Power Steering Pressure (PSP) Switch System Test: Q45
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Infiniti QX4, 2003 Infiniti Q45, 2003 Infiniti M45, 2003 Infiniti I35, and 2003 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition switch to OFF position. Loosen and retighten engine ground screws. See Fig 1. Go to next step.
- Disconnect PSP switch harness connector. See Fig 2. Turn ignition switch to ON position. Check voltage between ground and PSP switch terminal No. 1. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Voltage should be about 5 volts. If voltage is as specified, go to step 4. If voltage is not as specified, go to next step.
- Check the following:
- Harness connectors F5 and E315.
- Harness for open or short between ECM and power steering pressure switch.
Repair open circuit or short to ground or short to power in harness or connectors.
- Turn ignition switch to OFF position. Check harness continuity between PSP switch terminal No. 3 and engine ground. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. See Fig 1. Continuity should exist. Also check harness for short to power. If no problem is found, go to step 6. If problem is found, go to next step.
- Check the following:
- Harness connectors F5 and E315.
- Joint connector-30.
- Harness for open or short between PSP switch an ECM.
Repair open circuit or short to power in harness or connectors.
- Disconnect ECM harness connector. Check harness continuity between ECM terminal No. 118 and PSP switch terminal No. 2. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Continuity should exist. Also check harness for short to ground and short to power. If no problem is found, go to step 8. If problem is found, go to next step.
- Check the following:
- Harness connectors F5 and E315.
- Harness for open or short between ECM and power steering pressure switch.
Repair open circuit or short to ground or short to power in harness or connectors.
- Check PSP switch. Reconnect all disconnected harness connectors. Start engine and let it idle. Check voltage between ECM terminal No. 118 and ground under specified conditions. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. See POWER STEERING PRESSURE SWITCH VOLTAGE TEST table. If results are as specified, go to next step. If results are not as specified, replace PSP switch.
- No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.