P0700 Code Fix Guide: The Shocking Truth Behind This Transmission Error

If your car’s check engine light has turned on and a scan reveals the P0700 code, it means there’s an issue with the transmission control system. This diagnostic trouble code (DTC) doesn’t point to a specific fault by itself—it simply signals that your vehicle’s Transmission Control Module (TCM) has detected a problem and has requested the Malfunction Indicator Light (MIL) to be turned on.

In most cases, the P0700 code appears alongside other transmission-related codes that help pinpoint the real issue. Whether you’re driving a Chevy, Dodge, Subaru, or Honda, this code should not be ignored. It could indicate anything from a minor electrical glitch to a serious mechanical failure.

In this guide, we’ll explain:

• What the P0700 code actually means,
• What causes it,
• How to diagnose and fix it,
• And whether it’s safe to keep driving your car.

Let’s decode it step by step.

What Does the P0700 Code Mean?

The P0700 code stands for “Transmission Control System – Malfunction”. When this code appears, it’s not telling you the exact problem—it’s more like a red flag from the Transmission Control Module (TCM), saying, “Something’s wrong, check the other codes.”

Here’s how it works:

• The TCM monitors your transmission’s performance.
• If it detects a fault—such as improper shifting, sensor failure, or electrical issues—it records a trouble code and alerts the Engine Control Module (ECM).
• The ECM then stores the P0700 code and turns on your check engine light.

📌 Important: The P0700 code is often accompanied by other codes like P0715, P0720, or P0740. These secondary codes help identify the root cause of the issue.

In simple terms, P0700 means your transmission system has reported a problem—but you’ll need further diagnostics to understand exactly what that problem is.

Common Symptoms of a P0700 Code

When your car throws a P0700 code, it’s usually more than just a light on your dashboard—it often comes with noticeable changes in how your vehicle behaves. Recognizing these symptoms early can help prevent serious damage to your transmission system.

🔍 Most Common Signs Include:

• Check Engine Light (CEL) – The most obvious and immediate sign.
• Transmission Limp Mode – The vehicle may limit gear shifting to prevent further damage.
• Hard or Delayed Shifting – Rough gear changes, or delayed engagement when accelerating.
• Poor Fuel Economy – A malfunctioning transmission system can strain the engine.
• Engine Stalling or Shuddering – Especially when shifting into gear.

If you’re noticing these issues, it may be time to check your OBD2 port and plug in a diagnostic scanner. Not sure how? Our detailed guide on how to read OBD-II codes can walk you through it step-by-step.

Also, reviewing your vehicle’s OBD2 trouble codes list can help identify related problems, such as a failing MAP or MAF sensor that might contribute to the transmission issue.

What Causes the P0700 Code?

The P0700 code is a generic transmission-related warning, but the actual cause can vary depending on the vehicle’s make, model, and condition. It’s often triggered by a fault within the Transmission Control Module (TCM) or related components that affect how your transmission operates.

⚠️ Common Causes of the P0700 Code:

1. Faulty Transmission Control Module (TCM)
   The TCM is the brain behind your automatic shifting. When it malfunctions, it sends a request to the Engine Control Module (ECM) to trigger the P0700 code. You can learn more about what a car transmission is here.
2. Low or Dirty Transmission Fluid
   Contaminated or low fluid levels can lead to poor transmission performance. Not sure about the difference between transmission and transaxle fluid? See our guide on transaxle fluid vs transmission fluid.
3. Faulty Sensors (MAP/MAF/TPS)
   Sensors like the MAP sensor, MAF sensor, or even the throttle position sensor (TPS) can send incorrect signals, causing the transmission to behave abnormally. These errors can trigger a chain reaction leading to codes like P0700.
4. Wiring Problems or Corroded Connectors
   Frayed wiring or damaged connectors between the TCM and ECM can disrupt signal flow, causing transmission faults.
5. Related DTCs Present
   Often, the P0700 code shows up alongside other codes like P2172. You can read about what the P2172 code means and how it connects to sensor and airflow issues that might affect shifting performance.

