DTC P0700 – What It Means, Causes, Symptoms, and Fixes

When it comes to how technological advancements may influence a particular industry, there can be a lot to discuss. These developments are primarily intended to aid in the resolution of some challenging problems we face every day. The automobile industry is one of the ones that has been seriously affected.

Deciphering auto issues has become incredibly simple since the OBD2 scanner was introduced. You can get the Diagnostic Trouble Codes for your car by simply using an OBD2 scanner. But do you understand what each diagnostic code points to? In this article, we’ll talk about the diagnostic P0700 code.

Vehicles frequently experience mechanical issues that can be linked to aging. But given the numerous parts and systems that contribute to your car’s overall performance, can you imagine how challenging it can be to identify the true issue?

Given the number of parts in a vehicle, it can be difficult to pinpoint some of these deep-seated mechanical issues.

But to find the source of a problem, we can’t just tear everything apart. The diagnostic codes are useful in this situation. Every diagnostic code corresponds to a specific mechanical problem. In any case, retrieving these codes with an OBD2 scanner is all you need to do if your car is having issues.

Depending on the component represented by the trouble code, this will help you locate the issue and then resolve it. As a result, finding the cause of a vehicle’s malfunction doesn’t require disassembling all of the components, making vehicle repairs easier in some ways.

What Is the Meaning of the P0700 Code?

A faulty Transmission Control System is indicated by the diagnostic trouble code (DTC) P00700 (TCS). Other names for it include the Transmission Control Module (TCM). The check engine lights will come on if the transmission control system isn’t working properly. This will inform you of the issue.

1. The Transmission Control Module
The Transmission Control Module by Mgiardina09 / CC BY-SA 3.0. The diagnostic trouble code (DTC) P00700 indicates that the Transmission Control System is malfunctioning (TCS). It also goes by the term Transmission Control Module (TCM). Incorrect operation of the transmission control system will cause the check engine lights to illuminate. This will educate you on the problem.

Additionally, your vehicle will enter failsafe mode to stop the engine from suffering any more harm. By using the OBD2 scanner to check your car, you can find this specific issue. This issue is indicated by the scanner displaying the diagnostic trouble code P0700. You should have it fixed as soon as possible to stop your engine from suffering additional damage.

A transmission control module is a common feature of contemporary vehicles. TCM is the usual abbreviation for this module. This module in a car plays many functions, one of which is to identify and report any faults in an automatic transmission vehicle. It then establishes a particular code and transmits it to the engine control module (ECM).

A malfunctioning vehicle component will then be indicated by the ECM. The TCM and ECM are always in constant contact. OBD2 code P0700 appears when both modules identify a problem with the transmission.

What are the Causes of the P0700 Error Code Appearing In a Car?

Circuit boards and microprocessors are assembled into a transmission control module. To engage a clutch, lock, or unlock a planetary gear set, it is in charge of activating solenoids, which in turn direct the flow of pressurized hydraulic fluid (transmission fluid) down the right channel.

Determine some of the potential causes of this malfunction before you attempt to repair any issue with the Transmission Control Module. This can prevent you from accidentally fixing the wrong components. Failure is always possible for many reasons, including:

1. A Malfunctioning Transmission Control Module

Other transmission parts, such as the sensors and actuators, are subject to monitoring by the transmission control module. To make sure the transmission operates properly, the TCM keeps an eye on its performance. The TCM may display errors when nothing is wrong if it develops a fault.

2. A Malfunctioning Transmission Valve Body

The transmission works by transferring fluids to various engine components, which aid in gear shifting and acceleration. The nerve center of the transmission is the valve body.

The valves ensure that the appropriate volume of fluid is delivered where it is needed. Any issue with these valves could result in a malfunction inside the transmission, which would produce an error code.

