Cummins ISB4.5 CM2150 Fault Code: 436 PID: 111 SPN: 105 FMI: 2 Intake Manifold 1 Temperature – Data Erratic, Intermittent, or Incorrect.

Circuit Description
The intake manifold 1 temperature sensor is a variable resistor sensor and is used to measure the temperature of the air entering the intake manifold of the engine. The engine intake manifold temperature value is used by the electronic control module (ECM) for the engine protection system and engine emission control. The ECM supplies 5 volts to the intake manifold temperature signal circuit, and monitors the change in voltage caused by changes in the resistance of the sensor to determine the intake manifold temperature. When the intake air is cold, the sensor (or thermistor) resistance is high. The ECM signal voltage only pulls down a small amount through the sensor to a ground. Therefore, the ECM senses a high signal voltage, or a low temperature. When the intake air is warm, the sensor resistance is low. The signal voltage pulls down a large amount. Therefore, the ECM senses a low signal voltage, or a high temperature.

Component Location
The engine intake manifold temperature sensor is located in the air intake manifold.

Conditions for Running the Diagnostics
This diagnostic consists of two parts. The first part runs when the keyswitch is turned ON and before engine speed is detected. The ECM must not see a key cycle for a period of 8 hours before this part of the diagnostic will run. The second part runs when the engine is running.

Conditions for Setting the Fault Codes
The ECM detects that the engine intake manifold temperature sensor reading is higher or lower than the other temperature sensors on the engine after an extended period of engine OFF time.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
-The ECM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
-The ECM will estimate engine intake manifold temperature.

Conditions for Clearing the Fault Code
-To validate the repair, the engine must be shut down with the keyswitch in the OFF position for a period of 8 hours. After the 8 hour cold soak, turn the key to the ON position but do not start the engine.
-The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
-Use INSITE™ electronic service tool to verify the fault code is inactive.
-This fault code can also be cleared with INSITE™ electronic service tool.

Possible Causes
-In-range malfunction of the engine intake manifold temperature sensor.
-High resistance in the engine intake manifold temperature sensor signal or return lines.