Code 0704

The EVAP control system pressure sensor is installed in the purge line. The sensor detects the pressure inside the purge line and modifies the voltage signal sent from the ECM. The modified signal will then be returned to the ECM as an input voltage signal. As the pressure increases, the voltage rises. The EVAP control system pressure sensor is not directly used to control the engine system. It is used only for on-board diagnosis.







DIAGNOSTIC CHART




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
CONSULT
1) Start engine and warm it up sufficiently.
2) Turn ignition switch "OFF" and wait for at least 5 seconds.
3) Turn ignition switch "ON".
4) Select "DATA MONITOR" mode with CONSULT.
5) Wait for at least 12 seconds.

OR

GST
1) Start engine and warm it up sufficiently.
2) Turn ignition switch "OFF" and wait for at least 5 seconds.
3) Turn ignition switch "ON" and wait for at least 12 seconds.
4) Select "MODE 3" with GST.

OR

NO TOOLS
1) Start engine and warm it up sufficiently.
2) Turn ignition switch "OFF" and wait for at least 5 seconds.
3) Turn ignition switch "ON" and wait for at least 12 seconds.
4) Turn ignition switch "OFF", wait for at least 5 seconds and then turn "ON".
5) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
COMPONENT INSPECTION
EVAP control system pressure sensor
1. Remove EVAP control system pressure sensor from bracket with its harness connector connected.
2. Remove hose from EVAP control system pressure sensor.




3. Apply vacuum and pressure to EVAP control system pressure sensor with pump as shown in figure.
4. Check output voltage between terminal (2) and engine ground.




5. If NG, replace EVAP control system pressure sensor.




WIRING DIAGRAM