Humidity Method
CAUTION:
DO NOT apply water directly to suspect component. Change temperature and humidity by lightly spraying water to front of radiator.
If humidity or moisture is suspected of causing intermittent failure, lightly spray water to the front of warm/hot radiator to increase humidity in the engine compartment. Check for malfunction by monitoring suspect circuit or component with a DVOM.
If vehicle has interior water leakage, the admitted water may contaminate ECU. When testing a vehicle that has interior water leakage, carefully inspect ECU terminals for corrosion. Repair or replace ECU and connectors if necessary. Repair interior water leakage problem.