3176C Engine for the R1600G and the R1700G Load Haul Dumps Sensor Supply - Test Caterpillar


Sensor Supply - Test
`

System Operation Description:

Use this procedure to troubleshoot the electrical system if a problem is suspected with a sensor supply or if either of the diagnostic codes in Table 1 is active or easily repeated.

Table 1
Diagnostic Codes Table    
Code and Description     Conditions which Generate this Code     System Response    
262-3 5 Volt Sensor DC Power Supply voltage above normal     The analog sensor supply voltage is above normal for two seconds.
The Electronic Control Module (ECM) has been powered for three seconds.    
The code is logged.
All sensors are set to default values.    
262-4 5 Volt Sensor DC Power Supply voltage below normal     The analog sensor supply voltage is below normal for two seconds.
The ECM has been powered for three seconds.    

System Operation

The ECM supplies a regulated voltage of 5.0 ± 0.2 VDC to the following sensors:

  • Atmospheric pressure sensor

  • Coolant temperature sensor

  • Engine oil pressure sensor

  • Fuel temperature sensor

  • Intake manifold air temperature sensor

  • Right turbocharger inlet pressure sensor

  • Turbocharger outlet pressure sensor

The supply voltage for the sensors is routed from the ECM to terminal A of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal B of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.

Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If the -3 diagnostic code is active, it is possible that a sensor has been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has failed.




Illustration 1g01409385

Typical schematic

Test Step 1. Inspect Electrical Connectors and Wiring

  1. Turn the keyswitch to the OFF position.

  1. Remove electrical power from the ECM.



    Illustration 2g01139425

    ECM

    (1) J1/P1 connectors

    (2) J2/P2 connectors

  1. Thoroughly inspect the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit.

    Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.




    Illustration 3g01409630

    P2 ECM connector

    (P2-30) Sensor return

    (P2-36) Sensor supply




    Illustration 4g01159881

    Sensor connector

    (A) +5 V sensor supply

    (B) Sensor return

    (C) Signal

  1. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.

  1. Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

  1. Check the harness and wiring for abrasion and for pinch points from the sensors back to 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 - The harness and 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 connectors or wiring and/or replace the connectors or wiring. 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 AVSpare Electronic Technician (ET) to the service tool connector.

  1. Restore electrical power to the ECM.

  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. Look for the following diagnostic codes:

    • 262-3

    • 262-4

    Note: Wait at least 30 seconds in order for the diagnostic codes to become active.

Expected Result:

No diagnostic codes are active.

Results:

  • OK - No diagnostic code is active.

    Repair: The problem is no longer present. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".

    STOP

  • Not OK - A 262-3 or 262-4 diagnostic code is active at this time. Proceed to Test Step 3.

Test Step 3. Disconnect the 5 Volt Sensor(s) while you Monitor the Active Diagnostic Codes

  1. Monitor the active diagnostic code screen on Cat ET while you disconnect each 5 Volt sensor at the sensor connector. Check for an active 262-3 code or an active 262-4 code.

    Note: Wait at least 30 seconds in order for the diagnostic codes to become active.

  1. Disconnect the following sensors one at a time:

    • Atmospheric pressure sensor

    • Coolant temperature sensor

    • Engine oil pressure sensor

    • Fuel temperature sensor

    • Intake manifold air temperature sensor

    • Right turbocharger inlet pressure sensor

    • Turbocharger outlet pressure sensor

Expected Result:

The diagnostic code deactivates when a particular sensor is disconnected.

Results:

  • OK - The diagnostic code deactivates when a particular sensor is disconnected.

    Repair: Connect the suspect sensor. If the code returns, replace the sensor with a new sensor. Connect the connector(s). Verify that the problem is resolved.

    STOP

  • Not OK - The diagnostic code remains active after a sensor is disconnected. Leave the sensor disconnected. The sensor is not the cause of the diagnostic code. Proceed to Test Step 4.

Test Step 4. Check the +5 V Supply Voltages at the ECM

  1. Turn the keyswitch to the OFF position.

  1. Disconnect the J2/P2 ECM connector.

  1. Fabricate jumper wires that are long enough to be used to measure the supply voltages at the ECM connector. Crimp connector sockets to one end of each jumper wire.

  1. Remove the wires from terminal locations P2-36 (+5 V sensor supply) and P2-30 (sensor return). Install a jumper wire into each of these terminal locations.

  1. Reconnect the J2/P2 ECM connector.

  1. Turn the keyswitch to the ON position.

  1. Measure the voltage between the jumper wire in P2-36 (+5 V sensor supply) and the jumper wire in P2-30 (sensor return).

  1. Turn the keyswitch to the OFF position.

Expected Result:

The voltage measurement is 5.0 ± 0.2 VDC.

Results:

  • OK - The voltage measurement is 5.0 ± 0.2 VDC. The ECM is operating correctly.

    Repair: There is a problem with the harness. Repair the harness or replace the harness.

    STOP

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

    Repair: Replace the ECM. Refer to Troubleshooting, "ECM - Replace".

    STOP

Information System:

140M and 150 Motor Graders Engine Supplement Fuel Filter (Secondary) and Fuel Filter Base - Remove and Install
16M Motor Grader Operator Controls
C4.4 (Mech) Industrial Engine Fuel System Pressure - Test
3176C Engine for the R1600G and the R1700G Load Haul Dumps Sensor Signal (Analog, Active) - Test
Wiring the 9X-9591 Electrical Converter Gp (PULSE WIDTH MODULATED){1421, 1901, 7490}
770 and 772 Off-Highway Trucks Power Train Transmission Hydraulic Control - Assemble
770 and 772 Off-Highway Trucks Power Train Transmission Hydraulic Control - Disassemble
770 and 772 Off-Highway Trucks Power Train Transmission Hydraulic Control - Install
3176C Engine for Caterpillar Built Machines Injector Solenoid - Test
770 and 772 Off-Highway Trucks Power Train Transmission Hydraulic Control - Remove
2007/09/17 Additional Parts are Available for the Filler Cap {3177, 4332, 5056}
CS54 and CP54 Vibratory Soil Compactors Engine Air Filter Primary Element - Clean/Replace
Installing the 290-9911 Engine Enclosure Seal Kit {7263, 7263, 7273}
259B3 Compact Track Loader, 247B3 and 257B3 Multi Terrain Loaders and 216B3, 226B3, 236B3, 242B3 and 252B3 Skid Steer Loaders Power Train Piston Motor (Hydrostatic) - Assemble
CP76 and CS76 Vibratory Compactors Propel System Relief Valve (Main, Axle Propel Pump) - Test and Adjust
938H Wheel Loader and IT38H Integrated Toolcarrier Hydraulic System Relief Valve (Signal) - Test and Adjust
14M Motor Grader Safety Messages
797 Rear Wheel Bearing Full Single Life Reusability Guidelines {4201}
3176C Engine for the R1600G and the R1700G Load Haul Dumps Timing - Calibrate
Bench Test Procedure For A 784B, 784C, 785B, 785C, and 785D Off-Highway Truck Torque Converter{3101}
140M and 150 Motor Graders Engine Supplement Fuel Priming Pump and Water Separator - Remove and Install
924H, 924HZ, 928HZ and 930H Wheel Loaders MID 081 - CID 1960 - FMI 09
Reuse and Salvage for Turbochargers {0760, 0767, 1052}
R1600G Load Haul Dump Engine and Machine Warm-Up