PO551 Power Steering Switch
 

The engine light came on with a PO551 error code which indicates a power steering switch problem. I have a 2001 PT -it it is running and steering fine. I have seen that a few other people have the same problem. Anybody seen this before? How did you fix it? Thanks!

RE: PO551 Power Steering Switch
 

HI
Yes seen it before and to fix it I replaced the switchon the steering rack.

RE: PO551 Power Steering Switch
 

Roger and out the door I go for the switch. I will let you know. Thanks

RE: PO551 Power Steering Switch
 

The new $27 switch is on. So far so good but I didnt drive the car too much. Tomorrow will be the test!

RE: PO551 Power Steering Switch
 

ok it worked! Now can some one tell me exactly why. From what I have read it is a normally open switch untill it reaches 500 psi. There are only two wires going to the switch. If it was as simple as that- disconnecting the plug would have cause no errors. There must be more to the switch than just a single pole switch???

RE: PO551 Power Steering Switch
 

Hi
Happy for you it fix your fault.
When power steering pump pressure exceeds 2758 kPa (400 psi), the switch is open. The PCM increases idle air flow through the IAC motor to prevent engine stalling. The PCM sends 12 volts through a resister to the sensor circuit to ground. When pump pressure is low, the switch is closed.
Hope this helps you understand why.