P0108

Description
MAP SENSOR CIRCUIT HIGH VOLTAGE

Manifold Absolute Pressure (MAP) sensor responds to changes
in intake manifold pressure. PCM supplies 5-volt reference and ground
for MAP sensor. MAP sensor provides a signal to the PCM relative to
pressure changes in intake manifold pressure (vacuum). A low voltage
signal, about 2 volts on VIN K or 1.5-2.5 volts on VIN 1, is sent to
PCM on signal circuit at closed throttle (high vacuum) idle. A high
voltage signal, about 4 volts or greater on both engines, is sent at
wide open throttle (low vacuum)
Symptoms

• Hard to start
• Long cranking times
• Sputtering/missing
• Loss of power
• Poor shifting
• Blowing black smoke
• Poor fuel economy
• Dies intermittently
• SES Service Engine Soon light

Causes

• Bad MAP sensor
• Disconnected vacuum line
• Open or short in the signal circuit
• Open or short in the 5 Volt reference circuit
• Ground circuit open or shorted

Solutions

• Test MAP sensor, replace if needed
• Check for vacuum leaks
• Check plug for corrosion or damage
• Test signal circuit wire
• Test 5 Volt reference circuit wire
• Test ground circuit wire
• Ensure harness is not routed too close to high-voltage wires, such as spark plug cables.