Test 1 - Rpm Check
- Turn ignition off. Disconnect self-test jumper. Connect tachometer and start engine. Note engine RPM. Engine RPM should be 775 to 825. Proceed to next step if engine RPM is within specification. 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 reading is incorrect, proceed 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. If reading is correct, proceed to next step. Repair engine cooling system if temperature reading is incorrect.
- ECT Switch Check
Disconnect vehicle harness from Engine Coolant Temperature (ECT) switch. Check ECT switch contacts. Contact should be closed above 128°F (53°C). Measure resistance between contacts. Proceed to next step if resistance is 5 ohms or less. Replace ECT switch if resistance exceeds 5 ohms. Perform test after repairs.
- Continuity Check
Disconnect vehicle harness from the ISC-E processor. Check circuits 354 and 60 for continuity. Measure resistance. Proceed to next step if resistance is 5 ohms or less. Service or replace circuit if resistance exceeds 5 ohms. Perform test after repairs.
- Short to Ground
Connect one lead of VOM to circuit 354 and the other to engine ground. Measure resistance. If resistance exceeds 1000 ohms, replace ISC-E processor. Repair or replace circuit if resistance is 1000 ohms or less. Perform test after repairs.