P0107 on 2018-2019 Ford Explorer 3.5L EcoBoost: MAP Sensor Low Input Causes and Fixes

What's Unique About the 2018-2019 Ford Explorer

The 3.5L EcoBoost engine is a twin-turbocharged, direct-injection engine that relies heavily on precise pressure readings for performance. Ford uses a combined Manifold Absolute Pressure and Temperature (MAPT) sensor. For the 2018-2019 model years, this specific sensor has a high failure rate, prompting Ford to issue Technical Service Bulletin (TSB 19-2212). This TSB points directly to the sensor as the likely cause for P0107, often accompanied by P0108 and P0109, on the Explorer, Flex, Taurus, and Lincoln MKT. The failure is so common that the TSB essentially advises replacing the sensor without extensive diagnostics, making the repair unusually straightforward for this specific platform.

Symptoms You May Notice

• Check Engine Light (MIL) illuminated
• Powertrain Malfunction (Wrench) Lamp illuminated
• "Service AdvanceTrac" me 🎬 Watch: How this sensor fault triggers AdvanceTrac warnings.ssage
• "Hill Start Assist Not Available" message
• Lack of power or sluggish acceleration, may feel like a transmission issue.
• Rough or unstable idle
• Engine stalling, sometimes unexpectedly in traffic or when letting off the throttle.
• Poor fuel economy
• Cruise control may be inoperative.

Most Likely Causes

1. Faulty Manifold Absolute Pressure and Temperature (MAPT) Sensor 🔴 High Probability → Shop Manifold Absolute Pressure Sensor This is a well-documented failure for this specific engine and year range, as confirmed by Ford TSB 19-2212. The sensor can fail internally or become contaminated by oil and carbon from the PCV system, leading to incorrect voltage readings.
   How to confirm: With the key on and engine off, use a scan tool to compare the MAP sensor pressure reading to the Barometric Pressure (BARO) reading. Per the original TSB 19-2183, if the MAP reading differs from the BARO reading by more than 10.35 kPa (1.5 psi), the sensor is faulty and should be replaced. A P0107 code is typically set when the signal voltage drops below 0.5V. 🎬 Watch: How to test and replace a faulty MAP sensor.
   Typical fix: Replace the MAPT sensor. It is located on top of the intake manifold and secured by a single T20 Torx screw. 🎬 Watch: See this specific MAPT sensor replacement walkthrough.
   Est. part cost: $50-$120
2. Wiring Harness or Connector Issue ⚪ Low Probability While much less common than sensor failure on this platform, engine bay heat and vibrations can cause wires to fray or connector pins to corrode over time, leading to a short to ground or an open circuit. However, TSB 19-2212 strongly indicates the sensor itself is the failure point for these specific vehicles.
   How to confirm: Visually inspect the MAPT sensor connector and wiring for any signs of damage, melting, or corrosion. Use a multimeter to check for 5V reference voltage and a good ground at the connector with the key on. If voltage and ground are present, the wiring is likely okay and the sensor is the fault.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the connector pigtail.
   Est. part cost: $15-$50

Rare But Worth Checking

• Powertrain Control Module (PCM) Failure: → Shop Engine Control Module (ECM) This is extremely rare. Before considering PCM replacement, all other possibilities, including the MAPT sensor and its entire circuit, must be exhaustively tested and ruled out. One owner reported a PCM failure due to water intrusion, but this is not a common scenario.
• Major Vacuum Leak: A significant leak from a cracked intake manifold or disconnected vacuum hose could theoretically cause pressure to drop low enough to trigger P0107, but it is not the common cause for this specific vehicle and code. This would likely be accompanied by a loud hissing sound.

Diagnosis Steps

1. Connect an OBD-II scanner and confirm that P0107 is present. Check for other codes like P0108 or P0109, which strongly indicate the MAPT sensor is the fault per TSB 19-2212.
2. Turn the ignition to the 'Key On, Engine Off' (KOEO) position.
3. Access live data on your scan tool. Compare the 'MAP' pressure PID to the 'BARO' (Barometric) pressure PID.
4. If the MAP reading differs from the BARO reading by more than 1.5 psi (10.35 kPa), the MAPT sensor is faulty and must be replaced as per Ford's diagnostic procedure in TSB 19-2183.
5. If the readings are similar, perform a visual inspection of the MAPT sensor connector and its wiring for any obvious damage, corrosion, or loose connections.
6. If no wiring issue is found, the most probable cause is still an intermittently failing MAPT sensor, as documented by Ford. Proceed with replacing the sensor.
7. After replacement, clear the codes with the scan tool and perform a test drive to ensure the issue is resolved and no warning lights return.

