CONTROL A 3T4831 - Caterpillar

Which Generate This Code:This diagnostic code is recorded when the engine ECM cannot send information or the ECM does not receive the expected information from the CAT data link.The PRCM uses the CAT data link in order to communicate with the engine ECM. The CAT data link consists of two wires. The wires connect the PRCM to the ECM. If the CAT data link fails, the relays will remain in the state required by the last valid input state, unless the relays are programmed to reset to the OFF position. Refer to Systems Operation, "Setpoint Viewing And Programming".Note: The PRCM will not communicate properly with the engine ECM if the data link cable exceeds 30.5 m (100 ft). See Specifications, "Electrical" for additional information.Note: The PRCM is capable of being programmed in order to treat diagnostic codes for the ECM in one of two ways.
Setpoint P03 is 1. The PRCM will display CID 0590 FMI 09 and the PRCM will display CID 0248 FMI 11. The diagnostic codes are displayed as being active. When the diagnostic codes are inactive, the diagnostic codes will NOT be logged.
Setpoint P03 is 2. The PRCM will display CID 0590 FMI 09 and the PRCM will display CID 0248 FMI 11. The diagnostic codes are displayed as being active. When the diagnostic codes are inactive, the diagnostic codes will be logged.Test Step 1. INSPECT HARNESS CONNECTORS
Inspect the harness connections that are related to the data link.
Make sure that connectors are free of dirt, moisture and debris. Ensure that the connections are tight.
If necessary, repair the harness or replace the harness.
Check the status of the diagnostic code indicator. Expected Result:The diagnostic code indicator is ON. Results:
YES - The diagnostic code indicator is ON. The diagnostic code remains present. Proceed to test step 2.
NO - The diagnostic code indicator is OFF and a harness connection has failed. The diagnostic code is not active. An intermittent connection exists in the data link circuits of the harness. Watch for a recurrence of this diagnostic code. Stop.Test Step 2. CHECK FOR A SHORTED HARNESS
If equipped, turn the disconnect switch to the OFF position. If the system is NOT equipped with a disconnect switch, disconnect the battery negative cable.
Disconnect the wiring harness connector from the engine ECM and disconnect the wiring harness connector from the PRCM.
At the harness connector for the PRCM, measure the resistance from contact 19 to RM1 and RM28. Then, measure the resistance from contact 20 to RM1 and RM28.Expected Result:The resistance is greater than 5000 Ohms for each measurement.Results:
YES - The resistance is greater than 5000 Ohms for each measurement. The resistance is correct. Proceed to test step 3.
NO - Resistance is less than 5000 Ohms for one or more of the measurements. The short is in the circuit with the low resistance measurement.Repair: Repair the wiring harness or replace the wiring harness. Stop.Test Step 3. CHECK THE ENGINE ECM
Disconnect the harness from the engine ECM.
If equipped, turn the disconnect switch and the ECS