P0635 Power Steering Control Circuit
OBD-II Trouble Code Technical Description
Power Steering Control Circuit
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from Saturn, Renault, Dodge, Ford, Nissan, Mercedes, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration.
OBD-II trouble codes P0635, P0636, and P0637 are associated with the power steering control circuit.
When the Power Control Module (PCM) detects improper signals within the power steering control circuit code P0635 will be set and the check engine light will be illuminated.
The purpose of the power steering control circuit is to provide the appropriate voltage to various power steering components. The PCM monitors voltage signals from the power steering controller, sensors and switches. These components provide the proper fluid pressure within the power steering system. This process is essential to prevent damage to power steering components. The power steering control circuit facilitates the power steering system to adapt to various driving conditions and prevent Stiff or erratic steering. This circuit alerts the PCM that possible issues exist that require immediate attention.
An electric power steering motor:
What is the severity of this DTC?
The severity of this code can vary tremendously from just an illuminated check engine light on a vehicle that operates normally to a stiff or erratic steering issue. Steering problems can become a safety issue when not given immediate attention.
What are some of the symptoms of the code?
Symptoms of a P0635 trouble code may include:
What are some of the common causes of the code?
Causes for this P0635 code may include:
What are some P0635 troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB’s) for the specific vehicle by year, model and power plant. In some circumstances this can save a lot of time in the long run by pointing you in the right direction.
The second step is to check the power steering fluid level and look for possible leaks that would have a negative impact on the pressure supplied to the power steering controller and associated components. The proper fluid pressure plays a key role in the function of this circuit. Then locate all of the components within this circuit and perform a thorough visual inspection to check the associated wiring for obvious defects such as scraping, rubbing, bare wires, or burn spots. Next is to check the connectors for security, corrosion and damaged pins. This process must include the power steering controller, associated sensors, switches and the PCM. The condition of the Controller Area Network (CAN) is essential to this troubleshooting process because a damaged wiring harness makes it very difficult to pinpoint defective components.
Advanced Steps
The advanced steps become very vehicle specific and require the appropriate advanced equipment to perform accurately. These procedures require a digital multi meter and the specific technical references for the vehicle. Voltage requirements will vary based on the specific year and model of the vehicle.
Voltage Checks
Specific troubleshooting guidelines must be referenced to determine the voltage ranges required within the power steering control circuit. Based on the configuration, several power steering components are incorporated. Power steering controllers, pressure switches and position sensors require different voltages to function properly based on the specific vehicle involved.
If this process identifies the absence of a power source or ground, continuity testing may be required to check the integrity of the wiring, connectors and other components. Continuity tests should always be performed with the power removed from the circuit and the normal readings for wiring and connections should be 0 ohms of resistance. Resistance or no continuity is an indication of faulty wiring that is open or shorted and must be repaired or replaced.
What are some common repairs for this code?
Note: Code P0635 will often prevent a control module from communicating properly, other trouble codes may be triggered. CAN issues can be very difficult to pinpoint causing a misdiagnosis in some circumstances.
Hopefully, the information in this article has been helpful to point you in the right direction to correct the problem with your power steering circuit fault code. This article is strictly informational and the specific technical data and service bulletins for your vehicle should always take priority.
Need help?
Let us fix your problem. You are most welcome our diagnosis experts have in most cases the knowledge and skills to find the cause of the error code p0635 and to solve the problems.
Make an appointment for diagnosis
"Delete Error Code Permanently, Disable DTC Error Code Function for p0635 in the ECU"
In extreme cases, we even have the option to permanently remove the specific DTC p0635 and disable the function of the specific error code in the ECU. All other fault code functions will then continue to work to protect the engine. This is different from clearing an error code with a diagnostic device. We have the option to permanently remove the function of the specific error code, so that it never comes back. Also emergency running that occurs on the specific error code can be solved in most cases.
Of course we prefer to first try to solve the cause of the error code, but sometimes the only solution is to permanently disable the DTC function of p0635.
