C32 Marine Engines Transmission Oil Temperature Sensor Open or Short Circuit - Test Caterpillar


Transmission Oil Temperature Sensor Open or Short Circuit - Test
`
C32 Marine Engines [RENR9303]
ELECTRICAL AND STARTING SYSTEM
SENSOR GP

System Operation Description:

Use this procedure to troubleshoot any suspect problems with the marine transmission oil temperature sensor.

This procedure covers the following diagnostic codes:

  • 177-03 Transmission Oil Temperature open/short to +batt

  • 177-04 Transmission Oil Temperature short to ground

Pull-up Voltage

The ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage in order to detect an open in the signal circuit. When the ECM detects the presence of a voltage that is above a threshold on the signal wire, the ECM will generate a -03 diagnostic code.

If the sensor is disconnected at the sensor connector, the presence of pull-up voltage at the sensor connector indicates that the signal wire and the return wire from the sensor connector to the ECM are good.

If the sensor is disconnected at the sensor connector, the absence of pull-up voltage at the sensor connector indicates an open in the signal wire, an open in the return wire, or a short to ground.

If the sensor is disconnected at the sensor connector and the voltage on the signal wire at the sensor connector is different from pull-up voltage, the signal wire is shorted to another wire in the harness.




Illustration 1g01134360

Schematic for the marine transmission oil temperature sensor

Test Step 1. Inspect the Electrical Connectors and the Wiring

  1. Turn the keyswitch to the OFF position.



    Illustration 2g01130316

    Engine components that are associated with the marine transmission oil temperature sensor

    (1) J137/P137 connector for the marine transmission oil temperature sensor

    (2) J2/P2 ECM connectors

  1. Thoroughly inspect connectors (2). Inspect the connectors for the sensor (1). Refer to Troubleshooting, "Electrical Connectors - Inspect".



    Illustration 3g01134390

    P2 terminals that are associated with the marine transmission oil temperature sensor

    (P2-17) Return

    (P2-27) Marine transmission oil temperature

    (P2-72) +5 VDC




    Illustration 4g01134372

    J137 harness connector for the marine transmission oil temperature sensor

    (A) Supply

    (B) Return

    (C) Signal

  1. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the marine transmission oil temperature sensor.

  1. Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.

  1. Check the harness and wiring for abrasions and for pinch points from the marine transmission oil temperature sensor 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 connectors and wiring are OK. Proceed to Test Step 2.

  • Not OK - There is a problem in 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.

    STOP

Test Step 2. Check for Active Diagnostic Codes

  1. Connect the AVSpare Electronic Technician (ET) to the service tool connector.

  1. Turn the keyswitch to the ON position.

  1. Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.

    Note: Wait at least 15 seconds in order for the diagnostic codes to become active.

  1. Look for an 03 diagnostic code or an 04 diagnostic code for the marine transmission oil temperature sensor.

Expected Result:

No diagnostic codes are active.

Results:

  • OK - No diagnostic codes are active.

    Repair: The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect" for additional information.

    STOP

  • Not OK - An 04 diagnostic code is active. Proceed to Test Step 3.

  • Not OK - An 03 diagnostic code is active. Proceed to Test Step 5.

Test Step 3. Check the Supply Voltage at the Harness Connector for the Sensor

  1. Turn the keyswitch to the OFF position.

  1. Disconnect the harness connector for the sensor.

  1. Turn the keyswitch to the ON position.

  1. Measure the voltage between terminals A (5 V analog supply) and B (sensor return) at the harness connector for the sensor.

  1. Turn the keyswitch to the OFF position.

  1. Connect the sensor's harness connectors.

Expected Result:

The voltage is 5.0 ± 0.2 VDC.

Results:

  • OK - The voltage is 5.0 ± 0.2 VDC. The voltage is correct. Proceed to Test Step 4.

  • Not OK - The voltage is not 5.0 ± 0.2 VDC. The voltage is incorrect.

