Generic OBD2 code · Transmission

P0700: Transmission Control System (MIL Request)

The transmission control module (TCM) has detected a problem and asked the engine computer to turn on the check engine light.

CodeP0700
SystemTransmission
Typical urgencyModerate to high
Can I keep driving?Depends on how the car shifts. If it slips, shifts harshly or stays in one gear, limit driving and get it checked.

What does P0700 mean?

P0700 is an informational code. It does not name the fault. It tells you that the transmission control module has stored one or more codes of its own.

To find the real problem you need to read the codes stored in the transmission module. A generic OBD2 code read from the engine computer may only show P0700.

Common symptoms

  • Check engine light on
  • Shifting problems, such as harsh shifts or not shifting
  • Possible decrease in fuel economy

Common causes

The causes below are the ones commonly seen with P0700. The actual cause can vary by vehicle, engine and mileage, so treat this list as a starting point, not a diagnosis.

  • A fault detected by the transmission control module, such as a shift solenoid problem
  • Transmission fluid or hydraulic problems
  • Wiring or sensor faults reported by the transmission module

What to check with a scanner

  • Read all stored codes. If your scan tool or vehicle profile can access the transmission module, read its codes directly.
  • Check the transmission fluid level and condition if your vehicle has a dipstick and the manufacturer allows it.
  • Note when the problem happens: cold, hot, at certain speeds or gears.
  • Do not clear P0700 before recording the transmission codes.

How to read and clear P0700 with OBD Master Pro

  1. Plug in your adapter. Connect a generic ELM327 (or ELM329) OBD2 adapter to the diagnostic port, usually under the dashboard on the driver's side. Bluetooth Classic, Bluetooth LE, Wi-Fi and USB OTG adapters are supported.
  2. Switch the ignition on. Turn the key to ON or start the engine, depending on your car.
  3. Connect in OBD Master Pro. Open the app, go to Connection and pick your adapter. Classic Bluetooth adapters connect from the Bluetooth tab, Bluetooth LE adapters from the BLE tab with no pairing needed. Use the generic OBD2 / EOBD profile or your car's brand profile.
  4. Read the codes. Open the fault codes screen to see stored, pending and permanent codes. Confirm P0700 is listed and note any other codes, since they often explain the cause.
  5. Check the details. Look at freeze frame data, Live data and, where your car supports it, Mode 06 test results (see the checks above).
  6. Fix, then clear. After the repair, clear the codes to turn off the check engine light. Clearing also resets the emissions readiness monitors, so drive normally and check the readiness screen before any inspection. Permanent codes cannot be erased with a scan tool; they clear on their own once the car's self test passes.

Tip: you can also look up P0700 and other codes in the app's DTC search without connecting to a car. If your adapter will not connect, use Connection > Share connection log and email it to support. Many cheap ELM327 clones only handle basic engine OBD2, which is all you need for P0700.

When to see a mechanic

Get professional help if any of these apply:

  • The transmission slips, shifts harshly or stays in one gear
  • You cannot read the transmission module codes
  • The fluid is low, dark or smells burnt

If you are unsure, a qualified technician can confirm the cause with tests such as smoke testing, pressure testing or scope readings. Clearing a code does not repair the fault.

P0700 FAQ

What does P0700 actually mean?

It means the transmission computer has its own fault code stored. P0700 itself does not say which part failed.

Can I drive with P0700?

If the car shifts normally, drive gently until it is checked. If it slips or stays in one gear, limit driving to avoid further damage.

Why does my scanner only show P0700?

Generic OBD2 reads the engine computer. The detailed codes are stored in the transmission module and need a tool that can read that module.

Check P0700 on your own car

OBD Master Pro turns your Android phone and a generic ELM327 adapter into a code reader: read and clear codes, view freeze frame and live data, and check emissions readiness.

Get it on Google Play

Related guides

Check engine light on: what to do · How to read an OBD2 code (P, B, C, U) · Stored, pending and permanent codes and freeze frame · OBD2 readiness monitors explained · OBD2 glossary · OBD2 by car brand

Sources

Published . Updated . This guide is general information for generic SAE codes. Always follow the service information for your specific vehicle.