Intake Manifold Tuning Valve Diagnosis

Intake Manifold Tuning Valve Diagnostic Chart:

Intake Manifold Tuning Valve Circuit:

CIRCUIT DESCRIPTION:
The intake manifold tuning valve is activated through a relay by the PCM during periods of acceleration where engine RPM is over 3000 and throttle position is over 34%.
The intake manifold tuning valve relay is powered by ignition voltage and turned "ON," and "OFF" when the PCM grounds the intake manifold tuning valve control circuit. When the relay is activated, it applies ignition voltage to the intake manifold tuning valve.

TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step determines if the system is functioning at the present time.
2. By cycling the intake manifold tuning valve "ON" and "OFF" will determine if the intake manifold tuning valve relay is operating.
3. This will determine if the intake manifold tuning valve relay has ignition voltage at intake manifold tuning valve relay connector, terminal "30".
4. This will determine if the intake manifold tuning valve relay has ignition voltage at intake manifold tuning valve relay connector, terminal "86".
5. This step will determine if the relay related wiring to valve or the intake manifold tuning valve is at fault.
6. This step will determine if the PCM, intake manifold tuning valve relay or related wiring is at fault.

DIAGNOSTIC AIDS:
TP SENSOR - An intermittent TP sensor output will cause the PCM to receive false input.