P1455

DTC P1455 VAPOR REDUCING FUEL TANK SYSTEM MALFUNCTION

CIRCUIT DESCRIPTION

DTC Detection Condition:

Using the heated oxygen sensor and VSV for purge flow switching valve (bypass VSV), the ECM detects fuel leaks from inside a bladder tank the fuel tank.

Based on signals from the heated oxygen sensor while the VSV for purge flow switching valve is ON, the ECM judges if fuel is leaked from the bladder tank or not.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Monitor Result (Mode 06 Data):

The ECM detects leakage of evaporative emissions from the bladder membrane by using the heated oxygen sensor and VSV for the purge switching valve. By opening the EVAP VSV and then closing the VSV for purge flow switching valve, air in the outer tank is drawn into the intake manifold.

The ECM checks concentration of hydrocarbon (HC) molecules in the air drawn from the bladder membrane area. Also, the ECM checks the sensor output before and after closing the VSV for purge switching valve. If there is change in the HC concentration when the VSV is opened or closed, the ECM will conclude that the bladder membrane is leaking. The ECM will illuminates the MIL and a DTC is set.

Step 1 - 2:

INSPECTION PROCEDURE

HINT: Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine condition when malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.