HUB-STER CL- 2164471 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with a sensor supply. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.
Table 1
J1939 Code and Description Comments
678-3
ECU 8 Volts DC Supply : Voltage Above Normal The digital sensor supply voltage is above normal for 2 seconds.
The code is logged.
678-4
ECU 8 Volts DC Supply : Voltage Below Normal The digital sensor supply voltage is below normal for 2 seconds.
The code is logged.
3509-3
Sensor Supply Voltage 1 : Voltage Above Normal The analog sensor supply voltage is above normal for 2 seconds.
The code is logged.
3509-4
Sensor Supply Voltage 1 : Voltage Below Normal The analog sensor supply voltage is below normal for 2 seconds.
The code is logged.
3510-3
Sensor Supply Voltage 2 : Voltage Above Normal The analog sensor supply voltage is above normal for 2 seconds.
The code is logged.
3510-4
Sensor Supply Voltage 2 : Voltage Below Normal The analog sensor supply voltage is below normal for 2 seconds.
The code is logged.
3511–6
Sensor Supply Voltage 3 : Current Above Normal When the output driver for the oxygen sensors is on, the ECM detects a high current in the circuit for 2 seconds.
The code is logged.
The activation of this code is latched by the ECM. The power to the ECM must be powered to reset the power supply. The ECM supplies 24 VDC to the voltage converter for the oxygen sensors through terminal location J1-10 at the ECM. The 3511-6 becomes activated if a short to ground is detected in the harness between the ECM and the voltage converter.The ECM supplies a regulated voltage of 8.0 0.4 VDC to the digital sensors.The ECM supplies a regulated voltage of 5.0 0.2 VDC to the analog 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.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. Repair the sensor supply and check for any active sensor diagnostic codes to determine if a sensor has failed.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Determine if a code is active or logged.
Codes
Result: A -3 or -4 code is active. Note which ECM is reporting the active code.
Proceed to Test Step 2.
Result: A -6 code is active.
Proceed to Test Step 4.
2. Check for a Failed Sensor
A. Connect Cat ET.
B. Disconnect a sensor on the affected sensor supply circuit.
C. Use Cat ET to monitor following:
- Active code changes to logged
D. Connect the affected sensor to the wiring harness.
E. Repeat Step B through Step D for each sensor on the affected sensor supply.
Sensor
Result: The affected sensor supply active code changed