P0C24 — Auxiliary Transmission Fluid Pump Control Module Circuit Low

powertrain (engine/transmission)

Is it safe to drive?

Drive with caution Drive only if the transmission still shifts predictably, and avoid highway speeds. Driving with slipping or limp mode accelerates internal wear — every kilometre can add to the final repair bill.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P0C24 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the automatic transmission control for damage, corrosion, chafing or poor contact.
  4. Subsystem check Check for supply voltage at the auxiliary transmission fluid pump control module connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
  5. Subsystem check Check transmission fluid level and condition — dark, burnt fluid points to internal wear.
  6. Subsystem check Read transmission-specific codes and live data (solenoid states, input/output speed) with a capable scanner.
  7. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P0C24 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P0C24 (parts and labor, USD, independent shop rates): Transmission fluid service: $150–$350; Transmission rebuild or replacement: $2,500–$5,500; Valve body repair or replacement: $700–$1,500; Replace a shift solenoid: $300–$800. Overall, fixing P0C24 usually costs between $150 and $5,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Is it safe to drive with P0C24?

Drive only if the transmission still shifts predictably, and avoid highway speeds. Driving with slipping or limp mode accelerates internal wear — every kilometre can add to the final repair bill.

How do I diagnose P0C24 myself?

Start with a scan: confirm P0C24, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the auxiliary transmission fluid pump control module, and verify the suspect component against live data before buying parts.

What are the symptoms of P0C24?

Drivers most often notice: slipping between gears, shuddering at highway speed, Check Engine or transmission warning light on, transmission stuck in one gear (limp mode).

What does OBD2 code P0C24 mean?

Auxiliary Transmission Fluid Pump Control Module Circuit Low (P0C24): a powertrain (engine/transmission) fault affecting the automatic transmission control. Short, gentle driving to a shop is usually possible. Most often caused by valve body wear, wiring or connector faults in the valve body harness, failed shift or pressure control solenoid.

Will P0C24 clear itself?

Sometimes P0C24 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

When your scanner pulls code P0C24, it tells you the transmission control system has spotted an electrical problem with the auxiliary fluid pump circuit. Officially this reads as "Auxiliary Transmission Fluid Pump Control Module Circuit Low," and it falls under the powertrain category since it involves the transmission and its electronic management. The "circuit low" part specifically means the voltage on that circuit has dropped closer to ground than it should, signaling the module or its wiring is not receiving the electrical operating conditions it needs to function.

Modern automatics use an auxiliary transmission fluid pump to maintain oil pressure when the engine is idling or during low-speed maneuvers, especially in vehicles with start-stop systems. That pump is governed by a dedicated control module that monitors voltage and current flow. When the module detects readings that fall below its calibrated minimum — typically after multiple drive cycles — it logs P0C24 and illuminates the check engine or transmission warning light. The stored freeze frame data captures engine speed, load, coolant temperature, and vehicle speed at the moment of failure, giving you a diagnostic snapshot to work from.

Common Symptoms of P0C24

  • Gear slipping or delayed engagement when shifting
  • Noticeable shudder or vibration at highway speeds
  • Check engine or transmission warning lamp illuminated
  • Transmission locked into a single gear, often called limp mode
  • In extreme cases, complete loss of forward or reverse movement
  • Unusual noises from the transmission pan area

What Causes This Fault Code

P0C24 points to several possible culprits, ranked roughly by how often they appear in the field:

  1. Loss of supply voltage to the auxiliary transmission fluid pump control module
  2. Signal wire shorted to ground due to chafed or damaged insulation
  3. Failed auxiliary transmission fluid pump control module itself dragging the circuit low
  4. Wiring or connector problems in the valve body harness
  5. Worn or faulty transmission speed sensor
  6. Damaged shift or pressure control solenoid
  7. Low, contaminated, or degraded transmission fluid
  8. Internal mechanical issues such as worn clutches or torque converter problems
  9. Valve body wear affecting hydraulic control circuits

How to Diagnose P0C24

Working through this code methodically prevents unnecessary parts replacement. Follow these steps in order:

  1. Connect an OBD2 scanner, retrieve P0C24, and record all freeze frame data — this snapshot shows engine conditions when the fault first appeared.
  2. Scan for any related diagnostic trouble codes; overlapping faults often point to the root cause. Check manufacturer technical service bulletins for known software updates or factory remedies that apply to your vehicle.
  3. Perform a thorough visual inspection of the wiring harness and connectors feeding the transmission control system, looking for damaged wires, corrosion, loose terminals, or evidence of heat damage.
  4. Test for proper supply voltage at the auxiliary transmission fluid pump control module connector. Then check resistance from the signal circuit to ground — a reading near zero ohms confirms a short to ground in the wiring.
  5. Inspect transmission fluid level and condition; dark, burnt-smelling fluid suggests internal wear or overheating.
  6. Use a capable scanner to pull transmission-specific codes and view live data, including solenoid states and input/output speed sensor readings.
  7. Clear P0C24 and complete a full drive cycle matching the conditions from your freeze frame. Confirm the code does not return.

Repair Options and Costs

Once you have identified the failing component, here is what you can expect to pay for parts and labor at an independent shop:

  • Transmission fluid service (drain and fill or flush): $150–$350
  • Valve body repair or replacement: $700–$1,500
  • Shift solenoid replacement: $300–$800
  • Transmission rebuild or full replacement: $2,500–$5,500

Total repair costs for P0C24 typically fall between $150 and $5,500 depending on which part failed. Always pursue the cheapest plausible cause first — wiring shorts and fluid issues are far more common than a complete transmission failure.

Driving Safety Verdict

Treat P0C24 with caution. If the transmission still shifts predictably and no warning light is flashing, short trips on lower-speed roads are acceptable while you arrange diagnosis. However, continued driving with slipping gears, shuddering, or limp mode active accelerates wear on internal components and can turn a minor fix into a major transmission rebuild. The safest approach is to have this code investigated promptly and avoid sustained highway driving until the issue is resolved.

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