F1990 Force HEX CAP SCREW, 1/4 - 20 X 1 5/8

Illustration 1 g01200515
Schematic for the indicator lamps
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g01167488
Engine view (typical example)
(1) J1/P1 ECM connector
Thoroughly inspect connectors (1). Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01200518
P1 terminals for the indicator lamps
(P1-29) "Air Filter Restriction Lamp"
(P1-30) "Start Aid Lamp"
Illustration 4 g01200519
Machine connector
(8) "Air Filter Restriction Lamp"
(18) "Start Aid Lamp"
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the indicator lamps.
Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Check the harness and wiring for abrasions and for pinch points from the indicator lamps to the ECM. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors and wiring appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.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 Lamp
Restore the electrical power to the ECM and monitor the indicator lamps. Expected Result:The indicator lamps turn on for five seconds. Then, the indicator lamps turn off.Results:
OK - The indicator lamps turn on for five seconds. Then, the indicator lamps turn off.Repair: The problem appears to be resolved. The original problem was probably caused by a poor electrical connection. If an intermittent problem is suspected, refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - An indicator lamp does not turn on. Proceed to Test Step 3.Test Step 3. Check the Wiring to the Lamp Socket
Use a test lamp in order to check for voltage at the suspect lamp socket. Connect the test lamp between the suspect lamp terminals.
Restore the electrical power to the ECM and monitor the test lamp. Expected Result:The test lamp illuminates during the first five seconds after the electrical power is returned to the ECM.Results:
OK - The test lamp illuminates during the first five seconds after the electrical power is returned to the ECM.Repair: Replace the bulb.Verify that the repair eliminates the problem.STOP
Not OK - The test lamp did not illuminate during the first five seconds after the electrical power is returned to the ECM. Proceed to Test Step 5.Test Step 4. Check for Electrical Power to the Lamp Socket
Use a test lamp to check for voltage at the suspect lamp socket.
Connect the test lamp between terminal 1 at the suspect lamp socket and engine ground.
Restore the electrical power to the ECM and monitor the test lamp. Expected Result:The test lamp illuminates after the electrical power is returned to the ECM.Results:
OK - The test lamp illuminates after the electrical power is returned to the ECM. Proceed to Test Step 5.
Not OK - The test lamp did not illuminate after the electrical power was returned to the ECM.Repair: Verify that the fuse for the "LH/RH Dash Indicator" is not blown. If voltage is not present at the fuse, refer to the diagnostic functional test Troubleshooting, "Electrical Power Supply Circuit - Test" for the procedure to check the electrical power to the indicator lamps. Refer to Illustration 1.STOPTest Step 5. Bypass the ECM in order to Test the Lamp Circuit
Connect a jumper wire between the terminals at the suspect lamp socket.
Disconnect the J1/P1 connectors.
Remove the wire for the suspect lamp from ECM connector P1. Refer to Table 1 for the appropriate wire terminals.
Table 1
P1 Terminals for the Connection of the Jumper Wire
Indicator Lamp Terminals
"Air Filter Restriction Lamp" P1-29
"Start Aid Lamp" P1-30
Connect a test lamp between the wire that was removed from the ECM connector and engine ground.
Restore the electrical power to the ECM and observe the test lamp. Expected Result:The test lamp turned on.Results:
OK - The test lamp turned on.Repair: If the indicator lamps turn on, there may be a problem with the ECM. It is unlikely that the ECM has failed. Exit this procedure and perform this entire procedure again.If the problem is not resolved, replace the ECM. Refer to electronic troubleshooting Troubleshooting, "Replacing the ECM".STOP
Not OK - The test lamp does not turn on for five seconds.Repair: Check for an open in the wire between the indicator lamp and the ECM. STOP