P0901 code definition
When the PCM (powertrain control module) detects that the clutch actuator circuit is not performing within the range determined by the manufacturer, it will record a P0901 code and illuminate the Check Engine light.
What the P0901 code means
In a fully automatic or semi-automatic transmission (SAT), the vehicle will determine the best time to shift when the TCM (transmission control module) gets the correct input signals and sends a command to the clutch actuator. If the PCM gets an input signal that identifies a problem with the clutch actuator’s performance, the code will be stored.
What causes the P0901 code?
The most common causes for a P0901 code to be stored include:
- A faulty clutch actuator
- An open circuit to the clutch actuator
- A loose or disconnected ground
- A faulty solenoid
- A problem with the TCM or PCM (rare)
What are the symptoms of the P0901 code?
In most cases, in addition to the illumination of the Check Engine light, the driver will generally notice harsh shifting. The clutch may also fail to engage or disengage.
How does a mechanic diagnose the P0901 code?
After determining the presence of the P0901 code and any related codes (P0900) is also a common code that shows up in relation to the P0901 code, as are P0902 and P0903. If a P0900 code is detected, it should be addressed before the P0901 code, as it may resolve the underlying issue.
After diagnosing the code(s) recorded by the PCM, the mechanic will take a sequence of diagnostic steps to find the problem and fix it. After taking each step and making each repair, they will clear all codes and retest the system.
Common mistakes when diagnosing the P0901 code
The most common mistakes associated with a P0901 code involve failing to inspect the system closely enough and assuming that the clutch actuator is the cause of the problem. If the actual cause is an open or shorted circuit, the fix could be much simpler and less expensive.
How serious is the P0901 code?
Whether you have a semi-automatic or automatic transmission in your car, it’s important that your vehicle is able to shift at the right times and RPMs. If the clutch actuator is malfunctioning in any way, this can result in a number of problems that could easily put you in danger as you drive your vehicle.
What repairs can fix the P0901 code?
The most common repairs that can fix a P0901 code include:
- Replacing the wiring harness for the clutch actuator
- Reconnecting a loose or disconnected ground
- Replacing a faulty solenoid
- Replacing or reprogramming the PCM or TCM (rare)
Additional comments for consideration regarding the P0901 code
The P0901 code indicates that there is a significant problem in your transmission system that needs to be addressed immediately. In addition to making it impossible to pass an OBD-II emissions test while the Check Engine light is on, this code can result in serious problems for the engine, as well as putting you in dangerous situations while driving.
Need help with a P0901 code?
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