REGULATOR-WATER TEMPERATURE 1028392 - Caterpillar

System Operation Description:The digital sensor supply provides power to all of the digital sensors on the engine. The Electronic Control Module (ECM) supplies 8.0 0.4 VDC from the ECM connectors J1/P1 and J2/P2 to each digital sensor connector pin "A". The digital sensor reference is used as the return line for the digital sensors, speed/timing sensors, and the switch inputs to the ECM. The digital reference line is from the ECM connector J1/P1 and J2/P2 to each digital sensor connector pin "B". The digital sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM. The digital sensors are not protected from overvoltage.The following list contains a description of the digital sensors that are found on the engine.Left exhaust temperature sensor - The ECM uses the signal from the sensor to monitor left exhaust temperature. The sensor is mounted in the left exhaust manifold before the turbocharger. The sensor's output frequency is 500 Hz with a pulse width that varies with the exhaust temperature. The output signal is referred to as a duty cycle or as a pulse width modulated signal. The output signal is expressed as a percentage between 0 and 100 percent. The Caterpillar Electronic Technician (ET) will display the exhaust temperature as a value between 49 °C to 850 °C (120 °F to 1562 °F). If the actual temperature is between −40 °C to 49 °C (−40 °F to 120 °F), the display will read 30 °C (86 °F). If the temperature is above 851 °C (1564 °F), the display will read 851 °C (1564 °F).Right exhaust temperature sensor - The ECM uses the signal from the sensor to monitor right exhaust temperature. The sensor is mounted in the right exhaust manifold before the turbocharger. The sensor's output frequency is 500 Hz with a pulse width that varies with the exhaust temperature. The output signal is referred to as a duty cycle or as a pulse width modulated signal. The output signal is expressed as a percentage between 0 and 100 percent. The Cat ET will display the exhaust temperature as a value between 49 °C to 850 °C (120 °F to 1562 °F). If the actual temperature is between −40 °C to 49 °C (−40 °F to 120 °F), the display will read 30 °C (86 °F). If the temperature is above 851 °C (1564 °F), the display will read 851 °C (1564 °F).
Illustration 1 g01017251
Typical example
Test Step 1. Check for Connector Damage
Turn the Engine Control Switch (ECS) to the OFF/RESET position.
Turn the battery disconnect switch to the OFF position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Inspecting Electrical