NUT-FULL 1B5358 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with a sensor supply or if any one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
262-3 5 Volt Sensor DC Power Supply voltage above normal The analog sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
262-4 5 Volt Sensor DC Power Supply voltage below normal The analog sensor supply voltage is below normal for two seconds.
263-3 Digital Sensor Power Supply (8V Or 12V) voltage above normal The digital sensor supply voltage is above normal for two seconds.
263-4 Digital Sensor Power Supply (8V Or 12V) voltage below normal The digital sensor supply voltage is below normal for two seconds. System OperationThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Aftercooler temperature sensor
Atmospheric pressure sensor
Coolant temperature sensor
Crankcase pressure sensor
Filtered engine oil pressure sensor
Filtered fuel pressure sensor
Turbocharger outlet pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Unfiltered engine oil pressure sensor
Unfiltered fuel pressure sensorThe ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensors:
Left exhaust temperature sensor
Right exhaust temperature sensorThe supply voltage for the sensors is routed from the ECM to terminal A of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal B 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.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If the diagnostic code 262-3 or the diagnostic code 263-3 is logged, it is possible that all of the sensors have been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has failed.
Illustration 1 g01327574
Typical schematic 5 V supply
Illustration 2 g01327527
Typical schematic 8 V supply
Illustration 3 g01327649
P1 ECM connector
(P1-2) "5 V analog sensor supply (LH)"
(P1-3) "Analog sensor return (LH)"
(P1-4) "8 V digital sensor supply (LH)"
(P1-5) "Digital sensor return (LH)"
(P1-18) "5 V analog sensor supply (RH)"
(P1-35) "Analog sensor return (RH)"
Illustration 4 g01327661
P2 ECM connector
(P2-56) "8 V digital sensor supply (RH)"
(P2-66) "Digital sensor return (RH)"
Illustration 5 g01327616
Terminal locations for the A-C1/E-C2 RH rigid harness connectors and the C-C1/E-C1 LH rigid harness connectors
(Terminal A) "Analog sensor return (RH)"
(Terminal B) "5 V analog sensor supply (RH)"
(Terminal C) "8 V digital sensor supply (RH)"
(Terminal D) "Digital sensor return (RH)"
Illustration 6 g01320528
Connector locations
(1) A-C1/E-C2 RH rigid harness connectors
(2) A-C2/J-C2 RH rigid harness connectors
(3) P-C1/A-C90 Connectors for the power distribution panel
(4) P-C2/A-C91 Connectors for the power distribution panel
(5) G-C6/F-C2/F-C1/A-C92 Connectors for a RH Control panel
(6) C-C22 Primary ECM connector P2
(7) C-C15 Primary ECM connector P1
(8) C-C28 Secondary ECM connector P2
(9) C-C29 Secondary ECM connector P1
(10) G-C6/F-C2/F-C1/C-C17 Connectors for a LH Control panel
(11) C-C18/TB-C1 Customer connectors
(12) C-C2/J-C1 LH rigid harness connectors
(13) C-C1/E-C1 LH