System Operation Description:
Use this procedure under the following situation:
The Engine Shutdown Output Circuit is suspected of incorrect operation.
The following background information is related to this procedure:
Shutdown Output
The “Engine Shutdown Output” can be programmed to J1/P1:10, J1/P1:12, or J1/P1:13.
The “Engine Shutdown Output” will function on the corresponding Output that is selected:
• ECM Connector J1/P1 Terminal 10
• ECM Connector J1/P1 Terminal 12
• ECM Connector J1/P1 Terminal 13
The shutdown output allows the ECM to shut down portions of the vehicle’s electrical system at shutdown. This reduces the consumption of electrical power (battery draw) after the truck is shut down. The system activates a normally open relay (Shutdown Output Relay) when the engine begins running. This permits the driver to turn the ignition key switch to the OFF position without causing the engine to shutdown. When the Idle Shutdown Timer completes the countdown and the Idle Shutdown Timer shuts down the engine, the ECM turns off the relay. This interrupts the power to the ECM. The current draw on the batteries is then dependent on the items that are not powered through the Shutdown Output Relay Circuit.
Test Step 1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect ECM vehicle harness connector J1/P1, and the firewall bulkhead connector. Refer to Troubleshooting, “Electrical Connectors – Inspect” for details.
B. Perform a 45 N (10 lb) pull test on terminal 10, terminal 12, or terminal 13 in the ECM connector. Refer to Illustration 94.
C. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).
D. Check the harness and wiring for abrasion and pinch points from the sensor to the ECM.
Expected Result:
All connectors, pins, and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion, or 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. STOP.
Test Step 2. Check the Programmable Parameters
A. Connect the Caterpillar Electronic Technician (ET) to the cab data link connector.
B. Turn the ignition key switch to the ON position.
C. Access the customer specified parameter screen in order to make sure that the ECM is programmed to use the engine shutdown output.
D. Ensure that the circuit for the engine shutdown output is connected to the programmed output.
Expected Result:
The circuit is connected to the correct ECM terminal that is selected for the “Engine Shutdown Output”.
Results:
• OK – Proceed to Test Step 3.
• Not OK – Update the customer specified parameter in order to match the correct output terminal. STOP.
Test Step 3. Connect ET in order to Check the Relay
A. Turn the ignition key switch to the ON position.
B. Access the “Engine Shutdown Output Special Test” on ET. The “Engine Shutdown Output Special Test” will enable the “Engine Shutdown Output” when the test is active.
C. While you listen for the relay to click, begin the “Engine Shutdown Output Special Test”.
Note: You may need to be near the relay in order to hear the click.
Expected Result:
The relay activates when the special test is enabled.
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 the ECM
A. Connect ET to the cab data link connector.
B. Turn the ignition key switch to the OFF position.
C. Disconnect the ECM vehicle harness connector J1/P1.
D. Connect a 70 Terminal Breakout T between connectors J1 and P1.
E. If the “Engine Shutdown Output” is programmed to J1/P1:10, connect a voltage test lamp to terminal 10 (Output 2) and terminal 65 (-Battery) of the breakout T.
F. If the “Engine Shutdown Output” is programmed to J1/P1:12, connect a voltage test lamp to terminal 12 (Output 3) and terminal 65 (-Battery) of the breakout T.
G. If the “Engine Shutdown Output” is programmed to J1/P1:13, connect a voltage test lamp to terminal 13 (Output 4) and terminal 65 (-Battery) of the breakout T.
H. Turn the ignition key switch to the ON position.
I. Access the “Engine Shutdown Special Test” on ET.
J. While you monitor the voltage test lamp, cycle the “Special Test” from the ON position to the OFF position back to the ON position.
K. Stop the “Special Test”.
Note: A multimeter can not 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 Shutdown Output Special Test” is active. The voltage test lamp turns off when the “Engine Shutdown Output Special Test” is not active.
Results:
• OK – The ECM is operating correctly. 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 “Engine Shutdown Output Special Test” on 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.
