PIPE AS-EXHAUST 4924567 - Caterpillar

Use this procedure to determine if the fast idle lamp is operating properly.Output 8 or output 9 can operate as a fast idle lamp or a wait to start lamp. The parameter "Fast Idle Lamp" can be programmed to "J1/P1:31" output 9, to "J1/P1:21" output 8, or to "None".Electrical Connections of the LampOne terminal of the lamp must be connected to battery voltage through the vehicle wiring. The other terminal is connected to the Engine Control Module (ECM) at the vehicle harness connector P1-21 or P1-31.
Illustration 1 g00834354
Schematic for the fast idle enable switch
Test Step 1. Inspect Electrical Connectors and Wiring
Illustration 2 g01151114
Pin locations on ECM connector
(P1-21) Output 8
(P1-31) Output 9
Thoroughly inspect ECM vehicle harness connector J1/P1, the firewall bulkhead connector, and the terminals for the fast idle lamp. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the fast idle lamp.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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 are free of corrosion, of abrasion and of pinch points.Results:
Yes - The wiring is OK. Proceed to Test Step 2.
No - The wiring is not OK.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Normal Operation of the Fast Idle Lamp
Verify that a fast idle enable switch is installed.
Connect Caterpillar Electronic Technician (ET) to the cab data link connector.
Turn the ignition key switch to the ON position.
Access the Cat ET status screen. Verify that the following switches indicate the correct status:
The service brake switch 1 is off.
The service brake switch 2 is off.
The neutral switch is on.
The clutch switch is off.If any of the switches do not display the indicated status, fast idle will not activate.
Use the Cat ET status screen to monitor the fast idle switch and the fast idle rpm.
Depress the fast idle switch while the status of the fast idle enable switch is being observed. Also observe the fast idle lamp. Release the fast idle switch. The fast idle lamp should turn on when the fast idle switch is pressed and released.
Depress the service brake pedal. The fast idle lamp should turn off when the service brake is applied. Expected Result:The switch status changes per the above information. The fast idle lamp turns on and the fast idle lamp turns off per the description above.Results:
Yes - The fast idle lamp is operating normally.STOP
No - The ECM is not reading the switch status change. Proceed to Test Step 3.Test Step 3. Test the Fast Idle Lamp Circuit
Illustration 3 g01151119
Pin locations on ECM connector
(P1-21) Output 8
(P1-31)