[05 Methods] How to Fix Transmission Control System MIL Request

A transmission control system mil request is a warning that should not be ignored.

You will get the P0700 code on an OBD2 scanner when the Malfunction Indicator Lamp (MIL) request appears.

The code is related to the transmission control system and needs to be resolved immediately.

There’s a meaning behind every character in the P0700 error code.

“P” means that the issue concerns the powertrain of the vehicle, “0” means that the code applies to all types of cars, and “7” means that the problem involves the transmission.

That’s why the code P0700 is an indication of transmission control malfunction.

Some significant factors, including transmission fluid, transmission control module, valve body, electrical connections, etc., are responsible for this problem.

In this article, I have briefly discussed the causes and solutions for the P0700 code or transmission control system mil request.

What Does It Mean When It Says Transmission Control System MIL Request?

A Transmission Control MIL Request Warning means that the TCM detects something wrong with the transmission control system.

In this case, the OBD2 scanner generates P0700 codes, which means there is a severe issue with the transmission, and it is unsafe to drive.

MIL Request warning sign causes 06 symptoms:

  • Issues with gear shifting
  • Vehicle hesitation or vibration while changing gears
  • Rough driving
  • Stalling
  • Reduced fuel economy
  • Check engine light appears

How to Fix Transmission Control System Mil Request [05 Ways]

You can fix the transmission control MIL request by adding transmission fluid, repairing the damaged electrical connection, repairing the faulty valve body, and repairing the transmission module and solenoids.

Let’s get into more detail.

01. By Adding Automatic Transmission Fluid

By Adding Automatic Transmission Fluid

Low transmission fluid level is one of the most common reasons for P0700 and Transmission control system mil requests.

Make sure that the fluid quality is also checked.

If it is contaminated or bad, it’s time to change the transmission fluid.

The fluid level drops if there are leaks in the transmission system.

You should also check for leaks and fix them.

Transmission fluid costs between $100 and $250.

02. By Repairing the Damaged Electrical Connection

By Repairing the Damaged Electrical Connection

Check the connections between the power controller and valves in the transmission control system.

Use a multimeter and check the connectors.

Any connector that does not have power indicates a problem with the wire connecting it.

Replace the wire to solve the problem.

03. By Fixing the Faulty Transmission Valve Body

By Fixing the Faulty Transmission Valve Body

A damaged valve body triggers the MIL request and causes the P0700 code to appear.

Symptoms of a faulty transmission valve body:

  • Knocking or slamming noise
  • The vehicle slows down in reverse mode
  • Slips when shifting gears

A faulty valve body creates pressure on the transmission and causes the transmission control system MIL request.

You can hire an experienced mechanic to rebuild the faulty valve body.

Rebuilding is advisable because it is less expensive than buying a brand-new valve body.

Rebuilding a faulty transmission valve body costs between $320 and $950.

04. By Fixing the Transmission Solenoids

By Fixing the Transmission Solenoids

As a mechanic, I advise leaving this checking process to a qualified technician.

Because a transmission solenoid is an intricate part of a vehicle’s transmission, it requires special attention.

The transmission might worsen if you open it and don’t handle it right.

If there is any problem with the transmission solenoids, the mechanic will fix the problem or replace the solenoids.

Depending on the problem, it may cost around $67 to $490.

05. By Fixing the Transmission Control Module

By Fixing the Transmission Control Module

Sometimes a faulty TCM or Transmission Control Module causes the P0700 transmission control system MIL request.

You should check whether the transmission control module is faulty or not.

You can use an OBD-II scanner and scan the code to know whether it is faulty.

If you find the P0700 code, then you must check the TCM.

You will find the TCM under the cover back of the transmission case, near the ECM (Engine Control Module).

Inspect the TCM visually and all of its electrical connections.

If you find any problems or damages, replace the transmission control module.

Generally, replacing a TCM will cost around $700 to $900.

Follow these 07 steps to replace the TCM on your own.

  1. Disconnect the negative cable from the battery to avoid electrical shock.
  2. Pull out the wiring connectors from the transmission control module.
  3. Remove the nuts and bolts of the faulty TCM.
  4. Remove the faulty TCM.
  5. Install the brand-new TCM properly; make sure the new TCM is adjustable in your vehicle.
  6. Reassemble all parts properly.
  7. Now, reprogram the system according to the dealer level and reset codes.

Here’s a video showing you how to fix transmission control system MIL requests:

How Do I Fix Code P0700?

The P0700 code appears on the OBD-II scanner when you experience problems shifting gears, rough driving, or reduced fuel economy.

You must identify the faulty component causing the P0700 code before trying to resolve it.

Then repair or replace the faulty parts to fix the code P0700.

The following components need to be replaced or repaired to fix the P0700 error code:

  • Check transmission fluid level and quality; change the fluid if it is contaminated.
  • Check the wiring connectors and replace them if faulty.
  • Replace the defective transmission solenoids.
  • Check the TCM and replace it if the TCM is faulty.

How Much Would It Cost to Fix Code P0700?

The estimated cost of fixing the P700 error code depends on the problem type.

You should take your vehicle to a repair shop; they have advanced scanners that provide specific codes.

And you’ll know which faulty part is causing the P0700 code, and that’ll save you time and money.

Usually, if the problem is with a cable connector, it costs you around $60 to $200.

If the problem is with the transmission control module, the average cost of replacing it is between $700 and $900.

If the problem is with the transmission, the average repair cost is about $400 to $1,300, while the replacement cost is about $1,850 to $4,200.

On average, the cost is between $200 and $1200 to fix the P0700 code.

How Do You Clear a P0700?

The only way to clear a P0700 fault code is to replace the faulty parts that generate this code.

Note that transmission fluid level, quality, faulty transmission valve bodies, transmission control modules, solenoids, etc., are responsible for triggering the P0700 fault code.

If the faulty part is old enough, repairing it does not provide a long-term solution.

In this case, replacing is the most effective solution.

Final Thoughts

It is easy to fix the P0700 transmission control system mil request.

Most of the time, you can fix the P0700 code by yourself using the methods described here.

Since fixing the problem is quite expensive, you should drive your vehicle carefully to avoid the problem.

Schedule regular maintenance for the vehicle and change the transmission fluid on time to maintain a healthy transmission system.

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