18598 1 Mercury PIPE PLUG (3/8-18)

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
105-3 Inlet Manifold Temperature Sensor : Voltage Above Normal The engine's Electronic Control Module (ECM) detects signal voltage that is more than 4.8 VDC for one second.
The ECM has been powered for at least three seconds. The code is logged.
The value of the parameter is set to zero.
105-4 Inlet Manifold Temperature Sensor : Voltage Below Normal The ECM detects signal voltage that is less than 0.2 VDC for one second.
The ECM has been powered for at least three seconds.
175-3 Engine Oil Temperature Sensor : Voltage Above Normal The ECM detects signal voltage that is more than 4.8 VDC for one second.
The ECM has been powered for at least three seconds. The code is logged.
The value of the parameter is set to zero.
175-4 Engine Oil Temperature Sensor : Voltage Below Normal The ECM detects signal voltage that is less than 0.2 VDC for one second.
The ECM has been powered for at least three seconds. System OperationUse this procedure to troubleshoot any suspect problems with the following sensors:
Inlet manifold temperature sensor
Engine oil temperature sensorThe sensor signal for the passive sensors is routed to terminal C of each sensor connector. The sensor return for the passive sensors is routed to terminal B of each sensor connector.
Illustration 1 g01341867
Typical schematic
Illustration 2 g01242612
P1 ECM connector
(P1-3) Sensor return (left rail)
(P1-14) "Inlet manifold temperature sensor"
(P1-26) Engine oil temperature sensor
(P1-35) Sensor return (right rail)
Illustration 3 g01341888
Terminal locations for the A-C1/E-C2/E-C1/C-C1 rigid harness
(Terminal B) Sensor return
(Terminal H) Engine oil temperature
Illustration 4 g01341865
Sensor connector
(Terminal C) Sensor signal
(Terminal B) Sensor return
Illustration 5 g01337991
Connector locations
(1) A-C1/E-C2 RH rigid harness connectors
(2) A-C2/J-C2 RH rigid harness connectors
(3) P-C1/A-C90 Connectors for the power distribution panel
(4) P-C2/A-C91 Connectors for the power distribution panel
(5) G-C6/F-C2/F-C1/A-C92 Connectors for a RH Control panel
(6) C-C22 Connection for the P2 ECM connector
(7) C-C15 Connection for the P1 ECM connector
(8) G-C6/F-C2/F-C1/C-C17 Connectors for a LH Control panel
(9) C-C18/TB-C1 Customer connectors
(10) C-C2/J-C1 LH rigid harness connectors
(11) C-C1/E-C1 LH rigid harness connectors Test Step 1. Check for "Active" or "Logged" Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore power to the ECM.
Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Determine if the problem is active and related to one of the following diagnostic codes:
3
4Expected Result:No diagnostic codes are active at this time.Results:
OK - No diagnostic codes are active at this time.Repair: The problem may be intermittent. If the problem is intermittent refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - An active 3 diagnostic code is present. Proceed to Test Step 2.
Not OK - An active 4 diagnostic code is present. Proceed to Test Step 4.Test Step 2. Check for Battery Voltage on the Signal Wire
Measure the voltage on the harness side of the sensor connector between terminal C (signal) and engine ground for the suspect sensor(s). Expected Result:The signal voltage is less than Battery voltage.Results:
OK - The signal voltage is less than battery voltage. Proceed to Test Step 3.
Not OK - The signal voltage is equal to battery voltage.Repair: There is a short in the harness to the +Battery. Repair the wiring.STOPTest Step 3. Create a Short at the Sensor Connector
Disconnect the suspect sensor.
Use a wire jumper in order to create a short between terminal C (signal) and terminal B (sensor return) at the sensor connector.
Restore power to the ECM.
Access the "Active Diagnostic Code" screen on Cat ET. Check for an active 4 diagnostic code for the suspect sensor. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Remove power from the ECM. Expected Result:A 4 diagnostic code is now active for the suspect sensor(s).Results:
OK - A 3 diagnostic code was active before creating the short at the sensor connector. A 4 diagnostic code became active after creating the short at the sensor connector.Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Verify that there are no active diagnostic codes for the sensor. If there are no active diagnostic codes for the sensor, permanently install the new sensor. Clear any logged diagnostic codes.STOP
Not OK - A 3 diagnostic code is still active for the suspect sensor(s). Proceed to Test Step 5.Test Step 4. Create an Open at the Suspect Sensor Connector
Remove power from the ECM.
Disconnect the sensor connector of the suspect sensor(s) with the active 4 diagnostic code.
Restore power to the ECM.
Access the "Active Diagnostic Code" screen on Cat ET. Check for an active 3 diagnostic code. Wait at least 30 seconds in order for the diagnostic codes to become active.
Remove power from the ECM. Expected Result:A 3 diagnostic code is now active for the suspect sensor(s).Results:
OK - A 4 diagnostic code was active before disconnecting the sensor. A 3 diagnostic code became active after disconnecting the sensor.Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Verify that there are no active diagnostic codes for the sensor. If there are no active diagnostic codes for the sensor, permanently install the new sensor. Clear any logged diagnostic codes.STOP
Not OK - A 4 diagnostic code is still active for the suspect sensor. There is a short circuit between the sensor connector and the ECM. Leave the sensor disconnected. Proceed to Test Step 5.Test Step 5. Check the Operation