Mechanics

SATURN SL1 TRANSMISSION PROBLEM

1997 Saturn SL1 • 150 miles

Codepo731 car drives fine had transmission pressure checked and it was good I clear the code and once a week it come back the car drives fine don't know what the is wrong with it is any suggestions thanks
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Bubba1969
February 17, 2013.



There is a service bulletin regarding a PO731. Are you getting a slipping from 1st gear or a rough shift?

SES) Service Engine Soon Light On with Diagnostic Trouble Code (DTC) P0731, No Movement in Drive During Cold Ambient Temperatures (Replace Oil Pump or 1st Gear Sprag Clutch Assembly) #03-07-30-008A - (May 12, 2004)

(SES) Service Engine Soon Light On with Diagnostic Trouble Code (DTC) P0731, No Movement in Drive During Cold Ambient Temperatures (Replace Oil Pump or 1st Gear Sprag Clutch Assembly)

1998-2002 Saturn S-Series Vehicles

with Automatic Transmissions (MP6/MP7)

Check to see when your vehicle was built, This could relate to your vehicle.

The Saturn was made in 1997 and we don't have any shift problems in cold weather the strange part of it is when I take the car over and power wash the car and play with the norm or prof switch on the side of the shifter the service light goes out on it's own and I don't have to turn the light out the code is still in the memory this car is a pain in my butt let me know what you think

Tiny
Bubba1969
Feb 18, 2013.
Just to add to this one did you just have a high low pressure test performed?If so what was the pressure at idle in park with the line pressure fuse in and with it out?Also a step pressure test should be done that will tell you if you have a worn pressure regulator bore in the valve body very common on that car. Also the pressures should be checked with the line pressure fuse in and the car in revesre and in drive. Also the pressure should be watched when placing the car in reverse if the pressure is slow to build to full line pressure you could have a loose input shaft nut very common on those cars. Do you have a delay bang or delay into reverse?Has anyone done a actuator audiable test when the code is active?

Saturntech9
Feb 18, 2013.
Transmission guy check the pressure in park with fuse in and out and said that all pressures where great they where what they should be I don't know the numbers no delay bang or delay in reverse the guy put his computer on it and run the car in all gears while the code was active in the cars computer

Tiny
Bubba1969
Feb 18, 2013.
Also the only code he got was the po731 but no reason why I was wondering if it was the speed sensor or first gear soleniod

Tiny
Bubba1969
Feb 18, 2013.
I would still do a step pressure test to test for worn pressure regulator bore you need a tech to do that with a pressure gauge.

Saturntech9
Feb 18, 2013.
The transmission guy was a tech and he hook the car up to pressure gauge through the heat sensor and found no problem with transmission pressure that's why it is so strange because the transmission works good when it is hot or cold no delays he told me that all pressures where correct he spent 2 hours checking it

Tiny
Bubba1969
Feb 18, 2013.
I was also told that sometimes the speedometer could set off code po731 I checked it and notice that it makes a noise when you drive the car this speedometer doesn't have a cable to it

Tiny
Bubba1969
Feb 18, 2013.
, If he only checked the pressure with the line pressure fuse in and with it out and didnt do a step pressure test he didnt do a step pressure he didn't do a full line pressure test.A step pressure test you use a tech 2 scan tool and has the computer command the pressures to all different pressures starting with the lowest pressure to the highest pressure and you watch a see if each step is within range of what its commanded?Its a great way to check for a worn pressure regulator bore. It doesn't sound like you have a bad 1st gear clutch pisiton. It sounds like you have wire issue pressure control solenoid issue or a worn pressure regulator bore in the valve body.I know how to test the pressure on these transmissions I am factory trained Saturn tech I went to spring hill Tennessee where they build them for training.I have also worked for Saturn dealers for over 16yrs working on them so I know these cars well.

Saturntech9
Feb 18, 2013.
I'm going down to talk to the tech this afternoon and I'll tell him what you said and let him test the computer while the code is still in there and see what happens I'll let you know thanks

Tiny
Bubba1969
Feb 18, 2013.
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