Power Steering Pressure Switch

NOTE: Begin this test with engine idling at operating temperature and wheels pointed straight ahead.


1. Probe ECM terminal M2-7 (blue wire) with positive voltmeter lead and ground negative lead. Reading should be near battery voltage.
2. While observing the meter, turn steering wheel for a sharp turn in either direction. When the power steering load increases to the point where it will affect idle quality, the switch will close and cause the meter reading to drop to less than one volt. This result indicates that switch and circuit are functioning properly.
3. If testing indicates problems, check the wiring circuit and test the switch as described in step 4 below.
4. To test the switch itself, remove harness connector at switch and connect ohmmeter leads across switch terminals. Meter should indicate an open circuit with steering directed forward and continuity when fluid pressure rises in response to a sharp turn in either direction.