Parts You'll Likely Need

• Manifold Absolute Pressure and Temperature (MAPT) Sensor (OEM #AA5Z-9F479-E) — This is the specific part identified by Ford in TSB 19-2212 as the direct cause of P0107 on the 2018-2019 3.5L EcoBoost engine. The Motorcraft service part number may also be listed as CX2619.
  Trusted brands: Motorcraft (OEM), Bosch, Delphi, Standard Motor Products (SMP)
  OEM price range: $80-$120
  Aftermarket price range: $50-$90

Related Codes That Often Appear With This One

• P0108 — This code for 'MAP/BARO Circuit High Input' is also cited in TSB 19-2212. A failing MAPT sensor can send erratic signals that are either too low (P0107) or too high (P0108).
• P0109 — This code for 'MAP/BARO Circuit Intermittent' is the third code listed in TSB 19-2212 and points to the same faulty MAPT sensor providing inconsistent readings.

Technical Service Bulletins (TSBs) & Recalls

• TSB 19-2212 (NHTSA ID: 10163568): Published July 3, 2019. Supersedes a previous version and advises replacing the MAPT sensor for P0107, P0108, or P0109 on 2018-2019 Explorer, Flex, Taurus, and MKT 3.5L EcoBoost models.
• TSB 19-2183 (NHTSA ID: 10163264): Published June 4, 2019. The original bulletin outlining the diagnostic procedure (comparing MAP vs BARO PIDs) and identifying the faulty MAPT sensor.

Platform-Specific Known Issues

• A Ford Technical Service Bulletin (TSB 19-2212, which supersedes 19-2183) was issued on July 3, 2019, for 2018-2019 Explorers, Flex, Taurus, and Lincoln MKTs with the 3.5L EcoBoost engine that exhibit P0107, P0108, and/or P0109. The bulletin identifies a faulty MAPT sensor as the cause and advises direct replacement.
• An owner complaint filed with the NHTSA (ODI #11351923) for a 2018 model describes the vehicle stalling in an intersection after displaying the 'Service AdvanceTrac' message and code P0107, highlighting the safety risk.

Mechanic-Grade Diagnostic Values

• MAP Sensor 5V Reference Wire Voltage — expected: ~5.0 V. Failure: No voltage or significantly low voltage points to a wiring or PCM issue, not a sensor failure.
• MAP Sensor Signal Voltage (Key On, Engine Off) — expected: ~4.5 V (at sea level, should correspond to BARO pressure). Failure: A voltage below 0.5V immediately indicates a circuit low fault.
• MAP Sensor Signal Voltage (Engine Idling) — expected: 1.0 V to 2.0 V. Failure: Voltage below 0.5V triggers the P0107 code.
• MAP Sensor Ground Wire Integrity — expected: < 0.1 V or < 0.5 Ω resistance to chassis ground. Failure: Higher readings indicate a poor ground connection, which can cause incorrect sensor readings.

Scan Tool Commands That Help

• Ford IDS / FORScan: Wiggle Test — While monitoring live MAP sensor voltage PIDs, physically wiggle the sensor connector and its associated wiring harness. If the voltage reading becomes erratic or drops out, it indicates an intermittent open or short in the wiring that isn't apparent from a visual inspection alone.

Wiring & Ground Locations

• G104 / G105 — On the left and right front corners of the engine compartment, on or near the fender aprons.. These are key engine ground points for the 2011-2019 Explorer platform. A corroded or loose connection here can cause floating or incorrect voltage readings on various engine sensors, including the MAPT sensor, potentially triggering P0107 even if the sensor and its direct wiring are faultless.
• MAPT Sensor Connector — On top of the intake manifold, towards the rear/passenger side of the engine on the 3.5L EcoBoost.. This is the primary connection point for the sensor. Inspecting the pins for corrosion, spread terminals, or damage is a critical step if the sensor itself tests good. The connector pigtail is a common repair point for wiring issues.

OEM Part Supersession History

• 2R3Z-9F479-AA → AA5Z-9F479-A — Part revision and update.
• AA5Z-9F479-A → AA5Z-9F479-E — Multiple revisions (B, D) occurred between A and E. The 'E' revision is the latest version specified in TSB 19-2212 to correct the P0107/P0108/P0109 issues on the 2018-2019 models.
  Heads up: While older revisions may physically fit, Ford specifically recommends using AA5Z-9F479-E to resolve this known TSB issue. Using an older stock part may lead to a repeat failure.

Diagnostic Flowchart

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0108 — Manifold Absolute Pressure/Barometric Pressure Circuit High. Explicitly listed in Ford TSB 19-2212 as a companion code caused by the exact same MAPT sensor failure on the 3.5L EcoBoost.
• P0109 — Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent. Also covered under TSB 19-2212 as a direct result of the faulty MAPT sensor.
• P0112 — Intake Air Temperature Sensor 1 Circuit Low. The MAPT sensor measures both pressure and temperature; internal sensor failure or oil/carbon contamination from the PCV system can trigger temperature-related codes alongside P0107.
• P0113 — Intake Air Temperature Sensor 1 Circuit High. Related to the temperature-sensing portion of the MAPT sensor, which shares the same wiring harness and connector that may suffer from heat or vibration damage.

Frequently Asked Questions