Test Ff: Step 10

10) Check For PSPS Always Closed Compared to Hydraulic Pressure With Engine Running  At this point, there are only 2 possible causes for the original KOER Code 52. They are a PSPS switch that will not open, or low available hydraulic pressure. Turn key off and wait 10 seconds. Substitute original switch with a known good PSPS switch. Perform KOER Self-Test and turn steering wheel at least 1/2 turn after engine ID code. If Code 52 is still present, check power steering system for hydraulic pressure. If Code 52 is not present, replace original PSPS switch. Service other codes if necessary.