3. Issue with Shift Solenoids

The hydraulic fluid flow inside the transmission is regulated with the aid of the shift solenoids. It is the one that makes it simple for you to change gears as needed. The distribution of fluid can become problematic when shift solenoids malfunction. This may eventually cause the transmission to fail.

4. Wire Harness with an Open or Short End

The transmission and all of its sensors in modern cars are powered by several electrical systems. Transmission problems can result from electrical issues brought on by wiring short or an open connection.

2. OnBoard Diagnostics OBD handheld scanner 1
Since the OBD2 scanner was developed, identifying vehicle problems has become relatively straightforward. All you need is an OBD2 scanner to obtain your vehicle’s diagnostic trouble codes. Do you know what each diagnostic code means, though? We’ll discuss the diagnostic P0700 code in this post.

The TCM or PCM won’t be able to receive signals about what is happening with the tranny if the wiring is corroded, damaged, or shorted. The system will interpret events incorrectly and display the P0700 error code. On Mercedes and other car models, this error code P0700 may likely be accompanied by other transmission-related error codes.

5.  Low or Dirty Transmission Fluid

Transmissions are built by automakers to function best with sufficient and hygienic fluid levels. Similar to the engine, a low transmission fluid level will prevent the fluid from reaching every nook and cranny of the internal transmission parts. As a result, low or contaminated transmission fluid will cause the transmission to overheat, which will result in excessive friction and metal shavings.

What are the Common Symptoms Associated with the P0700 Error Code?

The TCM is failing in many ways. It is best to have it checked by a professional if you notice any of these so that transmission damage can be avoided. The cost of replacing or repairing the transmission can be high.

1.  Excess Accumulation of Heat In the Transmission

There are many causes for transmission overheating, including a faulty TCM. The transmission becomes stuck in a lower gear when pulling heavy loads or accelerating quickly to higher speeds.

When a transmission overheats, the parts and the fluid become less effective, which could lead to additional issues. Have a qualified transmission technician inspect the TCM and change the transmission fluid.

2. The Shift Locks In the Same Gear

When the transmission remains in the same gear and refuses to shift up or down as the engine speed changes, the TCM is most likely malfunctioning. For instance, the high torque needed to accelerate from a stop may prevent you from doing so if the transmission is stuck in high gear.

Even with the engine revving at a high RPM, the transmission stuck in first gear will limit the top speed you can travel. As the car slows down, the transmission ought to downshift.

3.  The Gear Is Locked In Neutral

When the transmission is stuck in neutral, that is another sign of a broken TCM. The transmission is stuck in neutral, so no matter which position the gear shift is in, the vehicle will not move.

In this circumstance, your car cannot be driven and needs to be fixed. Car owners will need to make arrangements for the transportation of their vehicles to a shop for potential transmission repairs and TCM module replacement.

4.  Not Able to Accurately Shift Into Higher Gears

As the speed of your car gradually rises, the TCM changes gears. The transmission should change to the next gear as soon as the top speed of each gear is reached.

When the shift doesn’t happen, your engine keeps turning at a high RPM without increasing your ground speed in tandem. Under these circumstances, your vehicle might not allow you to travel at highway speeds, which could be hazardous for both you and other high-speed traffic.

3. The internal components of an automatic transmission
The internal components of an automatic transmission by Silverxxx / CC BY-SA 3.0. The transmission control module is responsible for monitoring other components of the transmission, such as the sensors and actuators. The TCM monitors the transmission’s performance to ensure optimal operation. If the TCM develops a flaw, errors may appear even when nothing is wrong.

5. Downshifting Is a Problem for Gear Shift

As the ground speed gradually decreases, the TCM (Transmission Control Module) is also in charge of downshifting the transmission. The TCM ought to have put the transmission into first gear once you come to a stop at a stop sign or stoplight.

You should be able to accelerate the transmission. It may still be in a higher heart if the downshift does not occur, making it extremely challenging to accelerate from a stop. In some circumstances, the car may not be able to move at all from a stationary position due to the high gear position.

