0334718 JOHNSON PLUG, Fuel conn. hole, 88

Table 1
Diagnostic Trouble Codes for the Oil Pressure Switch
J1939 Code Description Notes
100-2 Engine Oil Pressure : Erratic, Intermittent, or Incorrect When the keyswitch is in the ON position (engine not running), the oil pressure switch circuit should be closed.
This diagnostic code will be active when the Electronic Control Module (ECM) detects the following conditions:
The engine is not running.
The circuit for the oil pressure switch is open.
The warning lamp will come on.
The engine is equipped with an oil pressure switch. While the engine is running and oil pressure is detected, the switch will be open. When no oil pressure is detected, the switch will be closed.
Table 2
Oil Pressure Switch States and Diagnostics Summary
Engine Condition Oil Pressure Switch State Active Diagnostic Code
Not running Closed Normal condition (no oil pressure detected)
Running Open Normal condition (oil pressure detected)
Not running Open 100-2
Running Closed 100-1 Note: If a 100-1 diagnostic code is active, refer to Troubleshooting, "Oil Pressure Is Low" before returning to this procedure.
Illustration 1 g06380128
Schematic diagram for the oil pressure switch circuit
Note: All connectors may not be shown. Refer to the Electrical Schematic for the application for details of any connectors between the oil pressure switch connector and the ECM connectors.
Table 3
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the connector for the oil pressure switch and the engine interface connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".
B. Perform a 30 N (6.7 lb) pull test on each of the wires that are associated with the oil pressure switch in the oil pressure switch connector and the engine interface connector.
C. Check the harness for abrasions and for pinch points from the oil pressure switch back to the ECM.
Note: Do not disconnect the ECM connector at this stage. The ECM can only be disconnected and reconnected 10 times before damage to the harness connector may occur.
Damaged wire or connector
Result: A damaged wire or damaged connector was found.
Repair: Repair the damaged wire or the damaged connector.
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion or of pinch points.
Proceed to Test Step 2.
2. Check for Active or Recently Logged Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position. Do not start the engine.
D. Check for any active or recently logged diagnostic codes. Wait at least 30 seconds for activation of the diagnostic codes.
Diagnostic codes
Result: A 100-1 diagnostic code is recently logged.
This diagnostic code indicates that the oil pressure is low, but can also be caused by a short circuit condition in the oil pressure switch circuit.
Repair: Check for engine oil pressure problems before returning to this procedure. refer to Troubleshooting, "Oil Pressure Is Low".
If the fault is still present, proceed to Test Step 3.
Result: A 100-2 diagnostic code is active.
Proceed to Test Step 6.
Result: A 100-2 diagnostic code is not active. A 100-1 diagnostic code is not recently logged.
An intermittent 100-2 diagnostic code can be caused by turning the keyswitch to the ON position after the engine has recently been stopped or an intermittent fault may exist.
Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" to identify intermittent faults.
3. Create an Open Circuit at the Switch Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the harness connector for the oil pressure switch.
C. Turn the keyswitch to the ON position. Do not start the engine.
D. Use the electronic service tool to check for an active 100-2 diagnostic code. Wait at least 30 seconds for activation of the diagnostic code.
Diagnostic codes
Result: A 100-2 diagnostic code is active with the switch disconnected.
Repair: Replace the oil pressure switch. Refer to Disassembly and Assembly, "Engine Oil Pressure Switch - Remove and Install".
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: A 100-2 diagnostic code is not active with the oil pressure switch disconnected.
Reconnect the harness connector for the oil pressure switch and proceed to Test Step 4.
4. Create an Open Circuit at the Engine Interface Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the engine interface connector.
C. Turn the keyswitch to the ON position. Do not start the engine. Wait at least 30 seconds for activation of the diagnostic codes.
D. Use the electronic service tool to check for an active 100-2 diagnostic code.
Note: Diagnostic codes for all the engine sensors will be active with the engine interface connector disconnected. Ignore all other codes and only look for a 100-2 diagnostic code.
E. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: A 100-2 diagnostic code is active with the engine interface connector disconnected.
The fault is in the wiring between the engine interface connector and the oil pressure switch.
Repair: Replace the faulty wiring.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: A 100-2 diagnostic code is not active with the engine interface connector disconnected.
Reconnect the engine interface connector. Proceed to Test Step 5.
5. Check the Oil Pressure Switch Signal Wire for a Short to Ground
A. Disconnect the P2 connector from the ECM. Thoroughly inspect the P2/J2 connector for damage or corrosion. Refer to Troubleshooting, Electrical Connectors - Inspect for more information.
B. Disconnect the engine interface connector.
C. Use a suitable multimeter to measure the resistance between terminal 22 on the engine interface connector and a suitable ground.
Greater than 1k Ohm
Result: The measured resistance is less than 1k Ohm.
There is a short to ground in the wiring between the engine interface connector and the P2 connector.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The measured resistance is greater than 1k Ohm.
Contact the Dealer Solution Network (DSN).
6. Create a Short at the Switch Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the harness connector for the oil