DTC 0704

COMPONENT DESCRIPTION
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.




CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.




ECM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values, and are measured between each terminal and (25) (ECCS ground) with a voltmeter.




ON BOARD DIAGNOSTIC LOGIC

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
With Consult
(1) Start engine and warm it up sufficiently.
(2) Check that tank fuel temperature is above 0°C (32°F).
(3) Turn ignition switch "OFF" and wait at least 5 seconds.
(4) Turn ignition switch "ON".
(5) Select "DATA MONITOR" mode with CONSULT.
(6) Wait at least 3 seconds.

OR

With GST
(1) Start engine and warm it up sufficiently
(2) Check that voltage between ECM terminal (52) and ground is less than 4.2V.
(3) Turn ignition switch "OFF" and wait at least 5 seconds.
(4) Turn ignition switch "ON" and wait at least 3 seconds.
(5) Select "MODE 7" with GST.

OR

No Tools
(1) Start engine and warm it up sufficiently.
(2) Check that voltage between ECM terminal (52) and ground is less than 4.2V.
(3) Turn ignition switch "OFF" and wait at least 5 seconds.
(4) Turn ignition switch "ON" and wait at least 3 seconds.
(5) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
(6) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.

EC-PRE/SE-01 Evaporative Emission (EVAP) Control System Pressure Sensor (DTC: P0450):

WIRING DIAGRAM







DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION
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 Q2 and engine ground.

Pressure (Relative to atmospheric pressure) / Voltage (V)
+4.O kPa (+3O mmHg, +1.18 inHg) / Approximately 4.6
-9.3 kPa (-70 mmHg, -2.76 inHg) / Approximately 0.5

CAUTION: Always calibrate the vacuum pump gauge when using it.

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