P043E

DTC P043E EVAPORATE EMISSION SYSTEM REFERENCE ORIFICE CLOG UP

DTC SUMMARY

Malfunction Detection Conditions:

HINT: The 0.02 inch orifice is located inside the pump module.

CIRCUIT DESCRIPTION







While the engine is running, if a predetermined condition (closed-loop, etc.) is met, the purge VSV is opened by the ECM and stored fuel vapors in the canister are purged to the intake manifold. The ECM changes the duty cycle ratio of the purge VSV to control purge flow volume.

The purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed into the canister through the vent valve to ensure that the purge flow is maintained when the negative pressure (vacuum) is applied to the canister.

The following two monitors run to confirm appropriate EVAP system operation.

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INSPECTION PROCEDURE

MONITOR DESCRIPTION







5 hours after the ignition switch is turned to OFF, the electric vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

a. P043E: 0.02 inch orifice clogged




In operation B, the vacuum pump creates negative pressure (vacuum) through the 0.02 inch orifice. The EVAP system pressure is then measured by the ECM, using the pressure sensor, to determine the 0.02 inch leak pressure standard. If the pressure is lower than -4.3 kPa (-32.25 mmHg)*, the ECM interprets this as a clog malfunction in the 0.02 inch orifice, and stops the EVAP (Evaporative Emission) system monitor. The ECM then illuminates the MIL and sets the DTC (2 trip detection logic).
*: The threshold varies according to the atmospheric pressure measured in operation A. The value described is based on an atmospheric pressure of 100 kPa (750.1 mmHg): absolute pressure.

b. P043F: 0.02 inch orifice high-flow




In operation B, the vacuum pump creates negative pressure (vacuum) through the 0.02 inch orifice. The EVAP system pressure is then measured by the ECM using the pressure sensor to determine the 0.02 inch leak pressure standard. If the pressure is higher than -1.2 kPa (-9.0 mmHg)*, the ECM interprets this as a high-flow malfunction in the 0.02 inch orifice, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC (2 trip detection logic).
*: The threshold varies according to the atmospheric pressure measured in operation A. The value described is based on a atmospheric pressure of 100 kPa (750.1 mmHg): absolute pressure.

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Monitor Result (Mode 06 Data):

OBD II MONITOR SPECIFICATIONS