What P0974 means
High-voltage fault in the control circuit of shift solenoid A.
How the engine computer detects it
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 transmission 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.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- 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
Common causes
- Open coil or broken wire where the maker reports opens under the high code (GM six-speed) Most likely
- Control wire shorted to a supply voltage Possible
- Spread or corroded pins at the transmission connector Possible
- Faulty driver stage in the control module Less likely
How to diagnose P0974
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: shift solenoid a, wiring harness, tcm.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 9
- Transmission
- 74
- Specific fault
Questions drivers ask
Can I drive with code P0974?
If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.
Will my car pass an emissions inspection with P0974?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0974 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.