SENSOR GP-PRESSURE 2490094 - Caterpillar

the electrical power to the ECM. Use Cat ET in order to check for diagnostic codes that are active or recently logged. Expected Result:No diagnostic codes are active or recently logged.Results:
OK - No diagnostic codes are active.Repair: If the engine is running and starting properly at this time, there may be an intermittent problem in a harness or a connector. If you suspect that an intermittent electrical problem exists in the harness or in a connector, refer to Testing and Adjusting, "Electrical Connectors - Inspect" for information that is related to troubleshooting intermittent electrical problems.STOP
Not OK - 168-2 Active - A 168-2 is active or recently logged. The ECM has detected an intermittent problem in the unswitched battery circuit for the ECM. There may be a problem in the battery circuit from the batteries to the ECM. Proceed to Test Step 2.
Not OK - 168-3 Active - A 168-3 is active or recently logged.Repair: There appears to be an overvoltage condition in the unswitched battery circuit for the ECM. There may be a problem with the alternator. Refer to Troubleshooting, "Alternator Problem" for information that is related to troubleshooting problems with the alternator.STOP
Not OK - 168-4 Active - A 168-4 is active or recently logged. There appears to be an undervoltage condition in the unswitched battery circuit for the ECM. There may be a problem with the batteries or the harness. Proceed to Test Step 3.Test Step 2. Check for an Intermittent Condition in the Wiring by Wiggling the Harness and Checking for Active Diagnostic Codes
Ensure that the engine will not crank during this procedure. If an air start system is installed, remove the pressurized air supply from the air start system. Purge any remaining pressurized air from the system.
Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools" for details.
Restore the electrical power to the ECM. Use Cat ET in order to monitor active diagnostic codes or recently logged diagnostic codes during each of the test steps.
Check for an intermittent condition in each section of harness from the starter to the ECM. Place the engine control in the STOP position and perform the following procedure: During each step of this procedure, be sure to check for diagnostic codes that become active or recently logged.
Wiggle the length of harness from the starter to the ECM control box.
Wiggle the length of harness that is on both sides of the connector for the ECM control box.
Wiggle the length of harness that is on both sides of the connector for the engine interface harness.
Check the connections at the connector for the display panel.
Wiggle the harness at the J1/P1 ECM connector. Remove the electrical power from the engine.Expected Result:The 168-2 diagnostic code does not become active or logged during the test.Results:
OK - The 168-2 diagnostic code did not become active or logged during the test.Repair: If the engine is running properly and the engine is starting properly at this time, there may be an intermittent problem in a