CARRIER A-DIFF 3K2509 - Caterpillar

Use this procedure to troubleshoot a fault with the soot sensor. Also, use this procedure if the diagnostic code in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table for Soot Sensor
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
4783-3 3397-3 DPF #1 Mean Soot Signal : Voltage Above Normal The Electronic Control Module (ECM) detects the following conditions:
The signal voltage for the soot sensor is greater than 32 VDC for 60 seconds.
The warning lamp will come on. The ECM will log the diagnostic code.
The EBPR may close as a precaution.
4783-4 3397-4 DPF #1 Mean Soot Signal : Voltage Below Normal The Electronic Control Module (ECM) detects the following conditions:
The signal voltage for the soot sensor is less than 9 VDC for 60 seconds.
The warning lamp will come on. The ECM will log the diagnostic code.
The EBPR may close as a precaution.
4783-9 3397-9 DPF #1 Mean Soot Signal : Abnormal Update Rate The ECM detects the following conditions:
There is no signal from the soot sensor.
The warning lamp will come on and the ECM will log the diagnostic code.
The ECM will use the last good value for the signal.
4783-12 3397-12 DPF #1 Mean Soot Signal : Failure The ECM detects the following conditions:
The soot sensor has failed.
The warning lamp will come on and the ECM will log the diagnostic code.
4783-13 3397-13 DPF #1 Mean Soot Signal : Calibration Required The ECM detects the following conditions:
The soot sensor has not been calibrated by the manufacturer.
The warning lamp will come on and the ECM will log the diagnostic code.
4783-21 3397-21 DPF #1 Mean Soot Signal : Data Drifted Low The ECM detects the following conditions:
The soot sensor has not received a valid signal from the soot antenna for at least 60 seconds.
The warning lamp will come on and the ECM will log the diagnostic code.
Table 2
Required Tools
Tool Part Number Part Description Qty
A 366-7782 Attenuator 1 The following conditions must exist before any of the preceding codes will become active:
The ECM has been powered for at least 60 seconds.
There are no active 168 codes.The following background information is related to this procedure:The soot sensor is powered from the switched battery voltage. A signal is sent by the soot sensor to one soot antenna. The signal that is received by the other antenna is sent back to the soot sensor. The signal is attenuated by the soot in the Diesel Particulate Filter (DPF). The soot sensor calculates the soot load in the DPF by measuring the attenuation of the signal.
Illustration 1 g06156441
Schematic diagram for the soot sensor circuit
Illustration 2 g02458558
View of the pin locations on the P1 connector for the soot sensor
(29) CAN B +
(21) CAN B -Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Inspect the connectors for the speed/timing sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of