    Repair: Perform the diagnostic functional test Troubleshooting, "Analog Sensor Supply Circuit - Test".

    STOP

Test Step 4. Disconnect the Sensor in Order to Create an Open Circuit

  1. Turn the keyswitch to the OFF position.

  1. Disconnect the harness connector for the sensor.

  1. Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.

  1. Access the "Active Diagnostic Codes" screen on Cat ET and check for an active 03 diagnostic code for the sensor.

  1. Turn the keyswitch to the OFF position.

Expected Result:

An 03 diagnostic code is now active for the sensor.

Results:

  • OK - An 04 diagnostic code was active before disconnecting the sensor. An 03 diagnostic code became active after the sensor was disconnected.

    Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the transmission. 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.Verify that the repair eliminates the problem.

    STOP

  • Not OK - The 04 diagnostic code is still present. Leave the sensor disconnected. Proceed to Test Step 8.

Test Step 5. Check the Pull-up Voltage at the Sensor Connector

  1. Disconnect the harness connector for the sensor.

  1. Turn the keyswitch to the ON position.

  1. Measure the voltage between terminals C (signal) and B (return) at the harness connector.

  1. Turn the keyswitch to the OFF position.

Expected Result:

The voltage is 5.5 ± 0.5 VDC.

Results:

  • OK - The voltage is 5.5 ± 0.5 VDC. The correct pull-up voltage is present at the harness connector.

    Repair: The open circuit is in the sensor or the wire between the sensor and the harness connector. Replace the sensor. Do not install the sensor in the transmission. Verify that no diagnostic codes are active for the suspect sensor before you permanently install the sensor.

    STOP

  • Not OK - The voltage is not 5.5 ± 0.5 VDC. Proceed to Test Step 6.

Test Step 6. Check the Signal Wire for a Short Circuit

  1. Turn the keyswitch to the OFF position.

  1. Disconnect the J1/P1 and J2/P2 connectors.

  1. Measure the resistance between terminal P2-27 and all of the remaining terminals on the P2 connector.

  1. Measure the resistance between terminal P2-27 and all of the terminals on the P1 connector.

  1. Measure the resistance between terminal P2-27 and the engine ground.

  1. Connect the J1/P1 and J2/P2 connectors.

Expected Result:

Each check of the resistance indicates an open circuit.

Results:

  • OK - Each check of the resistance indicates an open circuit. Proceed to Test Step 7.

  • Not OK - At least one check of the resistance does not indicate an open circuit. There is a problem with the wiring. There may be a problem with a connector.

    Repair: Repair the wiring and/or the connectors. Replace parts, if necessary.Verify that the original problem is resolved.

    STOP

Test Step 7. Create a Short at the Harness Connector

  1. Turn the keyswitch to the OFF position.

  1. Install a jumper wire between terminals B and C on the harness connector for the sensor.

  1. Turn the keyswitch to the ON position.

  1. Wait at least 15 seconds for activation of the 04 diagnostic code.

    Note: Monitor the "Active Diagnostic Codes" screen on Cat ET before installing the jumper wire and after installing the jumper wire.

  1. Remove the jumper wire. Check for an 04 diagnostic code again.

  1. Turn the keyswitch to the OFF position.

Expected Result:

An 04 diagnostic code is active when the jumper wire is installed. An 03 diagnostic code is active when the jumper wire is removed.

Results:

  • OK - The engine harness and the ECM are OK.

    Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the transmission. 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 - The 03 diagnostic code remains active with the jumper in place. Proceed to Test Step 8.

Test Step 8. Check the Operation of the ECM

  1. Turn the keyswitch to the OFF position.

  1. Check the operation of the ECM by creating an open circuit at the ECM:

    1. Remove the signal wire for the sensor from the J2 connector.

    1. Remove terminal P2-17 (return).

    1. Turn the keyswitch to the ON position. Monitor the "Active Diagnostic Code" screen on Cat ET. Wait at least 15 seconds for activation of the code.

