EVAP Leak Monitor Small Leak Detected (OBD II)

Name of Code:
Evap System Small Leak

When Monitored:
See DRB III

Set Condition:
See DRB III

Theory of Operation:
The first portion of the test determines whether or not a line is pinched in the system. If the pump rate falls to zero too rapidly, the PCM determines that there is not enough space to pressurize, this indicates a possible pinched line. If there is a leak present in the EVAP system, the cycle rate falls to a rate proportional to the size of the leak. By monitoring the cycle rate of the pump, the PCM is able to calculate the size of the leak.

Possible causes:
- A leak in the evaporative system between 0.040" and 0.080"
- Leak detection pump failure