Codes after a/c replacement

[chevyrider838]

99 K1500. Replaced compressor, a/c hoses, accumulator, condenser, upgraded to 140 alternator, belt drive tensioner, and serpentine belt. Speedometer and rpm gauge aren’t working. Also experiencing slow acceleration from stop as if the truck is in a higher gear and getting codes PO0740, P1860, PO758 and PO753 all seemingly related to transmission solenoid and shift. Could I have unplugged something that I shouldn’t have? Any suggestions? Looking for the fix. Thanks guys.

 

[GoToGuy]

First, go back review everything you did, anything you touched, leaned on , unplugged, disconnected, reconnected. Something not connected. It sounds like a " self induced problem".

 

[xXxPARAGONxXx]

Check your grounds. I believe there is one underneath the accumulator on a stud on the firewall. I believe there's another on the intake manifold on a stud on the thermostat housing. (The engine wiring harness on this truck was spliced into, so I have to make an assumption on the latter ground location.)

 

[east302]

For a 1998 P0740, first steps say to check for a blown TRANS fuse since you have those other codes…

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[Jeepwalker]

Don't overlook the ground. Current (electrons) flows from Neg to Pos, so a bad ground can screw up a lot on electronics. But yeah, could be something with your tranny fuse or a wire. Check underneath that a rodent didn't chew some wires.

Also, might not hurt to reset your truck's computer modules: unhook your battery cables (from the battery) and tie the cable ends together for an hour or two.

 

[99tahoemomma]

@chevyrider838

Did you find a solution to your problem? After going a couple places this am, I cranked my Tahoe and now have the same codes and description while driving home as yours did. P0740, P0753, P0758, P1860. Only have around 5000 on my engine and transmission (replaced/rebuilt a couple months ago). Thanks!