During an ASM test, if the EIS indicates a "Sample Dilution," what action should the technician take?

In the context of an ASM (Acceleration Simulation Mode) test, a "Sample Dilution" indication from the Emission Inspection System (EIS) suggests that there may be a compromise in the exhaust sample being taken, leading to inaccurate readings. The correct action in this scenario is to look for a kink in the EIS intake sample hose. A kink in the hose can restrict airflow or cause improper sampling of the exhaust gases, which can dilute the sample and result in misleading emissions data.

Proper airflow and an unobstructed path are critical for accurate emissions measurement. If the hose is kinked or otherwise obstructed, it would prevent the EIS from capturing a representative sample of the exhaust, leading to the dilution reading.

Other potential actions may address symptoms or secondary issues, but identifying and rectifying any physical obstruction along the sample intake is the most direct and effective way to ensure accurate sampling and testing results.