P0C23 code meaning
Electric/Auxiliary Transmission Fluid Pump Control Module Circuit/Open
Powertrain system Generic code P0Cxx codes Check engine light
What P0C23 means
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.
P0C23 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0C23
- Start-stop no longer works
- MIL or transmission warning
- Harsh engagement after an engine stop
Common causes of P0C23
- Most likelyOpen command or enable wire between controller and pump module
- PossiblePushed-out or corroded terminal at the pump module or controller connector
- Less likelyInput stage of the pump control module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Aux trans pump control moduleWiring harnessTCM
What each part of P0C23 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C | Area: hybrid propulsion. |
| 23 | The exact fault in that area. |
What to do next
- Note P0C23 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0C23
What does P0C23 mean?
P0C23 means "Electric/Auxiliary Transmission Fluid Pump Control Module Circuit/Open". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C23?
Drive gently and only to a workshop. With P0C23 the car can go into limp mode (reduced power) to protect itself.
Will P0C23 fail an emissions test?
Yes, it can. P0C23 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0C23 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0C23 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.