HOUSING-COMPRESSOR 1W0442 - Caterpillar

Conditions Which Generate This Code:This diagnostic code is usually associated with EUI applications. The CID 0590 failure means that the engine electronic control module has stopped responding to the periodic requests for information from the GSC+.Note: This diagnostic code may occur on an MUI application. The diagnostic code is caused by an incorrectly programmed P023 setpoint. For MUI applications, the setpoint P023of GSC+ must be set to 0. Reprogram the setpoint and other GSC+ setpoints. See Systems Operation, "Engine/Generator Programming OP5-0".Test Step 1. CHECK THE CAT DATA LINK
Turn the ECS to OFF/RESET position.
Disconnect the contacts 19 and 20 of the CAT data link from the GSC+.
Disconnect the contacts 13 and 14 of the CAT data link from the ECM.
Measure the resistance between contact 19 of the GSC+ and contact 14 of the ECM.
Measure the resistance between contact 20 of the GSC+ and contact 13 of the ECM.Expected Result:The resistance for both measurements is less than 5 ohms.Results:
OK - The resistance for both measurements is less than 5 ohms. The circuit is correct. The ECM has failed.Repair: It is unlikely that the ECM has failed. See Troubleshooting, SENR1003, "3500B EPG Engines" or Troubleshooting, RENR2227, "3406E EPG Engines" prior to replacing the ECM. Clear the diagnostic code from the fault log after troubleshooting is complete. The GSC+ is usually programmed to treat a CID 590 diagnostic code as an "alarm fault". Setpoint P04 is 0. If the GSC is programmed to treat this code as a shutdown fault, setpoint P04 is 1. Then, it is not necessary to press the "alarm codes" key in order to see the diagnostic code. The diagnostic code is automatically shown on the upper display. Stop.
NOT OK - The resistance for both measurements is greater than 5 ohms. The circuit is not correct.Repair: Repair the wiring of the CAT data link or replace the wiring of the CAT data link.Clear the diagnostic code from the fault log after troubleshooting is complete. The GSC+ is usually programmed to treat a CID 590 diagnostic code as an "alarm fault". Setpoint P04 is 0. If the GSC is programmed to treat this code as a shutdown fault, setpoint P04 is 1. Then, it is not necessary to press the "alarm codes" key in order to see the diagnostic code. The diagnostic code is automatically shown on the upper display. Stop.