On Board Diagnosis Logic

NOTE: If DTC P0442 is displayed with P1448, perform trouble diagnosis for DTC P1448 first. (See DTC P1448 EVAP CANISTER VENT CONTROL VALVE .)

This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum.

If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve, under the following Vacuum test conditions.

The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this occurs, the EVAP canister purge volume control solenoid valve will be closed.

Fig 1: Identifying EVAP Control System

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: DTC Detecting Condition And Possible Causes

Courtesy of NISSAN MOTOR CO., U.S.A.

CAUTION:

Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the MIL may come on.
If the fuel filler cap is not tightened properly, the MIL may come on.
Use only a genuine NISSAN rubber tube as a replacement.