CAP-BEARING 7T3560 - Caterpillar

System Operation Description:Use this procedure under the following conditions:This procedure covers open circuit diagnostic codes and short circuit diagnostic codes that are associated with the following sensors:
Coolant temperature sensor
Intake manifold air temperature sensorUse this procedure to troubleshoot the system when one of the following diagnostic codes is an active diagnostic code or a recently logged diagnostic code or when a diagnostic code can easily be activated.
0110-03 Engine Coolant Temperature Sensor voltage above normal
0110-04 Engine Coolant Temperature Sensor voltage below normal
0172-03 Intake Manifold Air Temperature Sensor voltage above normal
0172-04 Intake Manifold Air Temperature Sensor voltage below normalThe following background information is related to this procedure:The troubleshooting procedures for the diagnostic codes of each temperature sensor are identical. The temperature sensors are sensors that have two terminals. Pin P2:37 is the common connection for the engine temperature sensors. The sensor common connection is shared between the temperature sensors. The common line is connected to each sensor connector terminal 2. Terminal 1 is the sensor output. The signal voltage from terminal 1 of each sensor is supplied to the appropriate terminal in the P2/J2 connector.Pull-up VoltageThe ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage in order to detect an open in the signal circuit. When the ECM detects the presence of a voltage that is above a threshold on the signal circuit, the ECM will generate an open circuit diagnostic code (3) for the sensor.If the sensor is disconnected at the sensor connector, the presence of pull-up voltage at the sensor connector indicates that the wires from the sensor connector to the ECM are not open or shorted to ground. If the sensor is disconnected at the sensor connector, the absence of pull-up voltage at the sensor connector indicates an open in the signal wire or a short to ground. If the sensor is disconnected at the sensor connector and the voltage at the sensor connector is different from pull-up voltage, the signal wire is shorted to another wire in the harness.The troubleshooting procedures for the diagnostic codes of each temperature sensor are identical. The temperature sensors are passive sensors. The temperature sensor has two terminals. The common line is connected to each sensor connector terminal 2. The signal voltage from terminal 1 of each sensor is supplied to the appropriate terminal at the P2/J2 ECM connector.
Illustration 1 g01459083
Schematic for engine temperature sensors
Illustration 2 g01459099
Pin locations for the temperature sensors on the P2 connector
(37) Ground (GND) Intake Manifold Air Temperature Sensor
(37) Ground (GND) Coolant Temperature Sensor
(42) Signal (SIG) Intake Manifold Air Temperature Sensor
(43) Signal (SIG) Coolant Temperature Sensor
Illustration 3 g01170313
Engine coolant temperature sensor and intake manifold air temperature sensor
(1) Signal (SIG)
(2) Ground (GND) Test Step 1. Verify All Active Diagnostic Codes
Connect the electronic service tool to the data link connector.
Turn the keyswitch to the ON position. Note: Wait at least 30 seconds for activation of the diagnostic codes.
Use the electronic service tool in order to verify if any of the following diagnostic