P0974Shift Solenoid A Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- High-voltage fault in the control circuit of shift solenoid A. What it covers depends on the maker. Ford reserves it for a short to power on SSA, because an open SSA circuit sets P0750. GM six-speeds put both an open and a power short of the mode 2 solenoid here: 1.2 of 1.5 s, MIL only after two trips. The Saab 9-4X 6T70 waits 2 s, Type B, and then blocks 1st gear. GM's Allison 1000 tables of 2016 and 2023 treat it as a pure power short (0.39 ohm or less, 3 samples, 75 or 60 ms) and report opens separately. Saab's Aisin gearbox in the 9-5 (2010) sets it when solenoid valve 2 reads off while commanded on, 100 ms five times, Type A. Ground-side faults are P0973.
- What you may notice
- MIL on, on GM six-speeds only after a second faulty trip
- First gear locked out, start-off in a higher gear
- Missing or wrong shifts, possibly limp mode
- Likely causes
- LikelyOpen coil or broken wire where the maker reports opens under the high code (GM six-speed)
- PossibleControl wire shorted to a supply voltage
- PossibleSpread or corroded pins at the transmission connector
- RareFaulty driver stage in the control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.