Power Steering Pressure Switch Circuit Check: Aerio
- If scan tool is not available, go to next step. Turn ignition off. Connect scan tool to Data Link Connector (DLC). DLC is located under left side of instrument panel. Start engine. On scan tool, select DATA LIST and observe POWER STEERING PRESSURE SWITCH parameter. With engine running and steering wheel in straight ahead position, parameter should read OFF and voltage should be 10-14 volts. With engine running and steering wheel turned right or left, parameter should read ON and voltage should be 0-1 volts. If parameter and voltage readings are as specified, power steering signal circuit is okay. If parameter and voltage readings are not as specified, go to step 3 .
- Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM connector C46 terminal No. 17 (Yellow wire). See Figure . With engine running and steering wheel in straight ahead position, voltage should be 10-14 volts. With engine running and steering wheel turned right or left, voltage should be 0-1 volts. If parameter and voltage readings are as specified, power steering signal circuit is okay. If parameter and voltage readings are not as specified, go to next step.
- Turn ignition off. Disconnect Power Steering Pressure (PSP) switch harness connector. Turn ignition on. Measure voltage between ground and PSP switch harness connector. If voltage reading is 10-14 volts, PSP switch or power steering is malfunctioning. Repair or replace as necessary. If voltage reading is not as specified, go to next step.
- Check for open or short to ground in Yellow wire between PSP switch and ECM. See WIRING DIAGRAMS article. Also, check for poor terminal connections at PSP switch and ECM. If problem is found, repair as necessary. After repair, retest system. If no problem with wiring or switch is found, substitute ECM with known good unit and retest system.