C0000 – ISO/SAE Reserved / Vehicle speed information circuit malfunction (Chevy, GM)

By Akindayini Temiloluwa (Contact Me)
Last Updated 2022-04-20
Automotive mechanic

Table of Contents

1. What Does Code C0000 Mean?
2. Where is the C0000 sensor located?
3. What are the common causes of code C0000?
4. What are the symptoms of code C0000?
5. Codes Related to C0000
6. Get Help with C0000

What Does Code C0000 Mean?

NOTE: C0000 is a strange code.  The C0XXX format suggests by SAE standards it is a generic code yet our research only shows C0000 associated with Chevy / General Motors vehicles.  Also numerous sources list B0000 with same definition “Vehicle Speed Information Circuit Malfunction.”  It is very possible if you see this code that you have a incompatible or faulty OBD2 scan tool as described in our article about “Nonsense Codes.”  While this article with cover the definition “Vehicle Speed Information Circuit Malfunction” for C0000, you should try to double check this code with a different and ideally manufacturer specific scan tool.

On some GM vehicles (Chevy in particular) the diagnostic trouble code C0000 has the definition of “Vehicle Speed Information Circuit Malfunction.”  The steering control modules are designed to receive signals from the PCM via the VSS circuit (Vehicle speed signal circuit ).  The data from these modules are compared and used to determine how much steering help is required.  The PSCM offers more assistance at a lower speed, while at a higher speed, less assistance is given. 

When you notice the C0000 trouble code, the first step in dealing with the trouble code is to check for other PCM codes that may accompany the C0000. On many occasions, where there is no other PCM-related codes, the issue may be traced to the faulty wiring from the PCM to PSCM. 

The code gets triggered when the PSCM fails to give the driver the steering assistance needed.  This is a serious problem that needs to be treated urgently. The code will be accompanied with an ABS warning light and check engine light.

Where is the C0000 sensor located?

Since the main cause of this code on GM vehicles is the PSCM, it would be best to check out the PSCM, which is located at the steering gear or steering column. Check to see if the PSCM is working correctly. Also, check the electrical wiring connected to the PSCM. If the PSCM is not working correctly, it would be best to replace it ideally with a GM-certified version.

If the PSCM does not have any fault, you can go ahead to check other components that work with the PSCM, like the speed sensors and electrical circuits. You can also check the steering fluid to make sure the vehicle’s symptoms are not a result of low steering fluid.

What are the common causes of code C0000?

NOTE:  The cause may be a bad or faulty OBD2 scanner, and the definition given in this article is not applicable.

• Damaged Power Steering Control Module (PSCM)
• A bad electrical connection in the PSCM circuit
• Faulty speed sensor
• Bad wiring
• Open or short PSCM harness
• Malfunctioned speed sensors

What are the symptoms of code C0000?

These are symptoms of the C0000 code in your GM / Chevy vehicle. It is important to know that these symptoms are not limited to this code. These symptoms could result from other problems the car may be facing, like low steering fluid and more. This is why it is important to make a proper diagnosis.

• The check engine light will be triggered
• Loss of steering power, that is, the steering will become stiffer and more difficult to control.
• Anti-lock Brake System (ABS) warning light
• Dwindling turning radius
• The speedometer begins to malfunction

It is also important to know that there might be no symptoms. As we have said earlier, using the wrong scanner or a faulty one may set the C0000 code when there is nothing relating to the code happening to the vehicle.

Codes Related to C0000

P0500 Code – This is also known as the vehicle speed sensor (VSS), and it is a common code error that may come with this code. The code has to do with a faulty speed sensor detected by the ECM due to inaccurate speed data from the speed sensor.

U0131 code – This code also has to do with the PSCM. This code will come up when there is a loss of communication between the Power Steering Control Module (PSCM) and the Engine Control Unit.

B0000 code – This code comes up with the same definition and association with GM / Chevy.

It is also important to note that the C0000 code might not have any underlying codes that may come up with it. This is because it may be a result of a bad OBDII scanner. It could also result from the code being a no-fault code.

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