P0EC7A/C Power Supply Relay Control Circuit Low
- Generic OBD-II code · Powertrain
- How the car detects it
- P0EC7 is set when the control line of the relay feeding the A/C reads too low a voltage, usually because it is shorted to ground. What the driver feels depends on how the coil is switched: with a low-side driver a grounded line can keep the relay energised even with the A/C off, while with a high-side driver the relay simply cannot be switched on. No manufacturer documents P0EC7 publicly. As a comparison, Mitsubishi monitors a relay-fed supply on its throttle actuator (P0657): with battery voltage above 8.3 V, the switched line must not sit at or below 6.0 V for 0.35 seconds. Open-circuit code: P0EC6; high counterpart: P0EC8; clutch relay analogue: P0646.
- What you may notice
- A/C power stays on with A/C switched off, or never switches on
- Possible battery drain while parked if the relay stays energised
- Likely causes
- LikelyRelay control line chafed and shorted to ground
- PossibleShorted turns in the relay coil
- RareOutput stage of the module stuck low
- Repair
- Medium · Usually a job for a workshop.Typical cost: €20 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.