GM's skip-shift (CAGS) on manual gearboxes such as the T56 and TR6060 uses an engine-module solenoid that, at light load, blocks the way from 1st into 2nd so the driver shifts 1 to 4; the 1-4 lamp shows it (P0804). The engine module drives the solenoid with a low-side driver; P0803 is the open circuit. P080B would be the range or performance fault of this circuit: electrically plausible, but outside the expected range for the command – for example a coil resistance outside its window, a partial short or contact resistance. No manufacturer document available to us uses it: GM's tables from 2006 to 2019 check the solenoid only electrically (P0803 open, P080C short to ground, P080D short to positive). CARB requires a functional check of outputs where feasible. The lockout may then work unreliably.
Medium severity. Can I keep driving?Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.
Symptoms
- Check engine lamp (depends on manufacturer)
- 1-4 lockout works not at all or only sometimes
- Otherwise no change in driving
Most likely causes
- Solenoid coil with shorted turns or resistance out of range
- Retrofitted skip-shift eliminator with the wrong value
- Corroded connector at the gearbox (contact resistance)
- Control module or software
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P080B means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 8: Transmission
- 0B: Specific fault in that system
Frequently asked questions
Can I keep driving with code P080B?
Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.
What causes code P080B?
The most common causes are: solenoid coil with shorted turns or resistance out of range; retrofitted skip-shift eliminator with the wrong value; corroded connector at the gearbox (contact resistance).
Related codes
- P0803Upshift/Skip Shift Solenoid Control Circuit
- P080CUpshift/Skip Shift Solenoid Control Circuit Low
- P080DUpshift/Skip Shift Solenoid Control Circuit High
- P0804Upshift/Skip Shift Lamp Control Circuit
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.