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" (Gray wire on G20, Green/Yellow wire on J30, Red wire on Q45). 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" (Light Blue wire on G20, Blue wire on J30, Brown/White wire on Q45) and ECM. (Terminal 113 on G20, terminal 4 on J30 or terminal 111 on Q45). Continuity should exist. If continuity does not exist, repair wire as necessary.
- If harness tests okay, test IACV-AAC valve and inspect ECM connector terminal pins.
NOTE:
On Q45, see ADJUSTMENTS
article in the ENGINE PERFORMANCE Section for testing and adjustment of fast idle cam.
IDLE SPEED SYSTEM INPUT SIGNALS
| Application |
Model Usage |
| A/C Clutch Signal |
G20,
J30 &
Q45 |
| Mass Airflow Sensor |
Q45 |
| Battery Voltage |
G20, J30 & Q45 |
| Crankshaft Position Sensor |
G20, J30 & Q45 |
| Engine (Coolant) Temperature |
G20, J30 & Q45 |
| Ignition (START) Signal |
G20, J30 & Q45 |
| Neutral Switch |
G20 |
| Park/Neutral (Inhibitor) Switch |
G20,
J30 &
Q45 |
| Power Steering Pressure Switch |
G20, J30 & Q45 |
| Throttle Position Sensor |
G20, J30 & Q45 |
| Closed Throttle Position Switch |
J30 & Q45 |
| Vehicle Speed Sensor |
G20, J30 &
Q45 |