2 Codes, P0748 and P0751
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LOTS of threads on them, but none seem to have these together, so just incase I'm missing a bigger picture I figured I'd make a post.
P0748 - Pressure Control Solenoid Electrical
Will be checking the connections and replace if necessary. However, one of the triggers for the code is the RPM's not matching the right gear or something to that effect. Code came on after I put the shifter in 3 floored it from 40 to show a friend its speed and how easily it merges with highway traffic![Angel](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_angel.gif)
When I bought the car I was told that it would set the SES sometimes because the car doesn't know it has 3.23's in it. Couldn't really find threads on that but it fits the RPM mistmatch description, car used to have 3.73's but I don't know what the car came with or what it thinks it has.
Seems to shift fine, a hard shift while driving slow and in that residential and stop and go range only now and then, I think its more of a low speed clunkyness I've known all GM 4 speeds to have in that 1-2-1 zone. Wide open throttle and casual driving shifts are flawless.
P0751 - 1-2 Shift Solenoid Performance
Car has a 4000 stall so I assume that is the cause of this one since I have all gears even when the SES is on.
I'm thinking I just need a little tune work done, hopefully a couple guys I know can just make these few adjustments for me.
P0748 - Pressure Control Solenoid Electrical
Will be checking the connections and replace if necessary. However, one of the triggers for the code is the RPM's not matching the right gear or something to that effect. Code came on after I put the shifter in 3 floored it from 40 to show a friend its speed and how easily it merges with highway traffic
![Angel](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_angel.gif)
When I bought the car I was told that it would set the SES sometimes because the car doesn't know it has 3.23's in it. Couldn't really find threads on that but it fits the RPM mistmatch description, car used to have 3.73's but I don't know what the car came with or what it thinks it has.
Seems to shift fine, a hard shift while driving slow and in that residential and stop and go range only now and then, I think its more of a low speed clunkyness I've known all GM 4 speeds to have in that 1-2-1 zone. Wide open throttle and casual driving shifts are flawless.
P0751 - 1-2 Shift Solenoid Performance
Car has a 4000 stall so I assume that is the cause of this one since I have all gears even when the SES is on.
I'm thinking I just need a little tune work done, hopefully a couple guys I know can just make these few adjustments for me.
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these codes usually come about when a 3,400+ stall is installed on our cars. The computer thinks the stock stall is in the car and knows how much it should slip under normal driving. Now install a 4k stall and it slips way past the normal range and sets off the codes. Do you notice if the car looses gears and it seems like your starting off in 3rd gear. Usually if you pull off to the side of the road, turn the car off, wait a min, then restart the car it will drive like normal till the rpm missmatch happens then sets the codes off again. Its a simple fix by just turning the codes off. Happens to alot of guys.
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I would agree that PO751 is likely related to the stall and or the gear ratio mismatch or a little of both, However the P0748 PCS ELECTRICAL is likely a real fault that accompanied with the harsh low throttle shifts would suggest either the solenoid itself is open or a wire leading to it.
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After my fluid and filter change, making sure all the connections were good and nothing pinched, and the computer being programed for the right gears, I haven't had the light come back on. *fingers crossed*