Your Dodge vehicle’s Transmission Control Module (TCM) plays a crucial role in ensuring smooth gear shifts and overall transmission performance. When the TCM detects an issue, it triggers fault codes that can help diagnose and resolve the problem. Understanding these codes and their implications is essential for keeping your Dodge running smoothly.
In this post, we’ll explore some of the most common TCM-related fault codes, their symptoms, and how to address them effectively.
Top TCM Fault Codes in Dodge Vehicles
1. P0700: Transmission Control System Malfunction
This generic code indicates a problem within the transmission control system. It often serves as a “gateway” code, prompting further diagnosis to pinpoint the specific issue.
- Symptoms: Check engine light (CEL), limp mode, harsh shifting.
- Fixes: Scan for additional codes to identify the root cause, inspect the TCM, and check wiring connections.
2. P0715: Input/Turbine Speed Sensor Circuit Malfunction
This code signifies an issue with the input speed sensor, which monitors the rotational speed of the transmission input shaft.
- Symptoms: Delayed or erratic shifting, transmission slipping.
- Fixes: Inspect and replace the input speed sensor if necessary.
3. P0720: Output Speed Sensor Circuit Malfunction
The TCM generates this code when there’s a problem with the output speed sensor, which tracks the speed of the transmission’s output shaft.
- Symptoms: Difficulty shifting gears, incorrect speedometer readings.
- Fixes: Check the sensor’s wiring and replace it if damaged.
4. P0730: Incorrect Gear Ratio
This code appears when the TCM detects that the actual gear ratio does not match the expected ratio.
- Symptoms: Harsh shifting, poor fuel efficiency, limp mode.
- Fixes: Inspect the transmission fluid, solenoids, and clutch components for damage.
5. P0750 – P0770: Shift Solenoid Malfunctions
These codes correspond to various shift solenoid failures. Solenoids control fluid flow within the transmission for gear shifting.
- Symptoms: Stuck gears, delayed shifts, transmission slipping.
- Fixes: Test and replace faulty solenoids or repair the associated circuits.
6. P0841: Transmission Fluid Pressure Sensor/Switch A Circuit Range/Performance
This code indicates a fault with a pressure sensor or switch monitoring the transmission fluid’s pressure.
- Symptoms: Harsh shifting, transmission overheating.
- Fixes: Check the fluid pressure sensor, wiring, and fluid levels.
7. P0888: TCM Power Relay Sense Circuit
This code signals that the TCM power relay is stuck in the off position or that there’s an issue with its circuit.
- Symptoms: CEL, limp mode, no power to the TCM.
- Fixes: Replace the power relay or repair the circuit.
8. P1745: Transmission Line Pressure Too High for Too Long
Excessive transmission line pressure can lead to harsh shifting or internal damage.
- Symptoms: Rough shifts, transmission overheating.
- Fixes: Inspect the pressure regulator, solenoids, and fluid condition.
Common Symptoms of TCM Issues
When your TCM encounters a problem, you may notice the following symptoms:
- Check Engine Light (CEL) or transmission warning light
- Limp Mode: Limited power with the transmission stuck in one gear
- Harsh or Delayed Shifting
- Transmission Overheating
- Slipping Gears
How to Diagnose and Fix TCM Fault Codes
- Scan for Fault Codes: Use an advanced OBD-II scanner capable of reading transmission-specific codes.
- Inspect Sensors and Solenoids: Check the input/output speed sensors, solenoids, and their wiring for damage or wear.
- Check Transmission Fluid: Ensure the fluid is at the correct level and free of contamination.
- Inspect TCM Connections: Verify that all TCM connectors and wiring harnesses are secure and free of corrosion.
- Update TCM Software: A firmware update may resolve certain issues, especially for recurring codes.
- Repair or Replace Faulty Components: Replace damaged sensors, solenoids, or the TCM as needed.
Preventing TCM Issues
- Regular Maintenance: Keep transmission fluid clean and at optimal levels.
- Prompt Repairs: Address minor issues before they escalate into major problems.
- Use Quality Parts: Opt for OEM or high-quality aftermarket components during repairs.
Final Thoughts
Understanding TCM fault codes is vital for maintaining your Dodge’s performance and longevity. By recognizing the symptoms and addressing them promptly, you can avoid costly repairs and ensure your vehicle remains reliable.
If you’re experiencing any of these fault codes or symptoms, don’t hesitate to consult a trusted mechanic or transmission specialist. For detailed information or help with your Dodge’s transmission, contact Auto Computer Performance for expert guidance.
