Cummins ISB4.5 CM2150 Fault Code: 2973 PID: 106 SPN: 102 FMI: 2 Intake Manifold 1 Pressure – Data Erratic, Intermittent, or Incorrect.

Circuit Description
The engine control module (ECM) provides a 5 volt supply to the intake manifold pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The intake manifold pressure sensor provides a signal to the ECM on the intake manifold pressure sensor signal circuit. This sensor signal voltage changes, based on the pressure in the intake manifold.

Component Location
The intake manifold pressure/temperature 1 sensor is located in the air intake manifold.

The barometric pressure sensor can be externally mounted on the engine or can be an internal component within the ECM. Check engine wiring diagram for circuit details.

Conditions for Running the Diagnostics
This ECM diagnostic runs in two parts consisting of three separate conditions without keying off between steps:

1. Key ON – Part 1 of this diagnostic runs a sensor rationality check when the keyswitch is initially turned on. If the fault code became active at key ON only, it has failed the first check.

2. Operation – Part 2 of this diagnostic will run a pressure rationality check when the engine is running under normal conditions. The diagnostic runs a check at the following conditions:

>1500 rpm at 100 percent load, for 25 non-consecutive seconds.
1500 rpm and under load, only the >1500 rpm condition needs to be completed.
-If the fault code became active at