Engine Outputs
The Idle Air Control (IAC) solenoid is checked electrically for open and shorts (P0511) and is functionally checked by monitoring the closed loop idle speed correction required to maintain the desired idle rpm. If the proper idle rpm cannot be maintained and the system has a high rpm (+200) or low rpm error (-100) greater than the malfunction threshold, an IAC malfunction is indicated. (P0507, P0506)
IAC CHECK OPERATION
| DTCs | P0507 (functional - overspeed) P0506 (functional - underspeed) |
| Monitor Execution | once per driving cycle |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | 15 seconds |
TYPICAL IAC FUNCTIONAL CHECK ENTRY CONDITIONS
| Entry Condition | Minimum | Maximum |
| Engine Coolant Temp | 150 °F | |
| Time since engine start-up | 30 Seconds | |
| Closed loop fuel | Yes | |
| Throttle Position (at idle, closed throttle, no dashpot) | Closed | Closed |
TYPICAL IAC FUNCTIONAL CHECK MALFUNCTION THRESHOLDS
| For underspeed error: Actual rpm 100 rpm below target, closed-loop IAC correction > 1 lb/min For overspeed error: Actual rpm 200 rpm above target, closed-loop IAC correction <.2 lb/min |
The PCM monitors the "smart" driver fault status bit that indicates either an open circuit, short to power or short to ground.
INJECTOR CHECK OPERATION
| DTCs | P0201 through P0210 (opens/shorts) |
| Monitor Execution | Continuous within entry conditions |
| Monitor Sequence | None |
| Monitoring Duration | 5 seconds |
TYPICAL INJECTOR CIRCUIT CHECK ENTRY CONDITIONS
| Entry Condition | Minimum | Maximum |
| Battery Voltage | 11.0 volts |