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The Air Intake Sensor (AIP) is threaded into the intake manifold. See Figure 27369 . The Series 50G natural gas engines use a wide range sensor that allows pressure measurement under conditions of either manifold vacuum or boost. ‪

1. Intake Manifold ‪

5. Bolt ‪

2. Intake Manifold Inlet ‪

6. Air Temperature Sensor (different location on the high pressure fuel system) ‪

3. Intake Manifold Gasket ‪

7. Bolt ‪

4. Cylinder Head ‪

8. Turbo Boost Sensor ‪

Air Intake Pressure Sensor Series 50G

This device is a pressure sensor that sends an electrical signal to the ECM. The ECM uses this information to compute the amount of air entering the engine. Fuel supply is regulated by the TBS information to control engine air fuel ratio. The AIP information is also used to control ignition timing. ‪

Note: S50G GFI controlled fuel system that has been converted to the DDEC controlled closed loop fuel system, the AIP was moved from the intake manifold to the side of the intake elbow.

Repair or Replacement of Air Intake Pressure Sensor

The AIP is non-serviceable and must be replaced as an assembly. No adjustment is required. ‪

Removal of Air Intake Pressure Sensor

Remove the AIP as follows: ‪

  1. Disengage the locking tang on the AIP connector body. Grasp the terminal body and gently pull it from the sensor.
  2. Remove the AIP from the intake manifold.

Installation of Air Intake Pressure Sensor

Install the AIP as follows: ‪

Note: The AIP is an electronic device. Use care during installation.

  1. Install the AIP to the intake manifold.
  2. Engage the locking tang on the AIP connector body. Grasp the terminal body and gently pull it towards the sensor
  3. Put petroleum jelly on O-ring to hold it in position.
  4. Turn the ignition to the "ON" position. Observe or read any diagnostic codes. If any codes other than 25 appears, refer to the DDEC II Troubleshooting Guide , 6SE489, or DDEC III/IV Single ECM Troubleshooting Guide, 6SE497.