      An 03 diagnostic code should be active for the sensor.

  1. Check the operation of the ECM by creating a short at the ECM:

    1. Install a wire jumper between terminals P2-27 (signal) and P2-17 (return).

    1. Monitor the "Active Diagnostic Code" screen on Cat ET. Wait at least 15 seconds for activation of the code.

      An 04 diagnostic code should be active when the wire jumper is installed.

    1. Remove the wire jumper. Return all wiring to the original configuration.

Expected Result:

An 03 diagnostic code is active when the signal wire is removed from the ECM connector. An 04 diagnostic code is active when the signal wire is connected to the return wire.

Results:

  • OK - The ECM is working properly. The problem is in the wiring between the ECM and the harness connector. There may be a problem in a connector.

    Repair: Repair the wire and/or the connector. Replace parts, if necessary.Verify that the problem is resolved.

    STOP

  • Not OK - One of the following conditions exists: The 03 diagnostic code is not active when the sensor signal wire is disconnected. The 04 diagnostic code is not active when the wire jumper is installed.

    Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Verify that the original problem is resolved.

    STOP

Information System:

C7 Engines for Caterpillar Built Machines Finding Top Center Position for No. 1 Piston
C32 Marine Engines Switch Circuits - Test
C32 Marine Engines Injector Solenoid Circuit - Test
C32 Marine Engines Indicator Lamp Circuit - Test
C27 and C32 Industrial and Petroleum Engines Engine Temperature Sensor Open or Short Circuit - Test
307D, 311D, 312D, 313D, 315D, 318D, 319D, 320D, 323D, 324D, 325D, 326D, 328D, 329D, 330D, 336D, 340D, 345D, 349D, 374D, 390D and M325D Excavators Air Conditioning and Heating Heating System Troubleshooting
C7 Engines for Caterpillar Built Machines Engine Oil Pressure - Test
C7 Engines for Caterpillar Built Machines Turbocharger - Inspect
C7 Engines for Caterpillar Built Machines Fuel System Pressure - Test
C7 and C9 Marine Engines Engine Synchronize Switch Circuit - Test
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Wastegate - Test
C32 Marine Engines Engine Speed/Timing Sensor Circuit - Test
312C, 322C, 325C and 330C Excavators and TK1051 Track Feller Buncher Air Conditioning and Heating Machine Preparation for Troubleshooting
307D, 311D, 312D, 313D, 315D, 318D, 319D, 320D, 323D, 324D, 325D, 326D, 328D, 329D, 330D, 336D, 340D, 345D, 349D, 374D, 390D and M325D Excavators Air Conditioning and Heating General Troubleshooting Information
307D, 311D, 312D, 313D, 315D, 318D, 319D, 320D, 323D, 324D, 325D, 326D, 328D, 329D, 330D, 336D, 340D, 345D, 349D, 374D, 390D and M325D Excavators Air Conditioning and Heating Visual Inspection
307D, 311D, 312D, 313D, 315D, 318D, 319D, 320D, 323D, 324D, 325D, 326D, 328D, 329D, 330D, 336D, 340D, 345D, 349D, 374D, 390D and M325D Excavators Air Conditioning and Heating Air Conditioning E43 - Damper (Air Outlet)
311B, 312B, 315B, 320B, 322B, 325B and 330B Excavators Air Conditioning and Heating Refrigerant System - Evacuate
3412E Petroleum Engine Auxiliary Temperature Sensor Circuit - Test
311B, 312B, 315B, 320B, 322B, 325B and 330B Excavators Air Conditioning and Heating Refrigerant System - Charge
3500 and 3500B Engines Aftercooler Core - Inspect/Clean
C7 Engines for Caterpillar Built Machines Cooling System - Test
2005/01/17 New Bearings for the Engine Oil Pump are Available {1304}
C9.3 Tier 4 Final Engines Fuel Filter Base
3412E Petroleum Engine Intermittent Engine Shutdown