0308070 JOHNSON VALVE,Vernatherm

Illustration 1 g01195854
Schematic for the switch circuit
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the engine ECM.
Illustration 2 g01186024
Location of the J1/P1 ECM connectors (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connectors and the connectors for each switch. Also inspect each of the machine connectors that are in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01243917
Terminal location at the P1 ECM connector for the right brake pedal switch
(P1-5) Digital return
(P1-44) Right brake pedal switch (N/O)
(P1-45) Right brake pedal switch (N/C)
Illustration 4 g01195660
Connector for the right brake pedal switch
(A) Digital return
(B) Right brake pedal switch (N/O)
(C) Right brake pedal switch (N/C)
Perform a 45 N (10 lb) pull test on each of the wires for the suspect switch.
Check the torque of the allen head screw on each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the switch back to the ECM. Expected Result:All of the 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:
OK - The harness and the connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. 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 Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore the electrical power to the engine ECM. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen for an active code that relates to one of the switches. Toggle the suspect switch as you monitor Cat ET for the active diagnostic code.
Remove electrical power from the engine ECM. Expected Result:A diagnostic code that is related to one of the switches is not active.Results:
OK - A diagnostic code that is related to one of the switches does not become active.Repair: The switches are operating normally. There may be an intermittent problem in the wiring harness or in a connector. Check the wiring harness and the connectors for an intermittent electrical problem. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A diagnostic code that is related to the right brake pedal switch is active. Proceed to Test Step 3.Test Step 3. Create a short at the Connector for the Suspect Switch and Check for Diagnostic Codes
Disconnect the connectors for the suspect switch.
Fabricate a jumper wire that is long enough to connect two terminals at the connector for the suspect switch. Crimp a connector pin to both ends of the jumper wire.
Install the jumper wire between the terminals for switch (N/C) and digital return on the harness side of the connector for the suspect switch.
Restore the electrical power to the engine ECM. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen on Cat ET for an active code that relates to the suspect switch. Also use Cat ET to check the status of the switch. The correct switch status will be "Released".
Remove electrical power from the engine ECM.
Install the jumper wire between the terminal for switch (N/O) and digital return on the harness side of the connector for the suspect switch.
Restore the electrical power to the engine ECM. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen on Cat ET for an active code that relates to the suspect switch. Also use Cat ET to check the status of the switch. The correct switch status will be "Depressed".
Remove electrical power from the engine ECM. Expected Result:There are no active diagnostic codes and