With Generic Scan Tool

COMPONENT DESCRIPTION
The absolute pressure sensor is connected to the MAP/BARO switch solenoid valve by a hose. The sensor detects ambient barometric pressure and intake manifold pressure respectively, and modifies the voltage signal received from the ECM. The modified signal will then be returned to the ECM. As the pressure increases, the voltage rises.






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 (26) (ECCS ground).






ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
Perform "Procedure for malfunction A" first. If the 1st trip DTC cannot be confirmed, perform "Procedure for malfunction B". If the 1st trip DTC is not confirmed on "Procedure for malfunction B", perform "Procedure for malfunction C".



Procedure for malfunction A

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.


With Generic Scan Tool
(1) Turn ignition switch "ON" and wait at least 10 seconds.
(2) Select "MODE 7" with GST.


Procedure for malfunction B

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.


With Generic Scan Tool
(1) Start engine and warm it up to normal operating temperature.
(2) Turn ignition switch "OFF" and wait at least 5 seconds.
(3) Start engine.
(4) Let engine idle and wait at least 15 seconds.
(5) Select "MODE 7" with GST.


Procedure for malfunction C

CAUTION: Always drive vehicle at a safe speed.

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.


OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the front heated oxygen sensor circuit. During this check, a 1st trip DTC might not be confirmed.






With Generic Scan Tool
(1) Turn ignition switch "ON".
(2) Select "MAP" in "MODE 1" with GST.
(3) Make sure that the pressure of "MAP" is more than 46 kPa (0.47 kg/sq.cm, 6.7 psi).






Circuit Connectors






Electrical Diagrams


DIAGNOSTIC PROCEDURE
If the trouble is duplicated after "Procedure for malfunction A or B", perform "Procedure A". If the trouble is duplicated after "Procedure for malfunction C", perform "Procedure B".









Procedure A






Procedure B



COMPONENT INSPECTION








Absolute pressure sensor
1. Remove absolute pressure sensor from bracket with its harness connector connected.
2. Remove hose from absolute pressure sensor.
3. Turn ignition switch "ON".
4. Apply vacuum and barometric pressure to absolute pressure sensor as shown in figure.
5. Check output voltage between ECM terminal (61) and (25) (ECM ground).

CAUTION:
- Always calibrate the vacuum pump gauge when using it.
- Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) and over 101.3 kPa (760 mmHg, 29.92 inHg) of pressure.

6. If NG, replace absolute pressure sensor.










MAP/BARO switch solenoid valve
1. Remove MAP/BARO switch solenoid valve.
2. Check air passage continuity.
3. Check the time required for the solenoid valve to switch. It should be less than 1 second.
4. If NG, replace MAP/BARO switch solenoid valve.