0323791 JOHNSON BRACKET, Starboard

Illustration 1 g01064548
The "Engine Running Output" activates when the engine is running. This can be used to prevent the engagement of the starting motor while the engine is running. The Engine Control Module (ECM) can be connected to a relay that disables the starter. The relay is normally closed so cranking can be achieved immediately at powerup. During cranking, the ECM energizes the "Engine Running Output" once engine rpm reaches 50 rpm below low idle. The output is de-energized when the engine speed falls by 100 rpm below the programmed low idle. The low idle rpm is programmable. The range for low idle is between 600 rpm and 750 rpm.
Illustration 2 g01064659
Schematic for engine running output circuit
Illustration 3 g01064550
Terminal locations at the ECMTest Step 1. Inspect the Electrical Connectors and the Wiring
Thoroughly inspect ECM vehicle harness connector J1/P1, and the firewall bulkhead connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on terminal 28, terminal 34, or terminal 40 in the ECM connector.Refer to Illustration 3.
Check the allen head screws at each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.
Check the harness and wiring for abrasion and for pinch points from the sensor to the ECM.Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring should be free of corrosion, of abrasion or of pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair the wiring or replace the wiring, if necessary. Repair the connectors or replace the connectors, if necessary. Ensure that all of the seals are in the proper place. Ensure that all of the connectors are connected properly. Verify that the repair eliminates the problem.STOPTest Step 2. Check the Configuration Parameters
Connect the Caterpillar Electronic Technician (ET) to the cab data link connector.
Turn the keyswitch to the ON position.
Access the "Customer Specified Parameter Screen" in order to make sure that the ECM is programmed to use the "Engine Running Output".
Ensure that the "Engine Running Output" circuit is connected to the programmed output.Expected Result:The circuit is connected to the correct ECM terminal that is selected for the "Engine Running Output".Results:
OK - Proceed to Test Step 3.
Not OK - Update the customer specified parameter in order to match the correct output terminal.STOPTest Step 3. Use Cat ET Check for an Audible Click at the Relay
Turn the keyswitch to the ON position.
Access the "Engine Running Output Special Test" on ET. The "Engine Running Output Special Test" will enable the "Engine Running Output" when the test is active.
Begin the "Engine Running Output Special Test" and listen for the relay to click. You may need to be near the engine in order to hear the click.Expected Result:The relay will activate when the test is turned on.Results:
OK - The ECM and vehicle components are operating correctly.STOP
Not OK - Proceed to Test Step 4.Test Step 4. Use ET to Check for Proper Operation of the ECM
Connect ET to the cab data link connector.
Turn the keyswitch to the OFF position.
Disconnect the ECM vehicle harness connector J1/P1.
Connect a 40-pin breakout T between ECM connectorsJ1 and P1.
At the breakout T, connect a voltage test lamp to terminal 5 (-Battery) and the terminal that is programmed for "Engine Running Output". Refer to Illustration 2.
Turn the keyswitch to the ON position.
Access the appropriate "Engine Running Output Special Test" on ET.
Cycle the corresponding "Engine Running Output Special Test" to the ON position and to the OFF position and watch the voltage test lamp.
Stop the special test.Note: A multimeter cannot be used in place of the voltage test lamp when the ECM outputs are being tested.Expected Result:The voltage test lamp turns on when the"Engine Running Output Special Test" is active. The voltage test lamp also turns off when the "Engine Running Output Special Test" is not active.Results:
OK - The ECM is OK. The problem is in the vehicle wiring. Inspect the vehicle wiring and then repair the vehicle wiring. Otherwise, send the vehicle to the OEM dealer for repair. Verify that the original condition is resolved.STOP
Not OK - Temporarily connect a test ECM. Use the "Engine Running Output Special Test" on Cat ET to check the ECM. If the problem is resolved with the test ECM, install the suspect ECM. If the problem returns with the suspect ECM, replace the ECM. Verify that the repair eliminates the problem.STOP