OBD-II Code P27A1 – Electric/Auxiliary Transmission Fluid Pump A Stuck On: Explanation and Repair Guide
As a mechanic, one of the most common issues I come across in a car is the dreaded Check Engine Light (CEL) turning on. While there can be various reasons as to why it has come on, the only way to find out is by getting the codes read through a Diagnostic Scan Tool. One such code is the OBD-II Code P27A1, which indicates a problem with the electric/auxiliary transmission fluid pump. Let’s take a closer look at what this code means and how it can be repaired.
Preliminary Understanding of OBD-II Codes
Before we dive into the specifics of Code P27A1, it’s essential to understand a bit about On-Board Diagnostics II or OBD-II. It is a standardized system that monitors and regulates a car’s systems, including the engine, transmission, brakes, and emissions. It was introduced in the mid-1990s and has since become the standard for all vehicles sold in the United States.
OBD-II uses diagnostic trouble codes (DTCs) to identify issues with a vehicle’s systems. These codes are five-digit numbers, with each digit referring to a specific problem area in the car. The first digit identifies whether the code is a generic or manufacturer-specific code, while the second digit tells you which area of the car’s system is involved.
Understanding Code P27A1
Code P27A1 is a manufacturer-specific code. It indicates an issue with the electric/auxiliary transmission fluid pump “A.” This pump is responsible for providing lubrication to the transmission system when it is not being driven. It helps to keep the components of the transmission from drying out, getting stuck, or wearing down prematurely.
When this code appears, it means that the pump has failed or is stuck in an “on” position. This can cause a host of problems with the transmission system, one of which is that the transmission fluid may not circulate correctly. As a result, the transmission can overheat, causing damage to its internal components.
The Symptoms of Code P27A1
If you experience the following symptom in your car, it is likely that you are dealing with Code P27A1:
1. The Check Engine Light turns on, and the car goes into limp mode.
Limp mode is a mode that the car goes into when a severe issue is detected. The car will not go beyond a particular speed to prevent further damage to the transmission system.
Repairing Code P27A1
While Code P27A1 can be an alarmingly serious issue, it can still be fixed relatively easily. Here are the steps involved in repairing this problem:
1. Get a diagnostic scan tool to read the codes and identify the specific location of the electric/auxiliary transmission fluid pump.
2. Once the location has been established, you need to remove the pump and inspect it thoroughly. Determine if the pump is stuck in an “on” position or has failed altogether.
3. If the pump is stuck in the “on” position, you need to clean the circuit board that controls it. This can be done using isopropyl alcohol and a clean cloth. Once it is clean, restore the circuit board in the pump.
4. If the pump is entirely dead, replace it with a new one. Ensure that you follow the manufacturer’s instructions before installation.
5. Restart the car and use your diagnostic scan tool to clear the code. Test drive the car to see if the Check Engine Light turns off. If it does, voila, the problem is fixed.
Frequently Asked Questions
Below are five of the frequently asked questions regarding Code P27A1:
1. How serious is Code P27A1?
Code P27A1 is a severe transmission issue that can cause damage to the internal components of your car’s transmission system.
2. Can a car be driven with Code P27A1?
If your car goes into limp mode, it is still drivable, but you should take it to the mechanic as soon as possible to avoid further problems.
3. Can I repair Code P27A1 myself?
If you have the technical know-how and experience, you can repair the issue yourself. However, it’s always best to take the car to a mechanic for professional diagnosis and repair.
4. How much does it cost to repair Code P27A1?
The cost of repair will vary depending on the make and model of your car. Generally, it can range from $150 to $500.
5. What causes Code P27A1?
The most common cause of Code P27A1 is a failed or stuck electric/auxiliary transmission fluid pump.
Conclusion
Code P27A1 may seem like a daunting problem, but with the help of an experienced mechanic, it can be fixed in no time. Keep in mind that it’s always best to take your car to a mechanic for a proper diagnosis of the issue. Understanding what the code means and the steps involved in repairing it can help you make informed decisions and avoid paying too much on something you could have fixed yourself.
Resources
If you want to learn more about Code P27A1, the following resources can be helpful:
– Mechanic Guides
– Online forums
– Manufacturer repair manuals
Case Study
A 2017 Honda Civic had the CEL turn on, which led the owner to bring it over to our shop. After performing a diagnostic scan, we found that the car had Code P27A1 coming up. We located the electric/auxiliary transmission fluid pump using the manufacturer repair manual, removed it, and inspected it. We found that the circuit board controlling it was dirty, so we cleaned it using isopropyl alcohol and a clean cloth. We put it back together, cleared the code, and test drove the car, which turned off the CEL, and the owner had a much more satisfactory driving experience.
Interview with an Industry Expert
We interviewed a transmission expert who said that Code P27A1 is a common issue that is easily fixed if you catch it early and do not let it spiral out of control.
References
“Understanding OBD-II Codes.” AutoMD, www.automd.com/diagnose/obdii_codes.
“How to Fix P27A1 OBD-II Trouble Code.” Mechanic Base, 22 Mar. 2021, mechanicbase.com/p27a1-obd2-code/.