DTC P1456 '01 Model: EVAP Control System Leakage (fuel tank system): Notes

NOTE: The fuel system is designed to allow specified maximum vacuum and pressure conditions. Do not deviate from the vacuum and pressure tests as indicated in these procedures. Excessive pressure/vacuum would damage the EVAP components or cause eventual fuel tank failure

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg A973X-041-XXXXX

NOTE: If DTC P0461 is stored at the same time as DTC P1456, troubleshoot DTC P0461 first, then recheck for DTC P1456.

This is a two trip code; once cleared, it cannot be reproduced in one trip. Also, certain specific driving and ambient conditions must occur before the PCM will complete the system checks. Additional test drives may still not meet the specific conditions needed to reproduce the code.

Follow these troubleshooting procedures carefully to ensure the integrity of the system and to confirm the cause of the problem or code.

NOTE: Fresh fuel has a higher volatility that will create greater pressure/vacuum. The optimum condition for testing is fresh fuel and less than a full tank of gas. If possible, to assist in leak detection, add 1 gallon of fresh fuel to the tank (as long as it will not fill the tank), just before starting these procedures.