LOCK 2S7066 - Caterpillar

Use this procedure to troubleshoot any suspect problems with the engine indicator lamps.The indicator lamps are activated by the Electronic Control Module (ECM) in order to inform the operator of various engine conditions. When the keyswitch is placed in the ON position, the diagnostic lamp and the warning lamp are illuminated by the ECM for a brief period.The ECM provides a high side driver for all of the lamp outputs. The most likely cause of a problem with an indicator lamp is the bulb. The next most likely cause is a problem with a wire or with a connector. The least cause is a problem with the ECM.Note: An override feature is available in Caterpillar Electronic Technician (ET) for each of the lamp circuits. The override can be used to troubleshoot the lamp circuits.Note: There are configuration parameters that are associated with the low coolant level lamp and the maintenance indicator lamp. Ensure that these parameters are configured correctly prior to troubleshooting the lamp circuits. Refer to Troubleshooting, "Configuration Parameters" for information that is related to the configuration of the lamp circuits.
Table 1
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM.
B. Thoroughly inspect any of the connectors that are associated with the lamp circuits. Refer to the Schematic of the engine for connector locations. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of the wires for the lamp circuits.
D. Check the torque of the allen head screw on the ECM connectors and the engine interface connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
E. Check the harness and the wiring for abrasion and for pinch points from the dash display back to the ECM.
Connectors
Results: The harness and connectors appear to be in good repair.
Proceed to Test Step 2
Results: The connectors and/or wiring need repair.
Repair The wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are coupled. Verify that the repair eliminates the problem.
2. Check for Proper Operation of the Lamp Circuits
A. Connect Cat ET to the service tool connector.
B. Restore electrical power to the ECM.
C. Select the "Override Parameters" option from the "Diagnostic Tests" on Cat ET.
D. Use the correct override parameter to power the circuit for the suspect lamp.
E. Remove electrical power from the ECM.
Lamp circuits
Results: The suspect lamp illuminates when the override is on.
Repair: There does not appear to be a problem with the lamp circuit at this time. The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect"
Results: The suspect lamp does not illuminate when the override is on.
Inspect the lamp and the lamp socket for the suspect circuit. If either of the components are questionable, replace the component. Retest the circuit. If the problem persists or if the components of the lamp