0331696 JOHNSON GASKET, Cover

Table 1
Diagnostic Codes Table    
Code and Code Description    Conditions which Generate this Code    System Response    
827-3
Left Exhaust Temperature Sensor : Voltage Above Normal     The ECM detects a duty cycle that is greater than 96 percent for 10 seconds.     The code is logged.
If the signal from the other exhaust temperature sensor is OK, the signal from that sensor is used. If the signal from the other exhaust temperature sensor is not OK, a default value is used.    
827-4
Left Exhaust Temperature Sensor : Voltage Below Normal     The ECM detects a duty cycle that is less than 4 percent for 10 seconds.    
827-8
Left Exhaust Temperature Sensor : Abnormal Frequency, Pulse Width, or Period     The ECM detects a sensor frequency that is greater than 600 Hz or less than 400 Hz.    
828-3
Right Exhaust Temperature Sensor : Voltage Above Normal     The ECM detects a duty cycle that is greater than 96 percent for 10 seconds.     The code is logged.
If the signal from the other exhaust temperature sensor is OK, the signal from that sensor is used. If the signal from the other exhaust temperature sensor is not OK, a default value is used.    
828-4
Right Exhaust Temperature Sensor : Voltage Below Normal     The ECM detects a duty cycle that is less than 4 percent for 10 seconds.    
828-8
Right Exhaust Temperature Sensor : Abnormal Frequency, Pulse Width, or Period     The ECM detects a sensor frequency that is greater than 600 Hz or less than 400 Hz.    
2433-3
Engine Exhaust Gas Temperature - Right Manifold : Voltage Above Normal     The ECM detects a duty cycle that is greater than 96 percent for 10 seconds.     The code is logged.
If the signal from the other exhaust temperature sensor is OK, the signal from that sensor is used. If the signal from the other exhaust temperature sensor is not OK, a default value is used.    
2433-4
Engine Exhaust Gas Temperature - Right Manifold : Voltage Below Normal     The ECM detects a duty cycle that is less than 4 percent for 10 seconds.    
2433-8
Engine Exhaust Gas Temperature - Right Manifold : Abnormal Frequency, Pulse Width, or Period     The ECM detects a sensor frequency that is greater than 600 Hz or less than 400 Hz.    
2434-3
Engine Exhaust Gas Temperature - Left Manifold :Voltage Above Normal     The ECM detects a duty cycle that is greater than 96 percent for 10 seconds.     The code is logged.
If the signal from the other exhaust temperature sensor is OK, the signal from that sensor is used. If the signal from the other exhaust temperature sensor is not OK, a default value is used.    
2434-4
Engine Exhaust Gas Temperature - Left Manifold : Voltage Below Normal     The ECM detects a duty cycle that is less than 4 percent for 10 seconds.    
2434-8
Engine Exhaust Gas Temperature - Left Manifold : Abnormal Frequency, Pulse Width, or Period     The ECM detects a sensor frequency that is greater than 600 Hz or less than 400 Hz.    System OperationUse this procedure to troubleshoot any suspect problems with the sensor for the left turbocharger turbine inlet temperature or the right turbocharger turbine inlet temperature.The Pulse Width Modulated Sensor (PWM) provides a signal to the ECM. The PWM signal is used to represent certain engine operating conditions. The sensors receive 8.0 0.4 VDC from a regulated power supply.The ECM performs an automatic calibration of these sensors whenever the ECM is powered and the engine has been off for at least 5 seconds.The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.The following components can cause problems with the power supply:
Electrical connector or wiring
Sensor
ECMThe most likely cause of a problem is a problem with an electrical connector or wiring. The least likely cause is a problem with the ECM.
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