Manifold Absolute Pressure Sensor

This procedure covers the removal and replacement of the Manifold Absolute Pressure (MAP) sensor on the 5.9L Cummins diesel engine, which monitors intake manifold pressure for fuel delivery and boost control.

Warnings

Tools required

Parts

• Manifold Absolute Pressure (MAP) sensor × 1 — Mopar 56028807 or equivalent

Preparation

1. Allow the engine to cool completely if recently operated
2. Disconnect the negative battery cable to prevent electrical shorts
3. Locate the MAP sensor on the driver's side of the intake manifold near the intake horn
4. Clean the area around the MAP sensor to prevent debris from entering the intake manifold

Procedure

1. 1

   Disconnect MAP sensor electrical connector
   Press the locking tab on the MAP sensor electrical connector and carefully pull the connector straight off the sensor. Do not twist or pull on the wiring itself. Inspect the connector pins for corrosion or damage.
2. 2

   Remove MAP sensor mounting screws
   Verify sensor mounting type: the Cummins boost/MAP sensor may be a threaded-body sensor that screws directly into the intake manifold bung (removed with a wrench/socket), or a flange-mounted sensor with retaining screws. Remove the appropriate fasteners for your specific configuration. Keep the screws in a clean location for reinstallation.
   Torque spec

   MAP Sensor Screws3 Nm (2 lb-ft)
3. 3

   Remove MAP sensor from intake manifold
   Carefully pull the MAP sensor straight out of the intake manifold. There may be a rubber grommet or O-ring seal that comes out with the sensor. Inspect the sensor port in the manifold and remove any debris or old seal material.
4. 4

   Inspect sensor port and seal
   Examine the MAP sensor mounting port in the intake manifold for cracks, damage, or excessive carbon buildup. If a rubber grommet or O-ring is present, inspect it for cracks or deterioration and replace if necessary. Clean the mounting surface with a shop towel.
5. 5

   Install new MAP sensor
   Ensure any O-ring or seal is properly positioned on the new MAP sensor. Align the sensor with the mounting holes and carefully press it straight into the intake manifold port until it seats fully against the mounting surface. Ensure the sensor is oriented correctly with the electrical connector facing outward for easy access.
6. 6

   Install and torque MAP sensor mounting screws
   Install the sensor fastener(s) or thread the sensor body into the manifold bung by hand, then tighten to the manufacturer-specified torque. Do not overtighten as the sensor body can crack. Verify the correct torque spec and fastener configuration for your model year. Do not overtighten as the sensor body can crack.
   Torque spec

   MAP Sensor Screws3 Nm (2 lb-ft)
7. 7

   Reconnect electrical connector
   Clean the electrical connector terminals with electrical contact cleaner if necessary. Align the connector with the MAP sensor and push firmly until you hear or feel a positive click, indicating the locking tab has engaged. Gently tug on the connector to verify it is securely locked.
8. 8

   Reconnect battery and clear codes
   Reconnect the negative battery cable. If a scan tool is available, clear any stored diagnostic trouble codes related to the MAP sensor. The ECM will relearn sensor parameters during normal operation.

Reassembly

1. Ensure all electrical connections are secure and properly locked
2. Verify no tools or parts were left in the engine compartment
3. Double-check that the MAP sensor mounting screws are torqued to specification

Verification

• Start the engine and verify it runs smoothly without rough idle or excessive smoke
• Check for any vacuum leaks around the MAP sensor installation
• If available, use a scan tool to verify the MAP sensor is reading appropriate values (typically 10-15 psi at idle, higher under boost)
• Test drive the vehicle to confirm proper acceleration and boost response
• Verify no check engine light or MAP sensor-related diagnostic trouble codes are present

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle