Experiencing transmission issues with your 1999 Mazda Protege? You might be encountering problems like harsh shifting or failure to shift into overdrive, accompanied by the flashing “OD Off” light and an OBD2 code P0771. This article will guide you through understanding and potentially resolving this issue yourself, saving you significant repair costs. Many Mazda Protege owners have faced this frustrating situation, and fortunately, a DIY fix might be within your reach.
Understanding OBD2 Codes for Your 1999 Mazda Protege and the P0771 Code
The On-Board Diagnostics II (OBD2) system in your 1999 Mazda Protege is designed to monitor various vehicle systems, including the transmission. When a problem is detected, the system stores diagnostic trouble codes (DTCs) that can be accessed with an OBD2 scanner. The P0771 code is a Mazda-specific OBD2 code that indicates “Shift Solenoid ‘E’ Stuck Off.” This means the Powertrain Control Module (PCM) has detected a malfunction in the Shift Solenoid E circuit, which is crucial for controlling gear shifts within your automatic transmission.
Diagnosing the P0771 Code on a 1999 Mazda Protege
The symptoms associated with a P0771 code on your 1999 Mazda Protege can be quite noticeable. Common signs include:
- Harsh Shifting: You might feel rough or jerky shifts, particularly between 1st and 2nd gear.
- Failure to Shift into Overdrive: The car may not shift into the highest gear (overdrive), leading to higher engine RPMs at highway speeds. In the original case, the vehicle was revving at 3000 RPM at 55 mph.
- Flashing “OD Off” Light: The Overdrive Off indicator light on your dashboard may flash.
- Reduced Fuel Economy: Inefficient shifting can lead to lower gas mileage. The original poster noted around 20 MPG in mixed driving before the fix.
Faced with these symptoms and the P0771 code, many car owners understandably seek professional help. Transmission shops often quote hefty repair costs, sometimes reaching upwards of $2,500. Even lower quotes can still be around $1,200. However, before committing to expensive repairs, consider a DIY approach that could save you a significant amount of money.
DIY Fix: Replacing the Shift Solenoid E on Your 1999 Mazda Protege
For those willing to tackle a bit of DIY auto repair, replacing the Shift Solenoid E can be a viable solution for the P0771 code on a 1999 Mazda Protege. The transmission used in the 1999 Mazda Protege is the FN4-EL, which is similar to the Ford Focus 4F27E transmission.
Here’s a step-by-step guide based on a successful DIY repair:
Tools You’ll Need:
- Socket wrench
- Crescent wrench
- Funnel
- Rags
- Drain pan
- New transmission filter
- New transmission pan gasket
- New Shift Solenoid E
- Transmission fluid
Steps to Replace the Shift Solenoid E:
- Drain Transmission Fluid: Locate the drain bolt on the transmission pan and loosen it with a crescent wrench. Position a drain pan underneath and allow the fluid to drain completely. Be careful as transmission fluid can damage paint and is difficult to clean.
- Remove Transmission Pan: Using a socket wrench, remove all the bolts holding the transmission pan in place. Carefully lower the pan, as there will still be some fluid inside.
- Clean Pan and Magnet: Clean the transmission pan and remove any old gasket material. Also, clean the donut-shaped magnet located in the pan. Inspect for any unusual metal shavings, which could indicate more serious transmission wear.
- Locate and Replace Shift Solenoid E: Identify the Shift Solenoid E. In the 1999 Mazda Protege FN4-EL transmission, it is typically the top, middle solenoid on the passenger side of the valve body, identifiable by the blue and black wire connector. Disconnect the wire connector and remove the four bolts holding the solenoid’s retaining plate. Remove the old solenoid and install the new Shift Solenoid E, lubricating the O-rings with transmission fluid before installation.
.JPG) - Replace Transmission Filter: Since you have the pan off, it’s a good time to replace the transmission filter. Remove the old filter and install the new one.
- Reinstall Transmission Pan: Place the new transmission pan gasket and reinstall the pan. Tighten the bolts to the specified torque.
- Refill Transmission Fluid: Using a funnel, refill the transmission with fresh transmission fluid through the dipstick tube. The original repair used approximately 3.5 quarts.
- Check Fluid Level: Start the engine and shift through all gears several times. Then, check the transmission fluid level using the dipstick and add more fluid as needed to reach the correct level.
Positive Outcome and Cost Savings
After completing these steps, test drive your 1999 Mazda Protege. In the original repair case, this DIY fix successfully resolved the P0771 code, eliminated the “OD Off” light, and restored proper shifting. Engine RPMs at highway speeds returned to normal (dropping to 2,500 RPM at 55 mph), and fuel economy likely improved.
By undertaking this DIY repair, you can potentially save a significant amount of money compared to professional transmission shop quotes. The cost of parts (shift solenoid, filter, gasket, fluid) is considerably less than the labor charges for a full transmission repair.
Conclusion:
If you are facing OBD2 code P0771 and transmission shifting problems with your 1999 Mazda Protege, replacing the Shift Solenoid E is a repair worth considering. With basic tools and a bit of mechanical inclination, you can potentially fix this issue yourself, saving hundreds or even thousands of dollars. Always ensure you are using the correct parts and follow safety precautions when working on your vehicle.
