Electronic Transmission and Scan Tools

Abbreviations

PCM - Powertrain Control Module
TCC - Torque Converter Clutch
TPS - Throttle Position Sensor
ECT - Engine Coolant Temperature Sensor
VSS - Vehicle Speed Sensor
RSA - Transmission Range Fluid Pressure Switch Assembly
TTS - Transmission Temperature Sensor


Sketch a wiring diagram.




Which solenoids are "on when this vehicle is shifted into Drive and starts out in 1st gear?
1-2 and 2-3

Which solenoids are "on" when this vehicle automatically shifts into 2nd gear?
2-3

Which solenoids are "on" when this vehicle automatically shifts into 3rd gear?
None.

Which solenoids are "on" when this vehicle automaticallyshifts into 4th gear?
1-2


Shift solenoid malfunction: Describe what would happen if none of the solenoids came "on". Would the vehicle drive?
Yes it would be able to drive in fail safe mode; since 3rd gear doesnt need solenoid actuation to operate.
What gear would it be in?
It would be in 3rd gear.
How fast could the vehicle go?
It would start off very slow since it would be starting off straight in 3rd gear, and torque would be low; but would eventually reach speeds approximately 50km/h without riding it.
Could it have the power to climb a hill?
It might not, however if you get it going 50km/h constantly you probably could for a little while.

Codes: Pick 2 transmission codes out of repair information, and describe what the code means and what malfunction would cause the code.

1. Code 15
Engine coolant temprature sensor - Circuit voltage high when engine has been running more than 60 seconds and ECT has greater then 4.74 volts at less then 33 degrees.
Maybe a faulty temperature sensor, ECT has poor ground or connection, Coolant may need to be changed, radiator possibly broken, or maybe head gasket needs to be replaced.

2. Code 21
Throttle Position Sensor -Signal voltage stays 4.9v for about two seconds at engine idling.
Maybe a poor earth, faulty sensor, possibly the throttle/butterfly needs attention and cleaning.

Diagnosis.
For each code listed above, discuss what tests you could run to diagnose the problem

1. For the ECT sensor, Volt drop or resistance check it to see if its within proper manufacturer's specifications.

2. For the TPS, in code 21 it states that voltage stays at 4.9v for about 2 seconds at idle. This basically means that its at wide open throttle for 2 seconds while its idle.
You could connect an oscilloscope or multimeter to the TPS and volt drop or observe it. Or if its easily accessible, you could just pop the bonnet and monitor the throttle butterfly.