How to Fix Transmission Control System Mil Request?

Your car can show a transmission mil request massage or P0700 error code on the display due to plenty of reasons. It includes low or dirty transmission fluid, a faulty solenoid, a bad coolant temperature sensor, or a damage valve body. It’s a bit risky to drive the vehicle with this warning light as it can cause the engine to stall, make it difficult to change gear, and operate the vehicle properly.

How to fix the transmission control system mil request problem? To disappear this error message, you have to run a scanner tool and check the transmission system physically and take steps accordingly.

What does a Transmission Control System Mil Request Mean?

The transmission control system mil request warning light indicates that there might be a problem with the transmission system that requesting the check engine light to be on. MIL refers to a malfunctioning indicator light.  

To understand the issue specifically, you’ll need to use an OBD2 scanner. In most cases, the scanner will generate a P0700 code. So the possible causes are fluctuations in fluid pressure or unexpected fluid pressure range. It can happen due to dirty filters, or polluted or worn-out fluid.

The transmission problem can also range from low transmission fluid to damage solenoids. A faulty control unit may also trigger this error message on your vehicle’s dashboard. If the scanner shows other codes along with P0700, there might be a problem with transmission solenoid speed sensors. So it’s better to bring the car to a licensed auto repair shop and solve all the possible issues to disappear the error code and light.

Causes of Transmission Control System Mil Request

According to the repairpal, repairsmith, and AutoZone, the transmission control system mil request warning light may come on due to several reasons that show certain symptoms. However, the causes and signs may vary depending on the car’s make and model.

Common causes of transmission control system mil request

  • Dirty or low transmission fluid
  • Faulty shift solenoids
  • Low engine cooling performance sensor
  • Defective valve body
  • Faulty wiring or TCM connector
  • Slipping converter clutch
  • Common symptoms of transmission control system mil request
  • Activate the check engine light
  • Transmission shifting problem
  • Poor fuel economy
  • Engine stalling

How to Fix a P0700 Transmission Control System Malfunction?

Since there are lots of potential sources that can trigger this error message, you should first run a scanner to clear all the codes and then inspect the vehicle physically.

How to Fix a P0700 Transmission Control System Malfunction

1. Scan the Codes

Hook up an OBD II scanner device to your vehicle and check the existing codes. The P0700 shouldn’t come alone.

To determine the reason that triggers the check engine light and the particular error message, check the freeze frame data of all codes. Then refresh the codes and test drives the car and monitors the transmission information on the scanner.

2. Check the Transmission Fluid

If your OBD scanner only detects the P0700 code, the first thing you should check is the transmission fluid. Check the fluid level and make sure it’s full on the stick. The transmission fluid should also be dark red or pink.

Check the Transmission Fluid

If the fluid looks like a black, gritty, strawberry milkshake or smells burnt, the fluid is cross-contaminated with coolant and needs to be changed. Since all transmission fluids aren’t the same, be careful about the correct type.

3. Check the TCM

The P0700 also refers to TCM (Transmission Control Module). If the TCM is affected, gear changing can be difficult. It’ll also affect the fuel economy. In this case, change the filter and oil. Then clean the TCM’s electrical connection.

Check the TCM

Check the wiring harness for missing ground or broken wiring. If the P0700 code still comes back, the TCM any get damaged and need to be changed.

4. Faulty Wiring

Check the wires that go to the sensors under the air intake and battery box as they may break inside the insulation. If so, locate the place from where you can see the TCM connector.

Remove the tape from the sensor connector and pull each wire separately and there may be one purple wire and one orange. Determine the broken copper wire and replace it with a new one and the problem should be solved.

5. Failing Shift Solenoid

If the transmission solenoids fail, you will experience irregular gear shifts. The car’s gear may suddenly jump to another gear even when you are driving at a certain speed.

Failing Shift Solenoid

If so, you may have to change the transmission solenoid. However, you can first clean the solenoid before trying to replace it. Possibly old fluid can stuck on it and cause the malfunction.

6. Bad Transmission Valve Body

The sign of a faulty valve body includes hearing a knocking or slamming noise during applying pressure to the brakes. The vehicle may also slow down while in reverse mode and the shifting stick may slips continuously while changing the gears.

Bad Transmission Valve Body

It can end up damaging the whole gearbox. A faulty valve body also put excessive pressure on the transmission. To fix this problem you’ll have to replace the valve body.

Cost of Fixing Transmission Control System Mil Request

The cost of fixing this error massage varies depending on the root of the problem that the mechanic will determine by diagnosing. The mechanic may first change the transmission fluid which will cost around $80 to $250 while flushing transmission fluid costs between $165 and $290.

Cost of Fixing Transmission Control System Mil Request

The mechanic may also replace the connectors and all wires between the TCM, PCM, and ECM and repair the TCM. While repairing the TCM cost around $300, replacing this system can cost up to $900.

It may also cost around $150 to $400 to replace the shift solenoid to fix the transmission control system mil request problem. If all these attempts fail, the mechanic will change the transmission and it’ll cost around $2300 to $4400.

Can you drive with the Transmission Control System Mil Request?

When your car shows transmission control system mil request massage, it can causes drivability issues and serious transmission problems can be the reason. So you should stop driving immediately.

An activated P0700 code can also cause transmission shifting issue and stuck the vehicle in 4th gear even when its need to be in 2nd gear. This can endanger both driver and passenger. Driving the vehicle in this condition can lead to severe injury and cause worse damage to the car.

But if you don’t have any choice, drive the car slowly and reach a service center or home garage. If your vehicle has a failsafe mode like some modern cars, activate it to limit the car’s engine performance to avoid the majority of safety-related failures. However, the failsafe mode can make it impractical to operate the vehicle.

FAQs

Can you fix the transmission problem without removing it?

Yes, you can fix the transmission problem don’t require to remove it unless its housing is cracked. You can replace its solenoid, speed sensor, gear shift indicator, filter, and other parts without removing the transmission. You can also replace the linkage and shifter of the manual transmission without removing it.

How to avoid the P0700 error code in the future?

Maintain your car’s transmission system properly to avoid the P0700 code. Inspect the transmission fluid and refill or replace it if needed. If you notice puddles or drips of transmission in the driveway or garage, determine and solve the transmission leak immediately.

How do I reset my TCM?

Can you fix the transmission problem without removing it?
Yes, you can fix the transmission problem don’t require to remove it unless its housing is cracked. You can replace its solenoid, speed sensor, gear shift indicator, filter, and other parts without removing the transmission. You can also replace the linkage and shifter of the manual transmission without removing it.

How to avoid the P0700 error code in the future?

Maintain your car’s transmission system properly to avoid the P0700 code. Inspect the transmission fluid and refill or replace it if needed. If you notice puddles or drips of transmission in the driveway or garage, determine and solve the transmission leak immediately.

Final Words

Whenever you notice a transmission control system mil requires an error message on your car’s display, don’t get panic. Park the car in a safe place and check its transmission fluid. If it’s okay, consult with a mechanic or carefully take the car to the nearest service center.

While keeping driving with this error message is risky and may cost expensive repair, inspecting the transmission regularly can help avoid triggering this error message or P0700 code.

My name is Tom Vanderbilt. I am an automotive expert and renowned for my profound knowledge of automobiles. I have made significant contributions to the industry through my experience and expertise. I have a natural curiosity and fascination for cars. My journey is to explore the intricate dynamics between people, their vehicles, and the ever-evolving transportation landscape.

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