Code 0704

COMPONENT DESCRIPTION
The EVAP control system pressure sensor detects pressure in the purge line The sensor output voltage to the ECM increases as pressure increases. The EVAP control system pressure sensor is not used to control the engine system. It is used only for on board diagnosis.




CONSULT Reference Value in Data Monitor Mode
Specification data are reference values.




ECM Terminals and Reference Value
Specification data are reference values and are measured between each terminal and 43 (ECM ground).




ON BOARD DIAGNOSIS LOGIC

DTC CONFIRMATION PROCEDURE

NOTE: If "DTC Confirmation Procedure" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.

TESTING CONDITION:
- Always perform test at a temperature above 5 °C (41 °F).
- Before performing the following procedure, confirm battery voltage is more than 10 V at idle.




With CONSULT
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 5 seconds.
3. Turn ignition switch "ON".
4. Select "DATA MONITOR" mode with CONSULT.
5. Make sure that "TANK F/TEMP SE" is more than 0 °C (32 °F).
6. Start engine and wait at least 20 seconds.
7. If 1st trip DTC is detected, go to "Diagnostic Procedure".

With GST
1. Start engine and warm it up to normal operating temperature.
2. Check that voltage between ECM terminal 63 (Tank fuel temperature sensor signal) and ground is less than 4.2 V.
3. Turn ignition switch "OFF" and wait at least 5 seconds.
4. Start engine and wait at least 20 seconds.
5. Select "MODE 7" with GST.
6. If 1st trip DTC is detected, go to "Diagnostic Procedure".

Without Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Check that voltage between ECM terminal 63 (Tank fuel temperature sensor signal) and ground is less than 4.2 V.
3. Turn ignition switch "OFF" and wait at least 5 seconds.
4. Start engine and wait at least 20 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.
7. If 1st trip DTC is detected, go to "Diagnostic Procedure".







WIRING DIAGRAM

1 CHECK RUBBER TUBE CONNECTED TO THE SENSOR:

2 RETIGHTEN GROUND SCREWS:

3 CHECK HARNESS CONNECTOR:

4 CHECK POWER SUPPLY:

5 DETECT MALFUNCTIONING PART:

6 CHECK GROUND CIRCUIT:

7 DETECT MALFUNCTIONING PART:

CHECK INPUT SIGNAL CIRCUIT:

9 DETECT MALFUNCTIONING PART:

10 CHECK EVAP CANISTER PURGE VOLUME CONTROL VALVE:

11 CHECK EVAP CANISTER VENT CONTROL VALVE:

12 CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR:

13 CHECK RUBBER TUBE FOR CLOGGING:

14 CHECK IF EVAP CANISTER SATURATED WITH WATER:

15 CHECK EVAP CANISTER:

16 DETECT MALFUNCTIONING PART:

17 CHECK SHIELD CIRCUIT:

18 DETECT MALFUNCTIONING PART:

19 CHECK INTERMITTENT INCIDENT:

DIAGNOSTIC PROCEDURE




COMPONENT INSPECTION
1. Remove EVAP control system pressure sensor with its harness connector connected.
2. Remove hose from EVAP control system pressure sensor.
3. Use pump to apply vacuum and pressure to EVAP control system pressure sensor as shown in image.




4. Check output voltage between ECM terminal 67 and engine ground.

CAUTION:
- Always calibrate the vacuum pump gauge when using it.
- Do not apply below -20 kPa (-150 mmHg, -5.91 inHg) or over 20 kPa (150 mmHg, 5.91 inHg) of pressure.

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