Fuel and air

P0107 — Manifold Absolute Pressure (MAP) Sensor Circuit Low Input

Severity: medium Drive with care, to a shop

What P0107 means

The engine control unit reads the voltage from the manifold absolute pressure (MAP) sensor to calculate engine load, cylinder filling and fuel delivery. P0107 is set when that signal drops below the expected minimum, usually because of a failed sensor, an open circuit or a short to ground in its wiring. On some vehicles the same sensor also serves as the barometric pressure reference.

Symptoms

  • Check Engine light on
  • Rough or unstable idle
  • Weak acceleration and low power
  • Higher fuel consumption
  • Hard starting
  • Stalling

Possible causes

  1. Failed MAP sensor
  2. Damaged or corroded wiring or connector at the sensor
  3. Signal wire shorted to ground
  4. Vacuum hose off or cracked at the MAP port
  5. Vacuum leak in the intake system
  6. Faulty PCM (rare)

How to diagnose

  1. Scan for codes and freeze frame data, clear the code and see if it returns.
  2. Inspect the sensor, connector and harness for corrosion, chafing, oil or water.
  3. Check the sensor's vacuum hose and the intake manifold for cracks and leaks.
  4. With key on and engine off, test the sensor's reference voltage (typically about 5 V) and ground.
  5. Watch MAP readings on a scan tool: they should match barometric pressure with the engine off and drop noticeably at idle.
  6. Test the signal wire for opens and shorts to ground with a multimeter, using the wiring diagram for your vehicle.
  7. Apply vacuum with a hand pump and confirm the signal changes smoothly.
  8. If the sensor and wiring are good, have the PCM tested.

Common fixes

  • Replace the MAP sensor
  • Repair or replace damaged wiring and connectors
  • Replace the vacuum hose and fix any intake leak
  • Reflash or replace the PCM (rare)

Questions and answers

What does P0107 mean?

The PCM sees too low a voltage in the MAP sensor circuit. The cause can be the sensor, its wiring or the vacuum hose.

Can I drive with P0107?

Briefly and carefully, only to get it fixed. The engine may run poorly, lose power or stall, so don't put the repair off.

Will replacing the MAP sensor fix it?

Not always. Check the connector, wiring and vacuum hose first, since they are often the real cause and a new sensor won't change anything.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.