How to Diagnose the P0700 Code

Diagnosing a P0700 code isn’t always straightforward, because the code itself only tells you that there’s an issue in the transmission control system—not what that issue is. To get to the root cause, you’ll need to perform a structured diagnostic process using an OBD-II scanner and some basic mechanical checks.

🛠 Step-by-Step Diagnosis Guide:

Review OBD2 Trouble Code References
For a better understanding of each code and what they mean, our OBD2 trouble codes hub is a great place to start. It helps you connect related issues and avoid replacing the wrong parts.

Use an OBD2 Scanner
Begin by connecting an OBD-II scanner to your vehicle’s diagnostic port. If you’re unfamiliar with how this works, check out our guide on how to use an OBD2 scanner. This will pull up all stored trouble codes, not just P0700.

Look for Accompanying Codes
Codes like P0715 (Input Shaft Speed Sensor) or P0720 (Output Speed Sensor) often appear with P0700. These secondary codes are crucial to narrowing down the exact issue.

Inspect Transmission Fluid
Low, dirty, or burnt transmission fluid can cause shifting problems. If you’re unsure about what kind of fluid your car uses, refer to our breakdown of transaxle fluid vs transmission fluid.

Check Electrical Connections
Visually inspect wiring and connectors between the Transmission Control Module (TCM), Engine Control Module (ECM), and sensors. Look for corrosion, loose pins, or damaged harnesses.

Evaluate Sensor Readings (MAP/MAF)
A faulty MAP sensor or MAF sensor can send incorrect signals that impact how the transmission responds. Cross-check sensor output using the scanner’s live data stream.

How to Fix the P0700 Code

Fixing the P0700 code requires identifying the root cause—which often involves more than just clearing the code. While some issues may be minor, like low transmission fluid, others might need professional repair or even module replacement.

🔧 Step-by-Step Fixes for P0700:

1. Clear the Code and Test Drive
   After diagnosing with an OBD2 scanner, you can try clearing the code. If it doesn’t return, the issue may have been a temporary glitch. However, if it reappears, deeper inspection is needed.
2. Top Off or Replace Transmission Fluid
   Check your vehicle’s fluid level and quality. If the fluid is dark or has a burnt smell, a flush or replacement is recommended. For help deciding on the correct fluid type, see: Transaxle Fluid vs Transmission Fluid.
3. Fix Wiring or Connector Issues
   Damaged wires or corroded connectors can disrupt communication between modules. Repair or replace any faulty connectors near the TCM or sensors.
4. Replace Faulty Sensors
   A bad MAP sensor or MAF sensor can send incorrect data to the transmission system. If these components are out of spec, replacing them can resolve the code.
5. Replace or Reprogram the TCM
   If diagnostics point to a faulty Transmission Control Module, it may need replacement or reprogramming. This is usually a job for a certified technician, especially on modern vehicles with software-dependent modules.
6. Fix Additional DTCs (If Present)
   If your scan also shows codes like P2172, address them first. These might indirectly affect transmission behavior and trigger the P0700 code.

💡 Bonus Tip:

After completing repairs, always perform a final scan and a test drive. This ensures the P0700 code is resolved and that your vehicle’s transmission system is operating normally.

Is It Safe to Drive With a P0700 Code?

Technically, yes—you can drive your car with a P0700 code, but it’s not recommended. While your engine may still run, the transmission system is in distress, and continuing to drive could cause further damage or trigger “limp mode”, which limits your vehicle’s power and gear shifting to prevent system failure.

🚨 Driving Risks Include:

• Sudden loss of acceleration
• Unpredictable gear shifts or no shifting at all
• Overheating transmission
• Potential failure of internal components

🔍 Why Immediate Action Matters:

Delaying the repair can lead to more severe issues—such as clutch pack damage, solenoid failure, or total transmission replacement. These repairs are far more expensive than resolving the root cause early.

