able to work with the Electronic Stability Control System and Anti-lock Braking System. As this may lead to accidents, it is important to have them fixed as soon as possible.

What repairs can fix the code?

Repair manuals
Repair manuals

The following are solutions that may fix this problem:

  1. Check the wheel speed sensor reluctor ring for damage.
  2. Replace the individual component that has been inspected.

Related codes

A C1201 is related to and may be accompanied by the following codes:

B1000, P1125, P1116, P1031, B1638, P1405, P1443, B1634, B1676, P1340, B1604, P1409

How much does it cost to fix the C1201 code?

The repair cost of a C1201 code varies depending on the type of component that needs to be fixed. Labor costs are around $100 while parts are between $50 and $200 or more.


In conclusion, the C1201 code means that there is a problem within the Electronic Stability Control System and Anti-lock Braking System, which means that this code should be fixed as soon as possible. It's always best to take care of your vehicle before something goes wrong.

C1201 code – what does it mean & how to fix it



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