6. Prolonged Shifting

The TCM and transmission in your car are built to change gears only within a certain range of engine RPM and ground speed. The car loses momentum and may even slow down during a gear change if the transmission shifts gears slowly.

The effect will be even worse if delayed shifting happens while going up a hill. A poor TCM can make the gears shift slowly and have a significant impact on the vehicle’s performance.

7.  Very Bad Fuel Economy

To deliver maximum power at maximum fuel efficiency, the TCM, transmission, and engine are all designed to work together. The fuel economy may suffer whenever the TCM is operating improperly.

For instance, an engine has to work harder and less effectively when the transmission shifts too late or not at all. Most of the time, more fuel is used, which reduces the typical miles per gallon your car gets.

8. The Check Engine Light Turns On

There are numerous reasons why the check engine light may be on, so drivers should have their cars inspected by a licensed mechanic. If the check engine light is on and some of the aforementioned symptoms are present in your transmission, there is frequently a problem with the TCM module.

A mechanic may use a scan tool to look through the diagnostic trouble codes in search of a clue as to what is wrong. Typically, a P0700 error code denotes a TCU issue (Transmission Control Unit).

9.  Lack of Enough Transmission Fluid

Erratic shifting may be brought on by low transmission fluid. Increases in RPM during shifts, grinding noises, shifting that is erratic, and slipping in and out of gear are all symptoms. These signs may indicate that the transmission fluid is low.

Look under your car for telltale indications of fluid leaks. Due to the transmission having to work harder with less fluid, you might also notice it overheating by smelling burning. To prevent serious harm to the internal transmission components, always stop.

10. Slipping Transmission Gear

When your transmission shifts gears while you’re moving quickly, the transmission might revert to the lower gear, which is an indication of transmission or gear slippage. Possible causes include low transmission oil or a broken transmission control module.

Avoid operating the vehicle over long distances, while hauling heavy loads, or up inclines. Slipping gears could prevent acceleration to highway speeds, creating a hazardous situation on the highway with other high-speed traffic. Internal transmission parts might also be harmed.

4. The check engine dash warning light
The check engine dash warning light by Wikiuser100000 / CC BY-SA 3.0. The check engine light might be on for a variety of reasons, so drivers should get their vehicles evaluated by a qualified mechanic. There is commonly an issue with the TCM module if the check engine light is on and some of the aforementioned symptoms are present in your gearbox.

11. Stalling or Poorly Running Engine

A seamless driving experience is made possible by the cooperative efforts of the car’s engine and transmission. Most drivers and car owners attribute their vehicle’s transformation into a highway beast entirely to the engine. However, they were unaware of the transmission’s equal significance to the engine.

Therefore, the engine will stall or run poorly, especially on the highway, when a transmission malfunctions and the powertrain control module or the transmission control module stores the P0700 on a Duramax or any car model.

Diagnosing Code P0700

The next step is always to try to determine the most likely cause when you start to notice some of the symptoms that point out to failure within your transmission control system. While a skilled mechanic can fix the issue, you might want to attempt to locate and resolve the issue yourself. Here are the steps you can take if this is the route you would prefer to take and you feel very confident in your abilities:

Step 1: Use an OBD2 Scanner

Get your OBD2 scanner first so you can determine whether the issue is related to the transmission. It does not necessarily mean that your transmission is broken just because your car is having shifting and stalling issues.

You’ll need to use the OBD2 scanner to verify this. If you can locate the diagnostic trouble code P0700, a transmission-related issue is unquestionably present. Additionally, keep in mind that they might occasionally draw attention to issues with the engines as well. It will be the start of some serious work if this is the case.

Step 2: Erase the Code and Drive the Car for Tests

You must make sure the code wasn’t an accident before you start disassembling your engine or transmission. To ensure that the code is correctly identifying a real issue, you might want to take one more step.