If you’re unsure whether to continue driving, consult your vehicle’s fault log using an OBD2 scanner, or learn more about the basics of how to read OBD-II codes for quick self-assessment.

Estimated Repair Costs for P0700 Code

The cost to fix a P0700 code can vary significantly depending on what’s causing the problem. Minor issues—like low fluid or a loose connection—are relatively cheap to fix, while TCM replacement or internal transmission work can cost much more.

Here’s a breakdown of typical repair costs you might expect:

💡 Pro Tip:

Before spending big on transmission repairs, always scan for related trouble codes like P2172 or issues with airflow sensors such as MAP or MAF sensors. Fixing these can sometimes resolve the P0700 code without deep transmission work.

For long-term health, it’s also helpful to understand how long a car battery lasts, since weak batteries can affect module performance and diagnostics.

Vehicle-Specific P0700 Code Insights

While the P0700 code has a universal meaning—transmission control system malfunction—its cause and fix can vary depending on the make and model. Here’s what it typically means on popular vehicles like Chevy, Dodge, Subaru, and more.

🚗 P0700 Code on Chevy (Silverado, Malibu, Cruze)

On Chevrolet models, especially the Silverado or Malibu, the P0700 code is often linked to failed shift solenoids or low transmission fluid. It’s also common for the Transmission Control Module (TCM) to require reprogramming or replacement.

🛠 Recommended fix:
Start with a transmission fluid check, then scan for secondary codes like P0715 or P0740. These point to specific transmission faults.

🚙 P0700 Code on Dodge (Ram 1500, Dakota)

In Dodge vehicles like the Ram 1500, a P0700 code is frequently associated with internal transmission failures or solenoid pack issues. Many drivers also experience limp mode immediately after the light comes on.

📌 If you own a Dodge, learning how to read OBD-II codes can help:
👉 How to Read OBD-II Codes

🚐 P0700 Code on Subaru (Outback, Forester)

In Subaru models like the Outback and Forester, the P0700 code may result from worn valve bodies, failed sensors, or transmission overheating. Subaru CVT systems are sensitive, and neglecting this code can lead to costly repairs.

💡 Don’t overlook airflow sensors—MAP and MAF sensor failures can mimic transmission problems.

🚘 P0700 Code on Honda (Accord, Civic)

In Honda vehicles such as the Accord or Civic, this code often flags electrical issues within the TCM or dirty transmission fluid. Check wiring around the transmission and test the fluid’s condition before replacing parts.

⚠️ Some users also report battery voltage issues contributing to the problem. Learn how long a car battery lasts to avoid weak-voltage-related errors.

🚗 P0700 Code on Chrysler & Jeep (Chrysler 300, Grand Cherokee)

Chrysler vehicles and Jeep Grand Cherokee models commonly throw this code due to internal TCM failures or sensor mismatches. In many cases, a software update or full TCM replacement is required.

🔧 Consider using a professional-grade scanner or refer to our OBD2 Scanner Guide to read deeper transmission-specific DTCs.

People Also Ask – FAQ

Why You Shouldn’t Ignore the P0700 Code

The P0700 code may seem like just another dashboard alert, but it often signals a critical issue within your car’s transmission control system. Ignoring it can lead to further mechanical failure, higher repair bills, and even unsafe driving conditions.

Whether you’re troubleshooting a Chevy Silverado, Subaru Outback, or Dodge Ram, understanding and addressing this code early can prevent major headaches. If you’re new to the world of automotive diagnostics, we also recommend reviewing Wikipedia’s page on OBD-II for a deeper technical background on how these systems work.

At AutocarsBlog.net, we’re committed to delivering accurate, trustworthy, and actionable automotive advice—not just for search rankings, but to help real drivers solve real problems. Our content is backed by research, experience, and a mission to raise the bar for car maintenance education online.

Explore more helpful guides:

• How to Read OBD-II Codes
• What Is a MAP Sensor?
• What Is a Car Transmission?

Stay informed. Stay empowered. Drive with confidence.