Code P0748

1997 CHEVROLET 1500
290,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
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AUGIE DELIA
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  • 9 POSTS
Looking for some help here the truck listed above is a k1500. I recently was replacing the pitman arm (along with the idler arm/bracket, outer/inner tie rods on both tires). When I was replacing the pitman, I may or may not have caused a small leak from the gearbox (it had 290,000 miles so I was fine replacing it). Now I have replaced the Gearbox too and I am getting error code P0748. I am concerned I did something wrong in the assembly and now its affecting the transmission. Can anyone provide any direction? My head is in the clouds.
Apr 7, 2021 at 10:32 AM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

The code is related to the pressure control solenoid. This is what maintains the fluid pressure in the transmission. If the transmission was used, the solenoid may be bad. Did you have the transmission pan removed? The PCS is located on the valve body. If you look at pic 1 below, I highlighted it.

Are you experiencing a hard or soft shift?

The remaining attachments are the diagnostics related to this code. Take a look through them and let me know if you are comfortable performing them.

Take care,

Joe

See pics below
Images (Click to enlarge)
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Apr 8, 2021 at 7:49 PM
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AUGIE DELIA
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This seems a little bit out of my comfort zone. I looked up a video replacing the sensor by removing the pan, letting the oil drip out and the easily swapping the sensor and replacing the pan. But this seems a lot more involved than that.

Is this the type of job that should be done by a professional?
Apr 9, 2021 at 5:21 AM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

If you take your time and follow the directions, it really isn't too hard. Did you already have the pan off?

As far as a professional, it isn't the easiest job, but if you are mechanically inclined and take your time, you should be okay.

Let me know if I can help.

Take care,

Joe
Apr 9, 2021 at 7:11 PM