LONG BLOCK 20R5144 - Caterpillar

Table 1
Diagnostic Codes Table
J1939 Diagnostic Code and Description Comments
678-3
8 VDC Supply : Voltage Above Normal The code is logged.
678-4
8 VDC Supply : Voltage Below Normal The code is logged.
3509-3
5 Volt Sensor DC Power Supply : Voltage Above Normal The code is logged.
All sensors are set to default values.
3509-4
5 Volt Sensor DC Power Supply : Voltage Below Normal The code is logged.
All sensors are set to default values.
3510-3
5 v Sensor DC Power Supply #2 : Voltage Above Normal The code is logged.
Engine power may be derated.
3510-4
5 v Sensor DC Power Supply #2 : Voltage Below Normal The code is logged.
Engine power may be derated.
3563-21
Intake Manifold Pressure Sensor : Data Drifted Low The code is logged.
The 5 VDC supply to the sensor has been lost.
5578-21
Fuel Pressure Sensor - Before Fuel Filter : Data Drifted Low The code is logged.
The 5 VDC supply to the sensor has been lost.
5580-21
Fuel Pressure Sensor - After Fuel Filter : Data Drifted Low The code is logged.
The 5 VDC supply to the sensor has been lost. System OperationThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the sensors.The supply voltage for the sensors is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal 2 of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.The ECM supplies a regulated voltage of 8.0 0.4 VDC to the digital sensor.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If any of the diagnostic codes are active, a sensor may have been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has been damaged.
Illustration 1 g01240891
Sensor connector
(1) 5 V or 8 V sensor supply
(2) Sensor return
(3) Signal
Table 2
Sensor Supply Sensor Supply ECM Location
Sensor Supply #1 Sensors on A4:E4 engine ECM J2 connector
Sensor Supply #2 Sensors on A4:E4 engine ECM J1 connector
Illustration 2 g06204614
Schematic for 5 Volt Sensors.
Illustration 3 g06204620
Schematic for 8 Volts Sensors
Note: The diagram above is a simplified schematic of the ECM - relay circuit. The schematic is electrically correct. However, not all of the possible sensors or harness connectors are shown. Refer to the latest revision of the Electrical Schematic for the complete schematic for your application.Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Determine the Code
A. Connect Cat® ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Turn