0321690 JOHNSON COVER,Thermostat

Illustration 1 g00863820
This is a typical schematic for the "PTO Engine RPM Set Speed Input A" switch circuit.
The return wire may be connected to P1-3, P1-5, or P1-18.
Illustration 2 g00932375
This is a typical schematic for the "PTO Engine RPM Set Speed Input B" switch circuit.
The return wire may be connected to P1-3, P1-5, or P1-18.
Illustration 3 g01152269
Pin locations on ECM connector
(P1-5) AP sensor/switch common
(P1-7) Input 4
(P1-23) Input 19
(P1-46) Input 7 Test Step 1. Inspect Electrical Connectors and Wiring
Thoroughly inspect the ECM vehicle harness connector J1/P1, the connectors, and the firewall bulkhead connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the suspect switch circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and the wiring for abrasion and for pinch points from the battery to the ECM. Then, check from the ignition key switch to the ECM. Refer to Illustration 3 for terminal locations for the ECM.Expected Result:All 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 - Proceed to Test Step 2.
Not OK - Repair: Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected.Verify that the repair eliminates the problem.STOPTest Step 2. Use Caterpillar Electronic Technician (ET) to Check the Status of the "PTO Engine RPM Set Speed Input A and PTO Engine RPM Set Speed Input B"
Connect Cat ET to the data link connector.
Turn the ignition key switch to the ON position.
Operate the switch in the ON and OFF positions.
View the switch status on Cat ET.
If the "PTO Engine RPM Set Speed Input A" status indicates "Not Installed", then the parameter has not been programmed. If the "PTO Engine RPM Set Speed Input B" status indicates "Not Installed", then the parameter has not been programmed. Expected Result:The status screen indicates "ON" if the switch is turned on. The status screen indicates "OFF" if the switch is off.Results:
OK - The switch is operating normally. Continue troubleshooting if the original condition is not resolved.STOP
Not OK - The ECM is not reading the switch status change. Proceed to Test Step 3.Test Step 3. Check the Switch Circuit for the ECM
Illustration 4 g01152272
Pin locations on breakout T
(5) AP sensor/switch common
(7) Input 4
(23) Input 19
(46) Input 7
Turn the ignition key switch to the OFF/RESET position.
Install a breakout T to the ECM vehicle harness connector J1/P1.
Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wire.
Insert the jumper wire into the suspect switch socket of the breakout T. Connect the other end of the jumper wire to terminal 5 (AP Sensor/Switch Common) in the breakout T.
Verify that Cat ET is connected to the data link connector.
Turn the ignition key switch to the ON position.
Alternately remove the jumper wire and then insert the jumper wire from terminal 5. At the same time, monitor the status screen on Cat ET. Expected Result:The switch status changes to "ON" with the jumper wire in place. The switch status changes to "OFF" when the jumper wire is removed.Results:
OK - The ECM is functioning properly at this time. Proceed to Test Step 4.
Not OK - The ECM is not functioning properly.Repair: Perform the following repair:
Temporarily connect a test ECM. Only connect ECM harness J1/P1.
Recheck for an +5 V diagnostic code when the engine harness is disconnected.
If the problem is resolved with the test ECM, reconnect the suspect ECM.
If the problem returns with the suspect ECM, replace the ECM. STOPTest Step 4. Insert a Jumper Wire at the Switch
Turn the ignition key switch to the OFF/RESET position.
Reconnect the ECM vehicle harness connector J1/P1.
Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wire.
Insert the jumper wire between the two switch terminals.
Turn the ignition key switch to the ON position.
Alternately remove the jumper wire and then insert the jumper wire at the switch terminals. At the sa