TRNW-2: 4L60E with SSB code

[Mark Puccinelli]

If the voltage is stair stepping slowly that usually means the module is
bad.

On Fri, Oct 3, 2025 at 8:19 AM Tod Chretien via trnw2 <trnw2 at trnw.net>
wrote:

> Group,
>
> I have this 1999 Silverado with a P0758 SSB circuit code.
>
> The solenoid resistance is 21 ohms.
>
> With my scope hooked to the SSA and SSB control wires along with a
> battery ground, both solenoids have .4 volts when commanded on, which
> seems a bit high. Like the ground the PCM is providing isn't good enough.
>
> When the solenoids are off I have battery voltage flowing through them,
> which eliminates the ignition switch.
>
> The code actually sets on the 2-3 shift which is delayed. While
> monitoring the shift solenoid control circuit on a scope, SSB voltage on
> the 2-3 shift goes from .4 volts to battery voltage really slow. Usually
> the change from on to off is instantaneous. I have never seen one
> release the ground so slowly. The transmission eventually makes the 2-3
> shift when the SSB voltage finally reaches battery voltage, but the
> P0758 code sets and then it has 3rd gear starts. Until you cycle the key
> which starts the whole process over again.
>
> As anyone seen anything like this? Am I correct to assume it's the PCM?
>
>
> --
> Best Regards,
> Tod Chretien
> TRNW Inc.
> https://www.trnw.net
>
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-- 
*Mark Puccinelli*
*Product Support Technician*
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