GASKET 5M5999 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with a sensor supply. Also, use this procedure if any one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
678-3 ECU 8 Volts DC Supply : Voltage Above Normal The digital sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
678-4 ECU 8 Volts DC Supply : Voltage Below Normal The digital sensor supply voltage is below normal for two seconds.
3509-3 Sensor Supply Voltage 1 : 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.
3509-4 Sensor Supply Voltage 1 : Voltage Below Normal The analog sensor supply voltage is below normal for two seconds.
3510-3 Sensor Supply Voltage 2 : 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.
3510-4 Sensor Supply Voltage 2 : Voltage Below Normal The analog sensor supply voltage is below normal for two seconds. System Operation (Primary ECM)The primary and/or secondary Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Atmospheric pressure sensor (Primary ECM)
Crankcase pressure sensor (Primary ECM)
Turbocharger outlet pressure sensor (Primary & Secondary ECM)
Jacket water coolant pressure sensor (Primary & Secondary ECM)
Filtered engine oil pressure sensor (Primary & Secondary ECM)
Unfiltered engine oil pressure sensor (Primary & Secondary ECM)
Filtered fuel pressure sensor (Primary & Secondary ECM)
Unfiltered fuel pressure sensor (Primary)
Left turbocharger inlet pressure sensor (Primary ECM)
Right turbocharger inlet pressure sensor (Primary ECM)The ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensors:
Left turbocharger turbine inlet temperature sensor (Primary ECM)
Right turbocharger turbine inlet temperature sensor (Primary ECM)System Operation (Secondary ECM)This engine utilizes a redundant control system in the case of an ECM failure. If the primary ECM fails, the secondary ECM provides for engine control and engine system monitoring. The secondary ECM utilizes several additional active sensors to monitor engine operation.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.If applicable, when a -10 code is logged, this code indicates that the 5 V supply is not available at the sensor connector. During normal engine operation, each of the signals from the pressure sensors fluctuate slightly. When the 5 V supply becomes unavailable at the pressure sensor connector, the signal from that sensor floats to a midrange value. The signal will not fluctuate. If the signal from the sensor remains abnormally steady for more than 30 seconds, the ECM will activate this code.Note: The sensors are