P0C23Electric/Auxiliary Transmission Fluid Pump Control Module Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0C23 is set by the controlling module, usually the PCM, TCM or hybrid controller, when the circuit to the auxiliary pump control module is open. J2012 does not name the line further; in practice it is the command or enable wire. Ford's 2016 F-150 2.7L bulletin shows such a command: the PCM drives the pump with a duty cycle that a scan tool can vary from 20 to 90 percent. GM's ELR pump controller only runs its phase tests while a wake-up signal is on. No manufacturer publicly documents P0C23 itself. With the line open the pump gets no command and stays off, so auto-stop is disabled and pressure support is missing. P0C24 and P0C25 are the low and high variants, P0C2B to P0C2E the feedback line in the other direction.
- What you may notice
- Start-stop no longer works
- MIL or transmission warning
- Harsh engagement after an engine stop
- Likely causes
- LikelyOpen command or enable wire between controller and pump module
- PossiblePushed-out or corroded terminal at the pump module or controller connector
- RareInput stage of the pump control module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.