ELBOW-TURBO TO MUFFLER 4P1660 - Caterpillar

[ OPTIONAL USE ]
The "Resistive Temperature Device" (RTD module is not required.General Information
The resistance of a given material changes as the temperature of the material changes. TheRTD uses the principle in order to measure temperature. An RTD is a passive device that requires an external excitation current. Once the current is supplied to the RTD, the voltage is read across the RTD terminals. The voltage is converted into a temperature using a simple mathematical algorithm.Although resistive temperature devices are more costly than thermocouples, resistive temperature devices are widely used because of the excellent stability. Resistive temperature devices exhibit the most linear signal with respect to temperature of any electronic temperature sensor. The typical metallic elements used in an RTD are nickel, copper, and platinum. Platinum is one of the more commonly used metals in RTD because of the wide temperature range, accuracy, and stability of the metal.Module Overview
The RTD module is a temperature scanner that can read eight platinum RTD inputs. The eight platinum RTD inputs can have two, three, or four wire configurations. The four wire input is the most accurate. The four wire input uses one pair of wires for the excitation current and a separate pair of wires to measure the voltage.The RTD module will read the inputs, apply the algorithm, and then calculate the temperature in degrees Celsius. The RTD module will then broadcast the information onto the J1939 data link. The EMCP 3 will read the information from the RTD module and display the information on the display screen.The RTD module is also capable of generating diagnostics. The diagnostics that are generated by the RTD module are maintained in non-volatile memory. The diagnostics are stored in order to ensure that the diagnostics are available following a power loss.Diagnostics
The RTD module can store 20 event log entries that can be viewed from the ECM. The entries are broadcast on the J1939 data link.Each of the eight inputs have sensor diagnostics in order to detect open or short circuits that go to the RTD sensors. Over temperature warnings and shutdowns, as well as under temperature warnings, are detected by comparing the measured temperature to the low warning, the high warning, and the high shutdown temperatures that are stored in the module. The EMCP 3 reads the messages and annunciates and/or performs engine shutdown appropriately. Any of the inputs can be disabled in order to prevent unnecessary diagnostic faults.Table 1 shows the format for the log entries.
Table 1
Diagnostic Log Entry Format Table    
Suspect Parameter Number (SPN) (1)    
Failure Mode Indicator (FMI ) (2)    
Time of Last Occurrence    
Date of Last Occurrence    
Time of First Occurrence    
Date of First Occurrence    
Engine Run Hours First Occurrence    
Engine Run Hours Last Occurrence    
Number of Occurrences    
Security to Clear Log Entry    
( 1 ) See Table 3 for possible code numbers.
( 2 ) See Table 2 for possible code numbers.Table 2 shows the RTD module diagnostics.
Table 2
RTD Module Diagnostics