TERMINAL KIT 1409944 - Caterpillar

This procedure covers the following diagnostic codes:
Table 1
Diagnostic Trouble Codes for Sensor Supplies
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
678-3 41-3 ECU 8 Volts DC Supply : Voltage Above Normal The ECM detects the following conditions:
The 8 VDC supply is more than 8.8 VDC for more than one second.
The ECM has been powered for more than 3 seconds.
Diagnostic code 168-4 is not active.
The ECM will log the diagnostic code and the warning lamp will illuminate while this diagnostic code is active.
The engine may be limited to low idle.
678-4 41-4 ECU 8 Volts DC Supply : Voltage Below Normal The ECM detects the following conditions:
The 8 VDC supply is less than 7.2 VDC for more than one second.
The ECM has been powered for more than 3 seconds.
Diagnostic code 168-4 is not active.
The ECM will log the diagnostic code and the warning lamp will illuminate while this diagnostic code is active.
The engine may be limited to low idle.
An active diagnostic code may not cause any noticeable effect on engine response unless the voltage drops below 6.5 VDC.
3509-3 262-3 Sensor Supply Voltage 1 : Voltage Above Normal The Electronic Control Module (ECM) detects the following conditions:
The 5 VDC supply for the sensors is greater than 5.16 VDC for more than one second.
The ECM has been powered for at least 3 seconds.
Diagnostic code 168-4 is not active.
The warning lamp will come on. The ECM sets all the sensors on the 5 VDC circuit to the default values.
The engine will be derated.
3510-3 2131-3 Sensor Supply Voltage 2 : Voltage Above Normal
3509-4 262-4 Sensor Supply Voltage 1 : Voltage Below Normal The ECM detects the following conditions:
The 5 VDC supply for the sensors is less than 4.84 VDC for more than one second.
The ECM has been powered for at least 3 seconds.
Diagnostic code 168-4 is not active.
The warning lamp will come on. The ECM sets all the sensors on the 5 VDC circuit to the default values.
The engine will be derated.
3510-4 2131-4 Sensor Supply Voltage 2 : Voltage Below Normal Note: A 678-XX or 41-XX diagnostic code indicates a fault in the 8 VDC circuit on the J1/P1 connector. A 3509-XX or 262-XX diagnostic code indicates a fault in the 5 VDC circuit on the J2/P2 connector. A 3510-XX or 2131-XX diagnostic code indicates a fault in the 5 VDC circuit on the J1/P1 connector.The following background information is related to this procedure:The ECM supplies regulated +5 VDC to the following sensors on P2:1:
Barometric pressure sensor
Intake manifold air pressure sensor
Fuel pressure sensor
Engine oil pressure sensor
NRS intake pressure sensor
NRS differential pressure sensor
NRS valve position sensor
Exhaust Back Pressure Regulator (EBPR) position sensorThe ECM supplies regulated +5 VDC to the analog throttle position sensors (if equipped) and the aftertreatment ID module on P1:72.The ECM supplies regulated +8 VDC to the following sensors on P1:56:
DPF in /SCR in temperature sensor
Digital throttle position sensors (if equipped)
Coolant level sensor (if equipped)
Fuel/water separator level sensor (if equipped)A diagnostic code can be caused by the following conditions:
An open circuit in