LINK & BEARING AS 5087678 - Caterpillar

Illustration 1 g01342633
AWD lamp circuitThe all wheel drive (AWD) indicators are controlled by the AWD ECM. The circuits for the LED are not monitored by the ECM for diagnostics. The power for the circuits of the LED is supplied through the 15 amp control fuse for the AWD ECM. Conditions that could cause an LED indicator to be OFF when the machine is in AWD mode are listed below:
Supply fuse open
Supply circuit is open or has a poor connection
Failed LED
Failed ECMTest Step 1. CHECK THE POWER CIRCUIT FUSE FOR AN OPENNote: The fuse of the AWD ECM also supplies system power to the AWD ECM. Verify that the AWD ECM fuse is not open. However, a fuse open condition would be unlikely, if the fuse was open, the AWD ECM would not function.
Turn off the disconnect switch and the keyswitch.
Pull the AWD ECM fuse out of the fuse holder.
Check the fuse for an open.Expected Result:The fuse is not open.Results:
OK - The fuse is not open.Repair: Reinstall the fuse. Proceed to Test Step 2.
NOT OK - The fuse is open.Repair: Replace the fuse. STOPTest Step 2. CHECK THE HARNESS FOR AN OPENThe disconnect switch and keyswitch remain off.
Unplug the indicator from the harness.
Check for an open circuit between the following points.
Indicator lamp (wire 155-RD) and the fuse
Indicator lamp (wire M901-YL) and contact J2-10
Indicator lamp (wire M902-OR) and contact J2-09Expected Result:Resistance is less than 5 ohms. Results:
OK - Resistance is less than 5 ohms. The circuits are not open. Proceed to Test Step 3.
NOT OK - Resistance is greater than 5 ohms.Repair: Repair or replace the harness.STOPTest Step 3. CHECK THE LED INDICATOR LAMPDisconnect switch and keyswitch remain off.
Connect the harness to the indicator lamp.
Remove the AWD ECM J2 connector from the AWD ECM.
Use a 151-6320 Removal Tool to remove the involved LED circuit wire from the AWD ECM J2-9 or J2-10 connector.Note: J2-9 contact, wire M902-OR if the AWD System Indicator LED is not illuminating. J2-10 contact, wire M901-YL if the AWD Engaged Indicator LED is not illuminating.
Connect one end of a jumper wire to the disconnected LED circuit wire. Connect the other end of the jumper wire to a good frame ground.
Turn on disconnect switch and the keyswitch.Expected Result:The LED indicator illuminates with the jumper wire connected to frame ground.Results:
OK - The LED indicator illuminates with the jumper wire connected to frame ground. The LED and the circuit wire are operating correctly. The ECM may have failed, however, ECM failure is unlikely.Repair: Verify that the LED indicator is supposed to be ON. Exit this procedure and perform this procedure again. If the cause of the problem is not found, contact the Technical Communicator at your Cat® dealer.If ECM replacement is required, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOP
NOT OK - The LED indicator does not illuminate with the jumper wire connected to frame ground. The LED has failed.Repair: Replace the LED.STOP