DTC P0108 - MAP SENSOR CIRCUIT HIGH VOLTAGE Pontiac Firebird IV

Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Manifold Absolute Pressure (MAP) sensor measures changes in intake manifold pressure (vacuum). A low voltage signal, 2 volts, is sent to PCM on signal circuit at closed throttle (high vacuum). A high voltage signal, 4 volts, is sent at wide open throttle (low vacuum).

Conditions required to set DTC are

1. Engine running for predetermined time depending on ECT at start-up. Predetermined time ranges from 0.5 second with ECT greater than 86°F (30°C) to 2 minutes with ECT -22°F (-30°C).
2. Engine at idle with engine speed less than 900 RPM.
3. MAP sensor voltage greater than 4.2 volts.
4. No TP sensor DTCs are set.
5. Conditions present for greater than 200 crankshaft revolutions.