P0700 – Meaning, Causes, Symptoms, & Fixes
Code P0700 Definition
Transmission Control System Malfunction
Code P0700 Meaning
Many cars have a control module for the automatic transmission called the transmission control module (TCM). The TCM monitors the sensors and actuators relating to transmission control and communicates with the Engine Control Module (ECM) to inform it of any possible issues with the automatic transmission control module. The trouble code P0700 is set whenever the TCM detects a malfunction with the transmission controls.
- Check Engine Light
- Drivability issues
- Bad fuel economy
- Transmission shifting problems
- Fail safe mode
- Defective shift solenoids
- Defective engine coolant sensor
- Shorted or open circuit Transmission Control Module (TCM)
- Faulty Transmission Control Module (TCM)
Code P0700 Severity – Severe
The vehicle should avoid being driven when returning the trouble code P0700. It could get caught in one gear and cause not only a safety hazard for you but for those around you as well.
Code P0700 Common Diagnosis Mistakes
Diagnosing as an engine misfire or internal transmission problem before testing looking at freeze frame data.
Code P0700 Diagnosis Steps
- Tools Needed to Diagnose:
How To Diagnose P0700
- Check freeze frame data. Pay close attention to the engine load (torque), throttle position, RPM, and road speed by using your FIXD sensor and app’s freeze frame data
- Compare the RPM input speed and compare the RPM output speed on a flat, smooth surface.
- When comparing the torque converter RPM to the Input Shaft RPM keep an eye out for a Converter Slip Speed PID or Parameter Identification. To test this, gradually depress the throttle starting above 45mph. If it is function properly, the Slip Speed should never be above 50 RPM. If the Slip Speed increases when gradually depressing the throttle while above 45 mph, then you know you have a slipping Converter Clutch.
- If you are doing this test and the Slip Speed stays steady but the transmission Output Shaft Speed and MPH start to decrease, then you know that you have an internally slipping transmission (usually because of worn Clutch Packs or Sprag Clutches.
- Check transmission fluid to make sure that it is not dirty (should be red not black) and at a sufficient level. Replace if necessary.
- If these steps do not clear your Check Engine Light, you may need to visit a mechanic because there may be internal electrical issues.