SQ Hans

This week I learned about using different scan tool software to check active codes on different engine. I was then able to use this same software to my advantage to troubleshoot t problems.

 

 using the modis to activate the horn and windshield wipers on the black dodge

 

 I was able to use the laptop to find the active code on the Cummins ISX and then I was also able to check the voltage to the VGT actuator.

 

I found the active code on the powerstroke using IDS. I was also able to use the IDS to monitor then fuel rail pressure and the voltage to the sensor that was causing the engine to throw a code. 

SQ Hans

 This week I finished the tear down and reassembly of my cylinder on the 3516 cat. This engine requires the you be very precise. Just how you hold the tools you are using can make the difference of out of spec or in spec, since some of the measurements require you to be accurate down to .0001". This kind of work requires a lot of attention to detail and cleanliness. I did a good amount of measurements on this engine, including measuring valves, lifter bores, rocker arms, liner, piston, connecting rod, wrist pin, and more, but looking through the service manual for this engine there is just about a measurement for anything and everything on this engine.

 

This week = 55, total = 564 

SQ Hans

This week I learned about how a thermistor functions. It functions in the same way as a potentiometers and is used in various applications where temperatures are monitored. A potentiometer functions using a resistor and a contact moves along the resistor as a path for voltage to flow and as the contact moves it  makes the voltage flow through more or less of the resistor. When less of the resistor is used the voltage is higher and when more of it is used then the resistance is lower, A thermistor functions when temperature rises and lowers. A reference voltage is sent to the ECM and the thermistor, the reference voltage is goes through a resistor to drop the voltage to 5 volts. When the temperature in the thermistor starts to rise less of the resistor in the thermistor is used and the resistance in the circuit decrease. Since the resistance in the thermistor decreases the voltage drop of the reference voltage increases. Using the formula voltage =amps x ohms shows that if the current flow is the same and the resistance is lowered then the voltage will be less.

 

 

Potentiometer

 

Water temp sensor using a thermistor 

 

This week = 62 

Temperature sensor circuit