P0758 - 2-3 Shift Solenoid Circuit Electrical

[bweiser86]

Well I bought a '99 Deville a while back, and it's been a nonstop headache and has been in the shop more often than I've actually been able to drive it.

Currently, I'm pulling the diagnostic code "P0758 - 2-3 Shift Solenoid Circuit Electrical". What does this mean? Is this going to be another 1,000 dollar repair for me?

This is what happened RIGHT before the "Service Engine" light came on. "Traction Engaged" kept appearing in the display, and the car was turning into a real jerky ride as a result of the traction. I was driving on SMOOTH ROAD in NORMAL weather conditions. There's no reason traction should've come on. This kept happening in increasing frequency until this light came on. Now it feels like the car is stuck in the wrong gear, even though I can easily switch gears.

It feels like my horsepower has been cut in half. It's a lot tougher to accelerate when it used to be a breeze to get the car moving. The ride is bumpy, when before it was smooth. If I take my foot of the brake while stopped the car won't even move, when before the light came on it would creep forward slowly.

I already had the transmission worked on. Here's a list of what's been done since I bought this car.

Service Description:

Converter Lockup

Solenoid- Removed + Replaced

Torque Converter

TCC Sonax Valve

TCC Solenoid

Side Filter

Ream + Install TCC Sonax Valve

Service Description:

Replace Serpentine belt, spark plugs, fuel filter, axle shaft, recharge freon

Service Description: Replace Radiator, sensors, extension valve replaced/evacuated and recharged freon, oil change

Please help I've already spent 2,000 dollars in repairs for a used car.

[bweiser86]

Not a single person as any input?

[KHE]

Something is wrong in the shift solenoid circuit wiring. Maybe a pinched wire or a broken solenoid. From your description, it looks like you had the solenoid replaced. It's possible the wiring got pinched. Definitely not a $1000 repair bill unless you let whomever worked on it weasle out of fixing it right...

[BodybyFisher]

The 2-3 solenoid valve controls the transmission fluid to the 2-3 shift valve. Ignition voltage is supplied to the solenoid. The PCM output driver provides the ground. When the shift solenoid voltage is commanded on, the PCM senses 0 volts, when it is commanded off, the PCM senses ignition voltage. When the PCM detects voltage limits that do not meet the calibration, then DTC P0758 sets.

When the PCM detects an OPEN, a short to ground or a shorts to power on the 2-3 shift solenoid valve circuit the code is set.

The following actions are taken

MIL lights

Service Engine and Service Trans lights

PCM commands second great starts (this is your sluggish feeling)

PCM commands default line pressure (this is your rough shifting)

PCM disables steady state adapts

PCM disables garage shift adapts

PCM inhibits TCC

PCM inhibits torque management

This is either a bad 2-3 shift solenoid or the associated wiring or a bad connection at the main tranmsission plug. Replacing the shift solenoids (there are 2) is an easy job, they are in the lower pan, but the lower control valve must come off and there are a few check balls that must go back correctly.