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P0108Manifold Absolute Pressure/Barometric Pressure Circuit High

What it means

The MAP sensor signal voltage is higher than the sensor can normally produce (close to 5 V). Most often the signal wire or the sensor ground is open, or the signal is shorted to a supply voltage.

Symptoms

  • Rough idle or hesitation
  • Poor fuel economy or black smoke
  • Limp mode on turbo engines

Common causes

  • Open signal wire (the ECU's pull-up then reads high)
  • Open or high-resistance sensor ground
  • Signal shorted to the 5 V reference or to battery voltage
  • Failed MAP sensor

What to check first

  1. Measure the voltage drop on the sensor ground with the key on (should be under 0.1 V)
  2. Unplug the sensor: the live data should jump to the opposite extreme
  3. Inspect the harness for chafing against other wires or hot parts
Can I drive with P0108? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

How to test the parts behind P0108

MAP and boost pressure sensorWiring, typical values, multimeter and scope tests

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P0108: questions and answers

What does P0108 mean?

P0108: Manifold Absolute Pressure/Barometric Pressure Circuit High. The MAP sensor signal voltage is higher than the sensor can normally produce (close to 5 V). Most often the signal wire or the sensor ground is open, or the signal is shorted to a supply voltage.

What are the symptoms of P0108?

Rough idle or hesitation. Poor fuel economy or black smoke. Limp mode on turbo engines.

What causes P0108?

Open signal wire (the ECU's pull-up then reads high). Open or high-resistance sensor ground. Signal shorted to the 5 V reference or to battery voltage. Failed MAP sensor.

How do you diagnose P0108?

1. Measure the voltage drop on the sensor ground with the key on (should be under 0.1 V) 2. Unplug the sensor: the live data should jump to the opposite extreme 3. Inspect the harness for chafing against other wires or hot parts

Can I drive with P0108?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.