Idle Speed/Throttle Actuator - Electronic: Testing and Inspection
SYSTEM OPERATI0NAL CHECKISC System Check:
NOTE: Start this check with engine cold (coolant temperature below 68°F, 20°C).
1. Connect a tachometer to diagnosis connector terminal "IG-." When using an externally powered tachometer, connect it to the power connector (Blue: 1-pin).
CAUTION: Grounding the power connector (Blue: 1-pin) will blow the 20A wiper fuse. To avoid possible component damage, be extremely careful when making connections to the diagnosis connector.
2. Connect Mazda System Selector (SST #49 B019 9A0) or aftermarket equivalent to diagnosis connector and set test switch to "SELF TEST." If tool is not available, connect a jumper wire between diagnosis connector terminals "TEN" and "GND."
3. Start engine and verify that rpm gradually decreases as engine warms up.
4. If not as specified, check ISC valve, air valve, cooling system operation, and related wiring and connections. Repair as needed.
5. Remove System Selector or jumper wire.
VALVE INSPECTION
Idle Speed Control (ISC) Valve:
1. Warm up engine and run at idle.
2. Remove connector (Black: 2-pin). Check for "click" sound and engine speed increase to approximately 1200 rpm.
3. If engine speed does not increase and no other problem is detected, replace ISC valve.
RESISTANCE CHECK
Idle Speed Control (ISC) Valve Testing:
1. Disconnect ISC valve connector.
2. Check resistance across valve terminals. It should be 11 - 13 ohms at 20°C (68°F).
3. If not as specified, replace valve.