Test 1
- Turn ignition off. Disconnect self-test jumper. Connect tachometer and start engine. Read engine RPM. Engine RPM should be 775 to 825. If reading in correct go to next step. If not, go to step 3).
- Turn ignition off. Disconnect engine coolant temperature switch. Start engine. Engine RPM should be 1175 to 1225. If reading is correct, ICS system is working properly, go to TEST 6. If not, go to next step.
- Engine Preparation
Run vehicle for 2 minutes at 2000 RPM. Verify water temperature was above 128°F (53°C) during self-test (upper radiator hose hot and pressurized). If reading is correct go to next step. If not, repair engine cooling system.
- ECT Switch Check
Disconnect vehicle harness from Engine Coolant Temperature (ECT) switch. Check contacts of ECT switch. Contact should be closed above 128°F (53°C). Measure resistance. If resistance is 5 ohms or less go to next step. If resistance is more than 5 ohms, replace ECT switch and retest.
- Continuity Check
Disconnect vehicle harness from the ISC-E processor. Check circuits 354 and 60 for continuity. Measure resistance. If resistance is 5 ohms or less go to next step. If resistance is more than 5 ohms, service or replace circuit and retest.
- Short to Ground
Connect one lead of VOM to circuit 354 and the other to engine ground. Measure resistance. If resistance is more than 1000 ohms, replace ISC-E processor and retest. If resistance is 1000 ohms or less, repair or replace circuit.