P1738 3-4 Shift Malfunction

How to Diagnose and Solve P1738 3-4 Shift Malfunction Issues

Are you experiencing a P1738 3-4 shift malfunction in your vehicle? Don’t worry, you’re not alone. This common issue can be a real headache, but with the right knowledge and tools, you can diagnose and solve it yourself. Let’s dive in!

Understanding the P1738 3-4 Shift Malfunction

First things first, let’s understand what a P1738 3-4 shift malfunction is. This error code is typically associated with automatic transmissions and indicates a problem with the shift between the third and fourth gears. It’s like your car is trying to tell you, “Hey, I’m having trouble shifting gears here!”

Common Symptoms

How do you know if your car is suffering from this issue? Here are some common symptoms:

– Difficulty shifting between third and fourth gear
– The transmission slipping
– Check engine light is on
– Decreased fuel efficiency

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Diagnosing the P1738 3-4 Shift Malfunction

Now that we know what we’re dealing with, let’s move on to diagnosing the problem. Remember, diagnosing is like playing detective – you’re looking for clues to solve the mystery!

Step 1: Check the Transmission Fluid

The first step in diagnosing a P1738 3-4 shift malfunction is to check the transmission fluid. Low or dirty transmission fluid can cause shifting problems. So, pop the hood and check the fluid level and its condition. If it’s low or dirty, it might be time for a change.

Step 2: Use a Diagnostic Tool

Next, use a diagnostic tool to read the error codes from your car’s computer. This tool, also known as an OBD-II scanner, can provide valuable information about what’s going wrong in your vehicle.

Solving the P1738 3-4 Shift Malfunction

Once you’ve diagnosed the problem, it’s time to roll up your sleeves and get to work. Here’s how you can solve the P1738 3-4 shift malfunction.

Step 1: Change the Transmission Fluid

If your transmission fluid was low or dirty, changing it could solve the problem. This is a relatively simple task that you can do at home with the right tools and a little patience.

Step 2: Replace the Shift Solenoid

If changing the fluid doesn’t solve the problem, the issue might be with the shift solenoid. This component controls the flow of fluid to the transmission and can cause shifting problems if it’s faulty. Replacing it might be a bit more complex, but it’s still something you can do at home if you’re comfortable with car repairs.

Step 3: Seek Professional Help

If all else fails, it might be time to seek professional help. A qualified mechanic can diagnose and solve complex transmission issues, ensuring your car is safe and reliable.


Dealing with a P1738 3-4 shift malfunction can be frustrating, but with a little knowledge and some DIY spirit, you can diagnose and solve the problem yourself. Remember, your car is like a puzzle – with the right pieces, you can solve any problem!


1. What causes a P1738 3-4 shift malfunction?

A P1738 3-4 shift malfunction can be caused by several factors, including low or dirty transmission fluid, a faulty shift solenoid, or a problem with the transmission control module.

2. Can I drive my car with a P1738 3-4 shift malfunction?

While it might be possible to drive with this issue, it’s not recommended. The malfunction can cause further damage to your transmission and decrease your car’s performance and fuel efficiency.

3. How much does it cost to fix a P1738 3-4 shift malfunction?

The cost to fix this issue can vary greatly depending on the cause. Simple fixes like changing the transmission fluid can be relatively inexpensive, while more complex repairs like replacing the shift solenoid or transmission control module can be more costly.