most common causes of a power steering problem. Specifically, it can cause a hard steering problem. The PS control module receives the 2 pulse signal from the speedometer board. The speedometer board creates the 2 pulse signal from the speed sensor signal. It tells the PS control module how to regulate the PS rack solenoid. The PS rack solenoid allows a specific amount of pressure in the PS system in accordance with how fast the vehicle is moving. The solenoid is a variable release valve solenoid that is controlled by a wave forming signal via the PS control module. With a loss of the 2 pulse signal at the PS control module, the module goes into safe mode. In safe mode the module outputs a signal to the PS rack solenoid at an equivalent pressure needed at a vehicle speed of 175mph. That amount of pressure at any typical driving speed or even stationary makes it extremely difficult to turn the steering wheel. It’s referred to as a hard steering problem.