0300314 JOHNSON PLUG

Illustration 1 g01513883
Schematic for the throttle switch
Illustration 2 g01513958
Terminal locations at the throttle switch
(34) Throttle return
(49) Throttle switch (high idle parity)
(50) Throttle switch (high idle)
(51) Throttle switch (low idle parity)
(52) Throttle switch (low idle)
Illustration 3 g01250541
Terminal locations at the throttle switch
(Terminal 1) Throttle switch (low idle)
(Terminal 2) Throttle return
(Terminal 3) Throttle switch (high idle parity)
(Terminal 4) Throttle switch (low idle parity)
(Terminal 5) Throttle return
(Terminal 6) Throttle switch (high idle) Test Step 1. Inspect Electrical Connectors and Wiring
Remove the electrical power from the ECM.
Thoroughly inspect the J1/P1 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and at the connector for the throttle switch.
Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for corrosion, for abrasion, and for pinch points from the throttle switch 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 harness and connectors 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.If necessary, perform a "Wiggle Test" by using the electronic service tool in order to identify intermittent connections.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check "Throttle Cab Switch Position" on the Electronic Service Tool
Connect the electronic service tool to the diagnostic connector.
Restore the electrical power to the ECM.
Observe the status of the throttle switch and the throttle inputs on the electronic service tool while you operate the throttle switch in each position. Expected Result:The throttle switch is functioning correctly.Results:
OK - The throttle switch is functioning correctly at this time.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the fault is intermittent.STOP
Not OK - The throttle switch is not functioning correctly at this time. Record the suspect input. Proceed to Test Step 3.Test Step 3. Jumper the Switch Input at the Throttle Switch Connector
Disconnect the throttle switch connector.
Observe the status of the suspect throttle input on the electronic service tool.
Use a suitable jumper wire to short terminal 5 to the terminal for the suspect throttle input at the throttle switch connector .
Observe the status of the suspect throttle input on the electronic service tool.
Remove the jumper wire. Expected Result:The status of the suspect throttle input is OFF when the throttle switch connector is disconnected. The status is ON when the jumper wire is installed.Results:
OK - The status is correct. The harness and the ECM are OK.Repair: Replace the throttle switch.Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOP
Not OK - The status is not correct. Proceed to Test Step 4.Test Step 4. Check for Shorts in the Harness
Remove the electrical power from the ECM.
Disconnect the P1 ECM connector and disconnect the throttle switch connector.
Measure the resistance between engine ground and the terminal for the suspect throttle input at the throttle switch connector.
Measure the resistance between the terminal for the suspect throttle input at the throttle switch connector and the remaining terminals at the connector. Expected Result:Resistance is greater than 20,000 Ohms for each reading.Results:
OK - The resistance is greater than 20,000 Ohms for each reading. Proceed to Test Step 5.
Not OK - The resistance is not greater than20,000 Ohms for each reading.Repair: Repair the circuit.Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 5. Check Resistance through the Harness
Use a jumper wire to short terminal 5 to the terminal of the suspect throttle input at the throttle switch connector .
Measure the resistance between P1-34 and the terminal for the suspect throttle input at the J1/P1 ECM connector. Expected Result:The resistance should be less than 10 Ohms.Results:
OK - The resistance is less than 10 Ohms. Proceed to Test Step 6.
Not OK - The resistance is not less than 10 Ohms. There is an open circuit or excessive resistance in the harness.Repair: Repair the circuit.Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 6. Check the Harness and the ECM
Remove the electrical power from the ECM.
Disconnect the J1/P1 ECM connector and remove the wire for the suspect throttle input.
Reconnect all of the connectors.
Restore the electrical power to the ECM.
Observe the status of the suspect throttle input on the electronic service tool.
Remove the electrical power from the ECM.
Disconnect the J1/P1 ECM connector and remove the wire from P1-34.
Fabricate a jumper wire with pins at both ends. Insert the jumper wire at terminal P1-34 and at the terminal for the suspect throttle input.
Reconnect all of the connectors.
Restore the electrical power to the ECM. Note: Additional diagnostic codes will be generated because P1-34 will no longer be connected to other sensors and switches. Ignore the codes and clear the codes when you complete this test.
Observe the status of the suspect throttle input on the electronic service tool.
Remove the electrical power from the ECM.
Remove the jumper wire from the J1/P1 ECM connector and reconnect all wires and connectors. Expected Result:The status of the suspect throttle input is OFF when the throttle input is open. The status is ON when the jumper wire is installed.Results:
OK - The status is correct. There is a fault in the harness between the ECM and the throttle switch.Repair: Repair the circuit.Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOP