Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
The MAP sensor signal voltage is lower than expected, indicating a faulty sensor, wiring issue, or reference voltage problem. This prevents the engine computer from accurately calculating fuel mixture and ignition timing, causing starting and running problems.
What You Might Notice
- Hard to start or difficult starting
- Long cranking times before engine fires
- Sputtering and engine misfires while driving
- Black smoke from exhaust
- Poor fuel economy
- Engine dies or stalls intermittently
- Check engine light illumination
Most Common Causes
- 1
Faulty MAP sensor
The MAP sensor has failed or is producing an incorrect low signal voltage. This is the most common cause of P0107.
- 2
Wiring or connector issues
The signal wire between the MAP sensor and PCM is open, shorted, or has a loose connection causing signal loss.
- 3
5V reference circuit problem
The 5-volt reference supply circuit from the PCM to the MAP sensor is open, shorted, or not providing proper voltage.
- 4
PCM or ground circuit fault
The ground circuit for the MAP sensor is open or the PCM itself has failed and cannot provide the reference voltage.
How to Diagnose It
- 1
Check Faulty MAP sensor — The MAP sensor has failed or is producing an incorrect low signal voltage. This is the most common cause of P0107.
- 2
Check Wiring or connector issues — The signal wire between the MAP sensor and PCM is open, shorted, or has a loose connection causing signal loss.
- 3
Check 5V reference circuit problem — The 5-volt reference supply circuit from the PCM to the MAP sensor is open, shorted, or not providing proper voltage.
- 4
Check PCM or ground circuit fault — The ground circuit for the MAP sensor is open or the PCM itself has failed and cannot provide the reference voltage.
How to Fix It
- 1
Replace MAP sensor
Remove the old MAP sensor from the intake manifold or air intake, disconnect the electrical connector, and install a new OEM or equivalent sensor with proper gasket.
- 2
Inspect and repair wiring
Check the wiring harness from the MAP sensor to the PCM for damage, corrosion, or loose terminals. Repair or replace damaged sections and ensure all connectors are fully seated.
- 3
Check and repair ground circuit
Verify the ground wire from the MAP sensor to the engine block or chassis is clean and tight. Clean corroded terminals and re-secure loose connections.
- 4
Test PCM and reference voltage
Use a multimeter to verify the PCM is supplying 5V reference voltage to the MAP sensor circuit. If voltage is absent, the PCM may require replacement or reprogramming.
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