System Inspection

SYSTEM INSPECTION
1. Turn off the A/C switch.
2. Warm up the engine to normal operating temperature and let it idle.
3. Disconnect the vacuum hose from the resonator side of the bypass air solenoid valve No.1 and No.2.

Fig.1 Checking For Vacuum:

4. Place a finger at the bypass air solenoid valve No.1 and No.2 as shown in Fig.1 and verify that there is no vacuum.

Fig.2 Vacuum Pump Connection:

5. Connect a vacuum pump to the manifold absolute pressure sensor and apply 26.7 kPa (200 mmHg, 7.9 inHg) vacuum.
6. Place a finger at the bypass air solenoid valve No.1 and No.2 as shown in Fig.1 and verify that vacuum is felt.
7. If not as specified, inspect following.
- Manifold absolute pressure sensor
- Bypass air solenoid valve
- Vacuum hose for damage or looseness
8. Disconnect the vacuum pump from the manifold absolute pressure sensor, and reconnect the vacuum hose.
9. Position the vehicle on a chassis roller. Shift the selector lever to D and turn the A/C switch to ON.
10. Place a finger at the bypass air solenoid valve No.1 as shown in Fig.1 and verify that vacuum is felt.
11. If there is no vacuum, inspect following.
- ECM terminal 1D (A/C amplifier)
- ECM terminal 1B, 1F (Inhibitor signal)
- Bypass air solenoid valve