The P0C27: Auxiliary Transmission Fluid Pump Motor Current Low fault code indicates that the current being drawn by the auxiliary transmission fluid pump motor is lower than expected. This can be caused by a faulty motor current sensor, issues within the electrical system, or a malfunction in the pump motor itself. Low current could result in improper functioning of the pump, affecting the cooling of the transmission fluid.
P0C27 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0C27: Auxiliary Transmission Fluid Pump Motor Current Low |
| Is it serious? | Yes, low current can lead to pump failure and impact transmission cooling. |
| Possible causes | – Low current reading from the motor – Faulty motor current sensor – Electrical system issues |
| How to diagnose? | – Measure the motor current – Test the motor current sensor – Inspect the electrical system |
P0C27 Meaning
The P0C27 code means that the auxiliary transmission fluid pump motor is drawing less current than it should, which may be caused by a faulty current sensor, wiring issues, or problems within the electrical system. Low current can prevent the motor from operating efficiently, leading to improper circulation of transmission fluid and potential transmission overheating.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional related codes, especially those concerning electrical system or motor performance. | OBD-II Scanner |
| Measure the Motor Current | Use a multimeter or diagnostic tool to measure the current being drawn by the auxiliary transmission fluid pump motor. Compare the readings with manufacturer specifications. | Multimeter, Diagnostic Tool |
| Test the Motor Current Sensor | Use a multimeter or diagnostic tool to test the motor current sensor. Verify that the sensor is providing accurate readings. If the sensor is faulty, replace it. | Multimeter, Diagnostic Tool |
| Inspect Wiring and Connections | Visually inspect the wiring and connections to the motor and sensor for signs of damage, corrosion, or loose connections that could result in low current. Repair or replace as necessary. | Flashlight, Multimeter, Wiring Diagram |
| Check the Electrical System | Inspect the vehicle’s electrical system, including the alternator, battery, and voltage regulator, to ensure they are providing proper voltage and current to the motor. | Multimeter, Flashlight, Electrical System Tools |
| Test the Pump Motor | If the current sensor and wiring are functioning correctly, test the auxiliary transmission fluid pump motor for any internal issues that may be affecting its current draw. Replace the motor if needed. | Diagnostic Tool, Pump Testing Equipment |
| Clear the Code and Test Drive | After repairs, clear the fault code using an OBD-II scanner and perform a test drive to ensure the issue is resolved and the motor is working properly. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the system to confirm that the P0C27 code does not return. | OBD-II Scanner |
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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)