P0974: owner reports and bulletins

Powertrain (generic, all makes). We haven't written the explanation for this code yet. Below is what owners and manufacturers have filed with NHTSA.

Got P0974 on your scanner? Tell the mechanic your year, make, model and any symptoms and you'll get the likely cause and what to check first. Ask about this code.

What owners report to NHTSA

No consumer complaints filed with NHTSA mention P0974. That usually means it's rare, or owners don't quote the code when they file.

Manufacturer service bulletins that name P0974

2 technical service bulletins and manufacturer communications filed with NHTSA mention P0974, from 1 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • HINO CONVENTIONAL LDT W/ JO5E (2013, 2014, 2015, 2012), bulletin 10118108: TT-15-014 The transmission DTC?s P0974 and P0986, may be found on 12MY-15MY COE models. There could also be a complaint of low power and erratic shifting. These diagnostic codes may be set due to low voltage between the …
  • HINO CONVENTIONAL MODELS (2012, 2013, 2014, 2015), bulletin 10184856: 2012-2015 COE Transmission DTC P0974 - P0986, may be found on, There could also be a complaint of low power and erratic shifting. These diagnostic codes may be set due to low voltage between the transmission case and the…

Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.