Code P1800

DTC P1800: VIAS CONTROL SOLENOID VALVE

Description:

The Variable Induction Air Control System (VIAS) control solenoid valve cuts the intake manifold vacuum signal for power valve control. It responds to on/off signals from the ECM. When the solenoid valve is off, the vacuum signal from the intake manifold is cut. When the ECM sends an on signal, the coil pulls the plunger downward and feeds the vacuum signal to the power valve actuator.

Possible Causes:

Malfunction is detected when an improper voltage signal is sent to ECM through VIAS control solenoid valve. Possible causes are:

l VIAS control solenoid valve circuit open or shorted.

L Defective VIAS control solenoid valve.

Diagnostic Procedure:

1. Turn ignition off. Disconnect VIAS control solenoid valve harness connector. See Fig. 74. Turn ignition on. Measure voltage between ground and VIAS control solenoid valve harness connector terminal No. 1 (Red/Yellow wire). If battery voltage exists, go to step 3. If battery voltage does not exist, go to next step.

2. Check the following:
l Check fuse No. 20 (15-amp) located in fuse block under left side of instrument panel.
L Check for poor connection at fuse block connector M19 terminal 11L (Red/Yellow wire). See Fig. 9.
L Check for poor connection at White, 18-pin harness connector F68 (on Maxima) terminal No. 14 (Red/Yellow wire). See Fig. 19. Connector is located under instrument panel.
LCheck for open or short between VIAS control solenoid valve and fuse.

Repair as necessary:

3. Turn ignition off. Disconnect ECM harness connector. See Fig. 5. Check continuity of Yellow/Green wire between VIAS control solenoid valve harness connector terminal No. 2 and ECM harness connector terminal No. 27. See Fig. 17. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.

4. If using CONSULT-II, go to next step. If not using CONSULT-II, go to step 6.

5. Reconnect all harness connectors. Turn ignition on. Perform VIAS SOL VALVE in ACTIVE TEST mode with CONSULT-II. When VIAS SOL VALVE is ON, air should flow between ports "A" and "B", and air should not flow between ports "A" and "C". See Fig. 75. When VIAS SOL VALVE is OFF, air should not flow between ports "A" and "B", and air should flow between ports "A" and "C". It should take less than one second for valve to switch. If operating is as specified, go to step 7. If operation is not as specified, replace VIAS control solenoid valve.

6. Using jumper wires, apply battery voltage between VIAS control solenoid valve terminals. See Fig. 75. Air should flow between ports "A" and "B", and air should not flow between ports "A" and "C". Remove jumper wires. Air should not flow between ports "A" and "B", and air should flow between ports "A" and "C". It should take less than one second for valve to switch. If operating is as specified, go to next step. If operation is not as specified, replace VIAS control solenoid valve.

7. No problem is indicated at this time. Problem may be intermittent.