System Check (MPV)
- Ensure engine is at ambient temperature. Connect scan tool. Using PID/DATA monitor and record function, select ECT, IAC V and RPM PIDs. Start engine.
- Engine speed should decrease as engine reaches operating temperature. If idle speed decreases, go to next step. If engine speed does not decrease, check ECT sensor, IAC valve and wiring.
- Allow engine to warm to operating temperature. Check for DTC P0506, P0507 and P1504. If no DTCs are present, go to next step. If any DTCs are present, diagnose and repair as necessary.
- Using scan tool, select SIMULATION TEST. Change duty cycle of IAC valve to 100 percent. If idle speed increases, go to next step. If idle speed does not increase, check IAC valve passages and wiring.
- Using scan tool PID/DATA monitor and record function, select A/C SW, ALTF, IAC V, PSP SW, RPM and RPM DES PIDs. Ensure idle speed stays in specification when accessories are operated. See IDLE SPECIFICATIONS
table. If idle speed is okay, check is complete. If idle speed is not okay, check suspect component and circuit.
IDLE SPECIFICATIONS
| Condition |
Idle Speed |
| No Load |
700-800 |
| All Accessories On |
700-800 |
| Power Steering Operating |
700-800 |
| A/C On |
800-900 |