System Test
- Start engine, and warm to operating temperature. Check idle speed. If idle speed is excessive, disconnect IACV-AAC valve harness connector. Idle speed should drop.
- If idle speed does not drop, check for battery voltage at IACV-AAC connector terminal "A" (Red wire). If battery voltage is present, go to next step. If battery voltage is not present, check fuses and harness for open circuit.
- Turn ignition off. Disconnect ECM harness connector. Check harness continuity between IACV-AAC connector terminal "B" (Brown/White wire) and ECM (terminal No. 111).
- Continuity should exist. If continuity does not exist, repair wiring as necessary. If harness tests okay, test IACV-AAC valve and inspect ECM connector terminal pins.
NOTE:
On Q45, see ADJUSTMENTS
article for testing and adjustment of fast idle cam. IDLE SPEED SYSTEM INPUT SIGNALS
| Application |
Model Usage |
| A/C Clutch Signal |
Q45 |
| Battery Voltage |
Q45 |
| Closed Throttle Position Switch |
Q45 |
| Crankshaft Position Sensor |
Q45 |
| Engine (Coolant) Temperature |
Q45 |
| Ignition (START) Signal |
Q45 |
| Mass Airflow Sensor |
Q45 |
| Park/Neutral (Inhibitor) Switch |
Q45 |
| Power Steering Pressure Switch |
Q45 |
| Throttle Position Sensor |
Q45 |
| Vehicle Speed Sensor |
Q45 |