Humidity Method
CAUTION:
Never apply water directly onto suspected component. Indirectly change the temperature and humidity by spraying water on front of radiator.
If humidity or moisture are suspected of causing an intermittent failure, spray water on the radiator to increase humidity in the engine compartment. Check if a malfunction occurs by monitoring the suspected circuit or component with a DVOM.
If a vehicle is subject to water leakage, the admitted water may contaminate the ECU. When testing a vehicle where water leakage has occurred, carefully inspect the ECU terminals for corrosion. Repair or replace the ECU connectors as required.