P0107: MAP/Barometric Pressure Circuit Low (Meaning, Causes, Fixes)
What P0107 means
The MAP sensor measures the pressure (vacuum) inside the intake manifold. Per RepairPal, the engine computer (PCM) uses it to control the air-fuel ratio, ignition timing and many emission controls; OBD-Codes.com adds that the signal is essential for deciding how much fuel to deliver. OBD-Codes.com explains that the PCM supplies the sensor with 5 volts and the sensor returns a signal of about 1 to 4.5 volts depending on engine load. The two sources describe the trigger differently. OBD-Codes.com says P0107 sets when the PCM sees the MAP signal below 0.25 volt. RepairPal says it sets when the signal stays under 0.5 volt for 10 seconds or more while the throttle position, RPM and oxygen sensor values are changing. Check the specs for your vehicle. Related MAP codes are P0105 (circuit), P0106 (range/performance), P0108 (circuit high) and P0109 (intermittent).
Severity: can I keep driving?
Drive with caution, fix soon
Get it checked soon. RepairPal rates P0107 'Urgent', and OBD-Codes.com says a low MAP signal will likely make the engine very hard to start and can make it sputter, blow black smoke or die intermittently. If the engine stalls, won't start or runs very rough, don't drive it (especially in traffic) until it's fixed.
Common symptoms
- Check engine light on (both sources)
- Hard starting (both sources); OBD-Codes.com says a very difficult time starting is likely, with long cranking times
- Lower fuel economy (both sources)
- Sputtering or missing, and noticeably poor performance (OBD-Codes.com lists sputtering; RepairPal says poor performance in some cases)
- Black smoke from the exhaust (listed by OBD-Codes.com)
- Engine dies intermittently (listed by OBD-Codes.com)
Likely causes
Roughly most to least common, based on the sources below. Your vehicle may differ.
- Faulty MAP/barometric pressure sensor (both sources)
- Faulty or corroded MAP sensor wiring or connections (RepairPal); OBD-Codes.com specifically lists an open or short in the signal circuit, the 5-volt reference circuit or the ground circuit
- On Chrysler products, another sensor that shares the PCM's 5-volt reference (such as a shorted crank sensor or vehicle speed sensor) pulling the reference down (per OBD-Codes.com)
- Faulty PCM (listed by OBD-Codes.com); not listed by RepairPal
Diagnostic steps you can do
Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.
- Read all stored codes and note the freeze frame data. Several 'low voltage' sensor codes at once can point to a shared 5-volt reference problem rather than several bad sensors.
- Check the MAP sensor connector and harness for corrosion, loose terminals, chafing or burned wiring.
- With the engine running, watch the MAP voltage on a scan tool. OBD-Codes.com says if it reads under 0.5 volt, turn the engine off, unplug the sensor and check for 5 volts on the reference wire with a multimeter.
- If the 5-volt reference is there, OBD-Codes.com's next test is jumpering the reference wire to the signal wire; the scan tool should then read 4.5 to 5 volts. If it does, the sensor is the likely fault; if not, the signal wire has an open or short.
- If everything checks out, do a wiggle test with the engine running: move the harness and connector and tap the sensor while watching the voltage.
- Clear the code and see if it returns before buying parts.
Typical fixes
- Repair a short to ground or an open in the MAP sensor signal, 5-volt reference or ground wiring
- Clean or repair corroded MAP sensor connections
- Find and unplug the shorted sensor pulling down a shared 5-volt reference (Chrysler tip from OBD-Codes.com)
- Replace the MAP sensor once wiring checks out, or if its reading doesn't change when you apply vacuum to it (OBD-Codes.com says about 4.5 volts with no vacuum, dropping as vacuum is added)
- Check PCM powers and grounds, and repair or replace the PCM, only if the 5-volt reference is missing at the PCM connector itself (OBD-Codes.com)
Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.
🛠 When to call a pro
- The engine stalls, won't start or runs very rough
- The 5-volt reference is missing and you'd need to back-probe the PCM connector to trace it
- RepairPal warns the MAP sensor is often replaced when the real cause is a short to ground in its wiring or an open in the 5-volt reference circuit
- The code keeps coming back after a new sensor
Where to buy
Plain search links. Always match parts to your exact year, make, model and engine.
FAQs
Does P0107 mean I need a new MAP sensor?
Not necessarily. Both sources list wiring problems as a cause, and RepairPal says the MAP sensor is often replaced when the real problem is a short to ground in its wiring or an open 5-volt reference circuit. Test the wiring first.
What's the difference between P0107 and P0108?
Both are MAP sensor circuit codes. P0107 means the signal voltage is too low; P0108 means it's too high.
Is it safe to drive with P0107?
RepairPal rates it 'Urgent', and OBD-Codes.com says the engine may be very hard to start and may die intermittently. Get it diagnosed soon, and don't drive if the engine is stalling or running very rough.
How much does it cost to fix P0107?
Neither source gives a repair cost. It depends on whether it's wiring, the sensor or (rarely) the PCM, so get a diagnosis and a written estimate first.
Sources
Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.