P0107 — Manifold Absolute Pressure/Barometric Pressure Circuit Low — 5.9 Cummins 24-Valve (VP44)

Diagnostic reference for 5.9L Cummins 24-Valve (VP44) 1998.5–2002.

Updated October 15, 2026

What it means

The ECM sees the MAP/BARO sensor signal below the valid range. On this platform the MAP sensor provides intake manifold pressure information used for fueling and boost control. A low circuit reading means the ECM is seeing an abnormally low voltage from the MAP/BARO circuit.¹

Most likely causes

1. MAP sensor internal failure or damaged sensor element — Sensor output stuck low or shorted internally, giving a low voltage to the ECM.¹
2. Wiring/connector fault to MAP sensor — chafed, corroded, or loose connection causing low voltage or short to ground — Open or high-resistance in signal wire, or connector contamination, pulls the signal low.¹
3. Reference voltage or ground supply issue to MAP sensor — Loss of 5 V reference or poor sensor ground biases the signal low; inspect power/ground circuits feeding the sensor.¹
4. Boost/intake leak or unmetered air affecting MAP reading at idle/low load — Large post-turbo leak can cause unusually low manifold pressure readings under conditions where ECM expects higher pressure.¹
5. ECM input fault — Internal ECM processing fault can misinterpret a good sensor signal as low.¹

How to diagnose

1. Verify code and freeze frame; confirm P0107 is present and note engine conditions at set.
2. Visually inspect MAP sensor and intake plumbing for damage, oil contamination, and loose connections.
3. Check MAP sensor connector for corrosion, bent pins, and secure latch.
4. Inspect wiring harness from MAP sensor to ECM for chafing, heat damage, and proper routing.
5. Using a scan tool, view live MAP/BARO voltage and compare to key-on/engine-off barometric reading and idle values.
6. Check MAP sensor reference voltage and ground at the sensor connector with key on.
7. If electrical tests are normal, inspect intake/boost plumbing for leaks, cracked hoses, loose clamps, and damaged intercooler boots.
8. Clear codes and test drive to confirm code return and monitor MAP readings under load.
9. If sensor and wiring test good but code persists, evaluate ECM input integrity.
10. Document findings before replacing parts.

Common mistake to avoid

Replacing the turbo before smoke-testing the intake. Boost leaks at intercooler boots, end tanks and clamps are a common cause of low power and underboost codes, and they mimic a failing turbo. Source: BD Diesel — 6.7L Power Stroke problems and real fixes.

Parts and tools you may need

• Digital multimeter
• Scan tool with live data
• Basic hand tools for inspection
• Dielectric grease
• Replacement MAP sensor (if testing indicates failure)

Tools you’ll need

• OBD-II scan tool — Reads live MAP/BARO voltage and freeze frame to confirm P0107 conditions and monitor readings under load.
• Digital multimeter — Checks MAP sensor reference voltage, ground, and signal voltage at the connector to identify low circuit faults.
• Fuel pressure gauge — Verifies fuel system integrity on VP44 engines where low fuel pressure can indirectly affect manifold pressure readings.
• Inspection mirror — Allows visual inspection of MAP sensor and intake/boost plumbing in tight engine bay areas for damage or leaks.

Rough cost and difficulty

Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If wiring faults are found in the engine harness, or if ECM input testing is inconclusive, have a qualified diesel technician perform pinpoint electrical tests. Do not attempt repairs on high-pressure fuel or safety-critical systems without proper training.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources