Transmission shift selonoid (PO758)reading. Probable causes/solutions

There is a bulletin for this code that need to be checked first. After and if all check out here you can find the location of the solenoid. but with that code depending on if your transmissons is 4L60 e or4L80e its going to be a 3-2 shift sol. circuit. or 2-3 sol. and it's pretty eash to do, just drop the pan and you are there. good luck.
1. Remove the oil pan, gasket, and filter.



2. Disconnect the electrical connectors from the control valve body components. The electrical connectors locations are referenced by callouts (1) through (6).



3. Remove the bolts securing the pressuTransmission shift selonoid (PO758)reading. - 45104e4.gifo the control valve body.



4. Remove the torque converter clutch solenoid bolts.




5. Remove the retainer Transmission shift selonoid (PO758)reading. - a3c9090.gifd torque converter clutch solenoid (1). Remove the wiring harness bolts and let the wiring harness hang.


Remove the manual shift detent spring assembly. Remove the remaining control valve body bolts.


Remove the solenoid retainer (4) and the 1-2 shift solenoid (1).


Remove the solenoid retainer (4) and the 2-3 shift solenoid Transmission shift selonoid (PO758)reading. - dcf34dc.gifRemove the 2-3 shuttle valve (2) and the 2-3 shift valve (3).



Remove the coiled spring pin (1). Remove the 1-2 accumulator valve sleeve (2). Remove the 1-2 accumulator valve (3) and the 1-2 accumulator valve spring (4).

Remove the solenoid retainer bolt (7) and the solenoid retainer (6). Remove the pressure control solenoid (1). Compress the actuator feed limit valve spring (3). Remove the bore plug (5). Remove the actuator feed limit valve spring (3) and the actuator feed limit valve (4).



Remove the solenoid retainer (4) and the 3-2 controTransmission shift selonoid (PO758)reading. - 72bd8b0.gif(1). Remove the 3-2 control valve (2) and the 3-2 control valve spring (3).



Remove the bore plug retainer (1) and the bore plug (8). Remove the 3-2 downshift valve spring (2) and the 3-2 downshift valve (3). Remove the reverse abuse valve spring (5) and the reverse abuse valve (6).


Remove the bore plug retainer (1) and the bore plug (8). Remove the 3-2 downshift valve spring (2) and the 3-2 downshift valve (3). Remove the coiled spring pin (4) and the bore plug (7). Remove the reverse abuse valve spring (5) and the reverse abuse valve (6).



Remove the bore plug retainer (1) and the bore plug (5). Remove the 3-4 relay valve (2) and the 4-3 sequence valve (3) and the 4-3 sequence valve spring (4).


Remove the bore plug retainer (1) and the bore plug (5). Remove the regulator apply valve (4) and the regulator apply spring (3) and the isolator valve (2).

Condition:
Some customers may comment on one or more of the following conditions:
* The Malfunction Indicator Lamp (MIL) is ON
* The transmission is defaulted to second gear (4L80/85-E)
* The transmission is defaulted to third gear (4L60/65-E)
* The instrument cluster is inoperative

Upon investigation, one or all of the diagnostic trouble codes (DTCs) P0740, P0753, P0758, P0785, P0787, P0973, P0976, P1860, P2761, P2764 and P2769 may be set depending on the vehicle.

Cause:
The most likely cause of this condition may be a loss of voltage to the transmission solenoid power supply circuit.

This condition may also be the result of an incorrect installation of an aftermarket electronic device such as a remote starter or alarm system.

Correction:
Important: If the vehicle is equipped with an aftermarket electronic device and the DTCs are being set when the device is being used, verify that the appropriate fuse is being supplied battery voltage during operation. If voltage is not present at this fuse, these DTCs will be set due to lack of voltage at the solenoids. This condition is most likely to occur with an incorrectly installed remote starting system. If this is the case, refer the customer to the installer of the system for corrections. ANY REPAIRS DUE TO AFTERMARKET INSTALLATION OF ACCESSORIES IS A NON-WARRANTABLE ITEM.

With the ignition switch in the RUN position, test for battery voltage at the circuit fuse in the transmission solenoid power supply circuit. Refer to the appropriate SI Document for the transmission solenoid power supply circuit information.

If battery voltage is present at the fuse, inspect the ignition voltage circuit between the fuse and the transmission for possible opens.

If battery voltage is not present at the fuse, test for continuity between the fuse and the ignition switch. If NO continuity is between the fuse and the ignition switch, repair the open in that circuit.

If you have continuity between the fuse and the ignition switch, the most likely cause is the ignition switch. Replace the ignition switch using the appropriate Ignition Switch Replacement procedure in SI. Refer to group number 2.188 of the parts catalog for part description and usage of the ignition switch.

I hope helped.