hey guys after doing some reserch i found out that either i have a bad wire or trans temp sensor becaues it reads -40 and my car wont downshift properly and the converter wont lock up.

i would like to test the wiring but not sure what wire on the trans goes where for the trans temp sensor. need to know what the voltage should be too

can anyone help

 

Shoebox has the 95 wiring diagrams and harness layout on his website:

The trans temp sensor is shown on sheet 7. Ground is a black wire that runs from pin B6 on the PCM, signal is a yellow/black wire that runs from pin D28 on the PCM. Look at the very bottom of the page.

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_wiring

The harness photo shows you what the A4 trans connector looks like:

http://shbox.com/1/harness.htm

This connector faces page shows the pinouts for the trans connector (although the diagram of the connector doesn't show up for me). 4L60 E connector is the last tab at the bottom of the page.:

http://shbox.com/1/harness_connector_faces.htm

The PCM pinouts and normal voltages are shown on these pages. Since its the typical thermistor type temp sensor, the PCM would supply 5.0V. The sensor will pull the voltage down, depending on the temperature. Low temp = high resistance = open circuit, as you have already stated.:

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_pinouts

 

wiring test out good, i changed the trans pressure switch which has the temp sensor in it. i get 5 volts from the pcm, reset pcm, and still reads -40

could i possibly have a bad pcm, and can it be repaired?

 

Did you check the resistance of the trans temp sensor, to insure it didn't have an open circuit? Measure the resistance across the pins on the tranny. Shoebox's wiring diagram has the correct resistance indicated.

Could the harness pins be damaged?

 

where exactly should i measure/ test this?

on the actual sensor or should i do it on the main trans connector that faces up, how would i reach those pins to test them?

 

I don't have a 4L60E, so I can't help you on how to reach things. If you have 5V at the harness connector, the next logical place to look is the resistance of the sensor, as measured from the harness connector on the tranny.

 

thank you for all your help, i tested for resistance on the sensor and it according to shoebox's page its reading room temp, so there has to be a problem within the wiring in the trans, got to somehow get to the pins on the trans connector.

borrowed a loaner pcm from another 95 car and it reads the same thing -40