LEVER GP 3727459 - Caterpillar

Illustration 1 g00812427
Schematic for the circuit for the compression brake lampTest Step 1. Inspect the Bulb for the Compression Brake Lamp
Turn the keyswitch to the "OFF/RESET" position.
Remove the bulb. Inspect the bulb for damage and for a broken filament.Expected Result:The bulb should be free from apparent damage. The filament should be intact.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Replace the bulb.Verify that the repair eliminates the problem.STOPTest Step 2. Inspect Electrical Connectors And Wiring.
Illustration 2 g00812521
Terminal locations for ECM connector P1
Thoroughly inspect ECM machine harness connector J1/P1, the firewall bulkhead connector, and the compression brake lamp (terminal 10). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM machine harness connector that are associated with the compression brake lamp.
Check the ECM machine harness connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasions and for pinch points from the battery 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 3.
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.STOPTest Step 3. Check For Normal Operation Of The Lamp.
Connect ET to the service tool connector.
Turn the keyswitch to the ON position.
Access the screen for the overrides on ET.
Activate the "Jake Brake Low/High" or the "Jake Brake Med/High" override.
Monitor the compression brake lamp.
The lamp should turn on when the override is active.
Deactivate the override.
The lamp should turn off when the override is deactivated.Expected Result:The compression brake lamp turns on when the override is activated. The compression brake lamp turns off when the override is deactivated.Results:
Yes - The compression brake lamp appears to operating correctly at this time.STOP
No - Proceed to Test Step 4.Test Step 4. Check the Harness for a Short to Ground
Illustration 3 g00812582
Terminal locations to check for short to ground
Disconnect ECM machine harness connector J1/P1.
Remove the bulb for the compression brake lamp from the socket.
Measure the resistance between P1:10 (compression brake lamp) and the following terminals:
P1:3 (analog return)
P1:61 (-battery)
P1:63 (-battery)Expected Result:The resistance should be greater than 20,000 Ohms for each reading.Results:
OK - The circuit is not shorted to ground. Proceed to Test Step 5.
Not OK - Repair: Wire 454-GN (compression brake lamp) is shorted to ground through one of the following wires in the harness:
P1:3 (analog return)
P1:61 (-battery)
P1:63 (-battery)Repair the circuit. Refer to the Electrical Schematic for more information.Verify that the repair eliminates the problem.STOPTest Step 5. Check the Harness for a Short to +Battery
Illustration 4 g00812762
Terminal locations to check for a short to +battery
Disconnect ECM machine harness connector J1/P1.
Ensure that the bulb for the compression brake lamp is not installed.
Measure the resistance between P1:10 (compression brake lamp) and the following terminals:
P1:2 (analog power)
P1:48 (unswitched +battery)
P1:52 (unswitched