PISTON 1M4486 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with the sensor or if any one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
110-3 Engine Coolant Temperature Sensor voltage above normal The engine Electronic Control Module (ECM) detects signal voltage that is more than 4.95 VDC for 8 seconds.
The ECM has been powered for at least 2 seconds. The code is logged if the engine has been running for more than 7 minutes. The ECM uses the last valid engine coolant temperature. If the diagnostic code is active at start-up the ECM will use intake manifold temperature. If intake manifold air temperature is not valid, the ECM will default to 90 °C (194 °F) for engine coolant temperature. The ECM will activate the cooling fan after this code has been active for more than 8 seconds.
110-4 Engine Coolant Temperature Sensor voltage below normal The ECM detects signal voltage that is less than 0.2 VDC for 8 seconds.
The ECM has been powered for at least 2 seconds.
172-3 Intake Manifold Air Temperature Sensor voltage above normal The engine ECM detects signal voltage that is more than 4.95 VDC for 8 seconds.
The ECM has been powered for at least 2 seconds. The ECM will log the diagnostic code. The ECM will flag the intake manifold air temperature as invalid data and the intake manifold air temperature is set to a default value of 70 °C (158 °F).
172-4 Intake Manifold Air Temperature Sensor voltage below normal The ECM detects signal voltage that is less than 0.2 VDC for 8 seconds.
The ECM has been powered for at least 2 seconds.
174-3 Fuel Temperature Sensor voltage above normal The engine Electronic Control Module (ECM) detects signal voltage that is more than 4.95 VDC for 8 seconds.
The ECM has been powered for at least 2 seconds. The code is logged. The ECM will flag the fuel temperature as invalid data and the fuel temperature is set to a default value of 40 °C (104 °F).
174-4 Fuel Temperature Sensor voltage below normal The ECM detects signal voltage that is less than 0.2 VDC for 2 seconds.
The ECM has been powered for at least 2 seconds. System OperationUse this procedure to troubleshoot any suspect problems with the following sensors:
Coolant temperature sensor
Intake manifold air temperature sensor
Fuel temperature sensorThe sensor signal for the passive sensor is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the passive sensors is routed from the ECM to terminal 2 of each sensor connector.
Illustration 1 g01365935
Schematic for the passive analog sensors
Illustration 2 g06112437
Locations of the components for the passive analog sensors (typical left side engine view)
(1) Fuel temperature sensor
(2) Intake manifold air temperature sensor
(3) J2/P2 ECM connectors
Illustration 3 g06122633
Locations of the components for the passive analog sensors (typical top engine view)
(4) Engine coolant temperature sensor
Illustration 4 g06122641
Locations of the components for the passive analog sensors (typical front engine view)
(5) Engine oil temperature