Engine Controls - Confirmation Of DTC P0440

Classification:
EC97-048

Reference:
NTB98-017

Date:
March 15, 1998

Subject:
PERFORMING CONSULT DTC CONFIRMATION FOR P0440 ON 1998 MY VEHICLES

APPLIED VEHICLES:
All 1998 Pathfinder (R50)
All 1998 Maxima (A32)
All 1998 Quest (V40)
All 1998 240SX (S14)
All 1998 Altima (L30)
All 1998 Sentra/200SX (B14)
All 1998 Frontier (D22)

SERVICE INFORMATION





When performing CONSULT DTC confirmation for P0440 (EVAP system small leak) using the UEOBD98 CONSULT card on 1998 MY vehicles, a message of "CAN NOT BE DIAGNOSED" may appear on the screen (see Figure 1). The service procedure below has been developed to eliminate this incident.

SERVICE PROCEDURE

If fuel vapor pressure is present in the fuel tank during testing, the test will stop and the "CAN NOT BE DIAGNOSED" message will display. Use the following procedure to perform DTC confirmation for P0440 on 1998 MY vehicles.

1. Loosen the fuel filler cap to relieve vapor pressure in the fuel tank before starting DTC confirmation procedure.

2. Make sure the following conditions are met before starting the test:

^ Fuel level is less than 3/4 full (it is preferable that the fuel level is low)

^ Vehicle is placed on level ground

^ Ambient temperature is 5 to 30°C (41 to 86°F)

^ Engine coolant temperature is 0 to 70°C (32 to 158°F)

^ Intake air temperature is 5 to 60°C (41 to 140°F)





3. Connect CONSULT and use the step-by-step procedure in Figure 2 to perform the test. Make sure the OBD98 card is loaded into CONSULT.

NOTE:
If the results of the test are not OK, check the DTC P0440 section of the appropriate service manual for the service procedure.