Mechanics

TRANSMISSION TROUBLES

1994 Saturn SC2 • 170,000 miles

94 Saturn SC2 Duel Overhead Cam 1.9L
I recently changed out my radiator and afterwards the transmission started acting weird. It would slam into reverse and buck when going backwards. It would start out in 2nd or 3rd and barely go forward. After gaining speed it would run fine but sometimes kick in and out of gear. Sometimes it would run great with no signs of problems. I just never know how it's going to act from day to day. Tried to pull codes but the check engine light bulb is out and the mech told me that in older cars if the bulb is burned out the code reader will not interact with the PCM. PLEASE HELP!
"JMAN69"
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Jaselatil
June 12, 2012.



If the check engine light is burned out it will set a code 26 quad circuit failure. The scan tool will still work I have used the scan tool to retrive codes with the check engine bulb removed or burned out. He is blowing smoke saying that he probably doesnt have a scan tool to read the codes. Actron makes a tool that plugs into your diagnostic link connector with a switch for abs transmission and engine codes.I have never used one since I have always had the saturn scan tool. But I think the tool itself flashes the codes out. Check it out so we can see what codes you have. But changing the radiator will have nothing to do with the transmission shifting. Unless you let a lot of fluid leak out when changing it. Make sure the fluid level is full it sounds like a pressure issue very common on those cars by a worn or sticking pressure regulator bore in the transmission valve body.

Saturntech9
Jun 12, 2012.
I'll double check on the scan tool.
I changed the transmission filter and fluid at the time I changed out the Radiator. Do you think this may have something to do with it?
"JMAN69"

Tiny
Jaselatil
Jun 12, 2012.
Bingo check right next to the transmission filter laying across the transmission filter there is the harness for the input speed and the transmission temp sensor. See if you damaged one of those harnesses most likely the harness going to the input speed sensor. That will cause the issues your having. Remove the box so you can get a good look at it. Let me know what you find.

Saturntech9
Jun 12, 2012.
I changed the sensor a while back after a mech shop knocked off the wires when changing my trans filter. I had to kinda rig it up but it worked. I changed out the plug harness when I changed out the radiator. Do you think the input speed sensor may have gone bad? While checking it today I knocked one of the wires loose and had to drive it home to reconnect. It did not change the way it acted. No change what so ever.
JMAN69

Tiny
Jaselatil
Jun 13, 2012.
That sensor is the same one as the output speed sensor they rarely fail I have only really replaced them because they were leaking fluid into the connector. If your sure the connector is in good shape and the butt connectors are crimped good?Well I guess we have to see what codes you have?Have you checked into the actron code flasher yet to see if the tool flashes rather then the check engine light?

Saturntech9
Jun 13, 2012.
I just looked at the tool and it uses the check engine light to flash the codes out. We need to replace the check engine bulb and we can flash the codes out with a paper clip.

Saturntech9
Jun 13, 2012.