Circuit Description
WARNING: This page is about a different car, the 2000 Isuzu Rodeo and 2000 Isuzu Amigo. However, it is still accessible from the selected car via links, so may be relevant.
Evaporative (EVAP) emission system is checked by applying vacuum to the EVAP system and monitoring for a vacuum leak. PCM monitors vacuum level via fuel tank pressure sensor signal. When appropriate, EVAP canister purge valve and EVAP canister vent solenoid are turned on, allowing engine to draw a small vacuum on the entire evaporative emission system. After the desired vacuum level has been achieved, EVAP canister purge valve is turned off, sealing the EVAP system. If a large leak is detected, DTC P0440 will be set under the following conditions.
Conditions required to set DTC are:
- DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134 and P1133 are not set.
- BARO is greater than 72.3 kPa.
- Start-up IAT and ECT is between 38.5-90.5°F (3.5-32.5°C).
- Difference between ECT and IAT at start up is less than 12.2°F (6.75°C).
- Vehicle speed is less than 60 MPH.
- Fuel tank level sensor reads 10-90 percent.
- Fuel counts vary by less than 15 counts in .125 second time frame.
- Maximum engine run time is at least 540 seconds (9 minutes).
- Difference between the actual fuel tank pressure and the expected fuel tank pressure is less than the PCM's expectations.
The listed conditions are met, and the following is met once:
- EVAP system is unable to maintain vacuum, depending upon amount of fuel in fuel tank, during diagnostic test.