No downshift no noise it runs fine?

2003 CHEVROLET S-10
154,000 MILES • 4.3L • 6 CYL • 4WD • AUTOMATIC
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CASTAWAY52
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The trans shift in all gears with no problem it smooth, no noise it runs fine, the problem when I give it gas to say trying to pass or going up a hill it won't downshift to gain speed. Besides that the engine runs well no erratic idle or stalling, it runs like it should. Suggestion? Thanks.
Jul 13, 2025 at 4:58 AM
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CASTAWAY52
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I went out and installed my scanner on it.
P101 MAF circuit range 1.
P102 MAF A circuit low.
P0758 Shift solenoid B electrical (present and pending).
Jul 13, 2025 at 8:30 AM
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STRAILER
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I have seen the TPS sensor cause this issue but most of the time there will be a code. Since you have a code for the Shift solenoid, but we should swap it out, here is the location of the solenoid, it has a red/blk and ltblu/wht wire going to it. This is a the pressure control solenoid so it will definitely control the downshift. You must replace the pressure manual valve position switch as well; I have marked them below. Check out the images (below). Let us know how it goes. please start a new thread for the MAF sensor issues.
Image (Click to enlarge)
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Jul 13, 2025 at 1:21 PM
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CASTAWAY52
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Was thinking the same also. If I have to get into it, I am going to order a GM kit with all the solenoid wiring harness etc. Get it done in one job. Thanks.
Jul 14, 2025 at 4:41 AM
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STRAILER
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Good call, that should fix it, please let me know.
Jul 14, 2025 at 7:51 AM