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Shift Solenoid A and B Circuit - Electrical

01-26-2004, 11:03 AM
I have a Denali 2002 and noticed some slow down and a light would come on in the car to "check engine". I had a friend do a test with the OBD II and it showed 5 faults:

1) PO740 - TCC Circuit malfunction
2) PO753 - Shift Solenoid A Circuit Electrical
3) PO758 - Shift Solenoid B Circuit Electrical
4) PO785 - Shift/Timing Solenoid Malfunction
5) PO860 - Manufacturer Contrl. Transmission

Shall I replace the Shift Solenoid A & B? If so Do you know where this is located on the SUV?

I am assuming if this is replaced it will probably correct the others.

Thank you,


03-06-2004, 10:05 AM
You should have more diagnosis done before replacing any solenoids. I own a tranny shop and often find this many codes can indicate a number of different things.

If you have access to an OBDII scanner. Clear all the codes, drive the Yukon and see which code comes back first.

If you're willing take your Yukon by a reputable tranmission shop and have them check it to determine the root cause of these codes.

Good luck

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