Engine Code p0700 Meaning, Causes, Fixes (5 Steps)

Is your vehicle currently plagued with a mysterious p0700 fault code?

If so, you are in the right place!

We have just the answers you are looking for, and can help you tackle your vehicle’s issue head-on.

In this PopularMechanic article you will learn:

  • What Does The p0700 Code Mean?
  • What Caused The p0700 code (Possible Symptoms)?
  • How To Diagnose An p0700 Code?

And Much More!

Engine Code p0700 Meaning, Causes, Fixes (5 Steps)

The sudden illumination of your vehicle’s check engine light never comes as a welcome sight. When this occurs, many vehicle owners fear the worse, and do not know where to turn.

This is where we come in.

We are all too familiar with diagnostic trouble code p0700, and have compiled all the necessary information to assist you in remedying your vehicle of what ails it.

The following guide will put you on the fast track toward repairing your vehicle, allowing you to get back on the road far sooner than you might have thought possible.

What Does The p0700 Code Mean?

DTC (diagnostic trouble code) p0700 designates a “transmission control system malfunction.”

When this error code is stored, a vehicle’s check engine light is illuminated.

All vehicles since 1996 come outfitted with an OBD2 (on-board diagnostics) system.

This system serves as a data link for all of your vehicle’s electrical signals. This system also allows for 2-way communication between various electronic vehicle control modules.

Modern vehicles have both a PCM (powertrain control module) and a TCM (transmission control module). 

These two modules communicate with one another to provide optimum synchronization between a vehicle’s engine and transmission.

This maximizes overall performance.

In the case of a p0700 trouble code, the TCM has stored a fault code of its own. The occurrence of a malfunction is then passed along to PCM, where it also stores a code.

This code serves as a warning to a vehicle’s driver that an issue has arisen, and further diagnostics are needed.

What Caused The p0700 code (Possible Symptoms)?

The root cause of a p0700 code stems directly from a transmission problem. The type or severity of this problem will require further examination to determine. 

Some of the most common causes of transmission codes include, but  are not limited to:

  • Low or dirty transmission fluid
  • Faulty speed sensors
  • Wiring harness issues, such as open circuits
  • Malfunctioning shift solenoid
  • Valve body irregularities
  • Converter clutch 

In rare cases, a faulty transmission control module can be to blame for a p0700 fault code. However, this is only the root cause in a very small percentage of cases.

The symptoms associated with a p0700 fault code can range drastically, based upon the type of malfunction experienced by the transmission. In some cases, no driveability concerns will be apparent.

In other cases, a hard shift/ no shift condition can be experienced. Other common symptoms include transmission slippage and poor gas mileage.

Read More >> What Are The Best Spark Plugs For Fuel Economy?

Did you know: Error code P0700 can be caused by excessive metal buildup in the transmission, however it could also be caused by metal flakes in the transmission fluid.

How To Diagnose An p0700 Code?

When your vehicle’s ECM (engine control module) has stored a p0700 fault code, further diagnoses will be required in order to determine the necessary course of action for repair.

The following steps can be used in order to successfully diagnose this issue.

  1. Check Transmission Codes
  2. Study Freeze Frame Data
  3. Inspect Wiring Harness/Sensors
  4. Consult Factory Service Literature

Step 1: Check Transmission Codes: 

To begin, you must determine what DTC(s) are stored within the TCM. This will be done with a quality OBD-II scan tool.

Not all scan tools are engineered to display TCM data, so compatibility should be determined. 

Step 2: Study Freeze Frame Data: 

You will also need to study any available freeze frame data associated with stored transmission fault codes.

This information will show when, and under what conditions, a fault has been detected. Data such as engine RPM/ input speed, gear range, and sensor values can all be determined. 

Step 3: Inspect Wiring Harness/ Sensors: 

You will now conduct a visual inspection of your vehicle’s wiring harness.

Look for any broken, rubbed, or pinched wires. 

Also check for any loose, disconnected, or dirty grounds.

Additionally, all externally located sensors should be checked for damage and poor connection.

Step 4: Consult Factory Service Literature: 

It will now be imperative to locate factory diagnostic service literature pertaining to the transmission code that has been set.

There are a wide range of automatic transmissions used in today’s vehicles, and all will be slightly different from one another.

This service literature will provide you with step by step directions (trouble-tree) for diagnosing the fault code that has been set, as it pertains to your exact transmission.

Read More >> What Does The P0420 Engine Code Mean?

How Do I Fix An p0700 Code?

  1. Fix Damaged Wiring
  2. Replace Damaged Sensors
  3. Test Drive Vehicle
  4. Make Designated Repairs
  5. Road Test Vehicle

Step 1: Fix Damaged Wiring

You will begin the repair process by fixing any visible wiring damage associated with the transmission wiring harness. Additionally, all grounds should be checked for integrity, and cleaned if necessary.

Step 2: Replace Damaged Sensors 

If any external sensor appears to be damaged, replacement will be necessary. Also, if pins within a sensor’s connector are bent or damaged, and cannot be repaired, the sensor should be replaced.

Step 3: Test Drive Vehicle 

After all visible damage has been repaired, clear the existing TCM fault, and road test your vehicle. Note whether or not this code is set once again.

Step 4: Make Designated Repairs

You will now continue with your diagnoses as specified by factory specific service literature. Be sure to carefully conduct all tests as specified, as a failure to do so is one of the most common mistakes in the diagnosis process. Replace any components that are determined to be faulty under these directions.

Step 5: Road Test Vehicle 

You will now once again test drive your vehicle to verify the completion of the repair process. If all concerns have been addressed, no fault-code should return.

Read More >> What Do You Do About The Service Engine Soon Light?

P0700 Repair Made Easy

In most cases, the diagnosis and repair of fault code p0700 is seldom as difficult as one might think.

The key to being successful in this regard is to take your time, and achieve an accurate diagnosis.

This saves time/money and prevents missteps along the way.

By following the directions provided above, your p0700 fault code will soon be a thing of the past, and your vehicle will be back on the road far quicker than you might have imagined possible.

About Your Mechanic

About Josh Boyd

I’ve been an ASE Certified automotive/heavy equipment technician since 2010. I began my career performing basic automotive maintenance at a service center before working as a Toyota technician at my local dealership.

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