CHAIN 3D4343 - Caterpillar

System Operation Description:Analog inputs are connected to resistive type sensors, current type sensors, PWM type sensors, or analog voltage sensors. Analog inputs are connected to on the engine, generator, or supporting systems. The OCP converts the resistive sensor values into levels, temperatures, and pressures depending on how the input is configured. Six programmable thresholds are provided. These thresholds include both high and low for each of the three supported data types. The appropriate thresholds are selected based on the analog input type configuration set points. The OCP will also detect sensor diagnostics for shorted high and shorted low conditions.An active analog input can be programmed to cause an alarm or a shutdown. For programming of the spare inputs, see System Operation, "Analog Input Programming".Conditions Which Generate This Code: This code is generated when the measured spare analog input value goes above or below the programmed threshold for a duration that can be configured.Test Step 1. PERFORM THE INITIAL CHECK
Use the Caterpillar Electronic Technician (Cat ET) in order to check for active diagnostic codes on the engine ECM. If any codes are present, then correct the diagnostic codes first. Expected Result:No other diagnostic codes or indicators are active on the engine ECM.Results:
OK - No other diagnostic codes or indicators are active. Proceed to Test Step 2.
NOT OK - Another engine ECM diagnostic code is active.Repair: Exit this procedure. Troubleshoot the active code or indicator. Refer to the engine Troubleshooting manual for your particular generator set.STOPTest Step 2. CHECK THE SET POINTS
View the analog input set points. Make a note of the set points. See Testing and Adjusting, "Electronic Control Module (ECM) - Configure". Compare the set points against the default set points of the particular generator set. Expected Result:The set points are correct.Results:
OK - The set points are correct for your particular generator set. Proceed to test step 3
NOT OK - The set points are NOT correct.Repair: Reprogram the set points. Reset the engine. Resume normal operation and verify that the problem has been corrected. STOPTest Step 3. CHECK THE ANALOG INPUT DEVICE WIRING
Check the wiring to the corresponding spare analog input for an unwanted short circuit. The short can be to the battery negative ("B-"). The short can be to the battery positive terminal ("B+"). Carefully check ALL wires that are connected to the appropriate analog input for abrasion or worn spots in the insulation that could be causing the short. Check the wires in the generator control panel. Check the wires in the engine harness. Refer to the appropriate wiring diagrams for the circuit that is being checked. Expected Result:The wiring is correct.Results:
OK - No problems can be found with the analog input wiring. Proceed to test step 4.
NOT OK - The analog input wiring is defective.Repair: Repair the wiring or replace the wiring.Proceed to test step 4.Test Step 4. CHECK IF THE DIAGNOSTIC CODE REMAINS
Inspect the harness connectors and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Reset the engine.
Operate the engine.
Check the status of