C0740Electric Power Steering Voltage Supply
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- C0740 is not publicly documented by any carmaker; publicly available J2012 lists, NHTSA bulletins and maker indexes do not contain it. The title concerns the heavy supply feed of an electric steering, which draws high currents when the wheel is turned at standstill. GM bulletin PIT5405C for 2014-17 Silverado, Sierra, Tahoe, Suburban, Yukon and Escalade shows what a weak feed does: reduced assist, kickback in the wheel, even stalling and blank displays, traced to a poor body ground, a battery cable shorting on the starter shield, high-resistance battery connections, a weak battery or a loose main power and ground connector at the rack. GM logs device power faults there as C0800. NXP describes EPS control units with integrated undervoltage monitoring that limit or stop assist when supply sags.
- What you may notice
- Assist weakens or cuts out at low speed and full lock
- Steering wheel jerks, other displays flicker
- Likely causes
- LikelyLoose or corroded main power or ground connection at the rack
- PossibleDischarged or failing battery, high-resistance battery cables
- RareBattery cable shorting elsewhere or poor body ground
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.