SHAFT ASSEM. 1T0764 - Caterpillar

Illustration 1 g03366391
Schematic of the PWM sensors for the sensor signal circuit
Illustration 2 g03281016
Terminal locations at the P2 ECM connector (prim.) for the sensors for the turbocharger turbine inlet temperature (P2-29) Digital supply (prim.) (P2-65) Left turbocharger turbine inlet temperature (prim.) (P2-73) Right turbocharger turbine inlet temperature (prim.) (P2-92) Digital return (prim.)
Illustration 3 g01240891
Sensor connector (Terminal 1) Sensor supply (Terminal 2) Sensor return (Terminal 3) Signal
Table 2
Troubleshooting Test Steps    Values    Results    
1. Check for an "Active" Diagnostic Codes
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector.
B. 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.
C. Determine if a diagnostic code has occurred several times.
Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a bad connection between a socket and a pin in a connector. There could also be a bad connection between a wire and a terminal.
D. Look for one or more of the following diagnostic codes that are active or logged:
- 2433-3
- 2433-4
- 2433-8
- 2434-3
- 2434-4
- 2434-8
   
Codes    
Results: No diagnostic codes are active.
Repair: There may be an intermittent problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct procedures for inspecting electrical connectors.
Results: One of the diagnostic codes that are listed above are active or logged.
The ECM detects a problem in one of the circuits for the exhaust temperature sensors.
Proceed to Test Step 2
   
2. Check the Digital Supply Voltage at the Sensor Connector
A. Turn the main disconnect switch to the OFF position.
B. Disconnect the suspect sensor at the sensor connector:
C. Restore the electrical power to the ECM.
D. Measure the supply voltage on the harness side of the sensor connector. Measure the voltage between terminal 1 and terminal 2 for the suspect sensor.
   
8.0 0.4 VDC    
Results: The supply voltage is 8.0 0.4 VDC. The supply voltage is reaching the sensor connector.
Proceed to Test Step 4
Results: The supply voltage is not 8.0 0.4 VDC. The supply voltage is not reaching the sensor connector.
Proceed to Test Step 3
   
3. Check the Digital Supply Voltage at the ECM
A. Turn the main disconnect switch to the OFF position.
B. Disconnect the J2/P2 and the J1/P1 ECM connectors.
C. Fabricate three jumper wires that are long enough to use as test leads at the ECM connector. Crimp connector sockets to one end of each of the jumper wires.
D. Remove the wires for the digital supply from terminal locations P2-29, P1-5 and P1-18. Install a jumper wire into each of these terminal locations.
E. Connect the J2/P2 ECM connectors.
F. Restore the electrical power to the ECM.
G. Measure the voltage between the jumper wires that are in terminals P2-29 and P1-5.
Measure the voltage between the jumper wires that are in terminals P2-29 and P1-18.
H. Turn the main disconnect switch to the OFF