After erasing the code, you can take a short drive in your car. Use your OBD2 scanner once more to verify if the code reappears if the check engine lights come on once more. If the P0700 error code returns, a transmission issue is almost certain to be the cause.

Step 3: Examine the Transmission

Checking for any obvious transmission damage is the first and simplest step to take. This entails checking the shift solenoids and the valve body. To ensure that all the electrical connections are in excellent condition, you must also inspect the electrical wiring. This is because incorrect wiring may also result in transmission failure, which will turn on the check engine light and result in the P0700 error code when scanned.

Step 4: Use the Live Scan Options

If your visual examination turns up nothing, you must proceed to the next phase. To see what might be happening inside the transmission, you must use the live scan device application.

If the source of the issue is found to be inside the transmission, fixing it will be a difficult task that should only be attempted by a qualified mechanic. You can determine whether there is a mechanical issue or an electrical issue with sensor failure using the live scan feature.

5. A typical car engine with six cylinders
A typical car engine with six cylinders by Kether83 / CC BY 2.5. The transmission and engine of the automobile work together to provide a smooth driving experience. The majority of motorists and automobile owners believe that their engine alone is responsible for turning their car into a highway beast. They were not aware that the gearbox was as important as the engine.

Common Errors Done In P0700 Code Fixing

The most frequent error when diagnosing the symptoms of a P0700 code is to believe that the issue is a transmission-related mechanical one. Transmission replacements are very pricey, as is well known. This means that any incorrect diagnosis will not only fail to treat the issue, but you will also have wasted a lot of money on pointless work.

Get that OBD2 scanner, read those codes, and look for a diagnostic trouble code P0700 or any other codes connected to a faulty transmission control module if you have any inkling that your transmission control module is the cause of the issue. Within a very short period, a TCM issue can be easily resolved.

Failure to thoroughly inspect the wire harness is another frequent blunder. If you think replacing a perfectly good TCM will solve the issue, you risk leaving the wire harness problem unresolved.

P0700 Code: How Serious Is It?

Transmission-related problems should always be handled with the utmost urgency. This is due to the ease with which a minor issue can develop into a larger issue that may result in the complete failure of the engine and transmission. The expense of rebuilding or replacing an engine and transmission can be unfathomable.

The car will simply function normally if the issue is just a faulty sensor. However, if the issue is coming from inside the transmission itself, you should just fix it right away because it could endanger your car’s performance in general.

When you start having trouble shifting, transmission failure poses the greatest risk. Serious mechanical issues may arise if the transmission fluid isn’t flowing smoothly to all of the transmission’s components.

P0700 Code: How Do I Fix It?

There are numerous steps you must take to troubleshoot the error if the diagnostic trouble P0700 code appears. These actions comprise:

  • Compare the RPM output speed and the RPM input speed using a Scan Tool on a flat, smooth surface.
  • Keep an eye out for a Converter Slip Speed PID or Parameter Identification when comparing the RPM of the torque converter to the RPM of the input shaft. Depress the throttle gradually, beginning above 45 mph, to test this. The Slip Speed should never exceed 50 RPM if everything is working properly. If the Slip Speed increases when the throttle is gradually depressed while traveling at speeds greater than 45 mph, the converter clutch is slipping. When performing this test, if the Slip Speed remains constant but the transmission Output Shaft Speed and MPH begin to drop, your transmission is internally slipping (usually because of worn Clutch Packs or Sprag Clutches.)
  • Make sure the transmission fluid is clean (it should be red, not black) and that there is enough of it. Replace as required.
  • You might need to see a mechanic if following these instructions does not turn off your Check Engine Light because there might be internal electrical problems.

How Much Does Fixing Error Code P0700 Cost?

The typical cost of repairing a transmission control module (TCM) is $300. This is a little less than the price of replacement. If it is not damaged, the TCM (Transmission Control Module) may only need to be reset in this situation.

6. The shift solenoid valves
The shift solenoid valves by Hammelmann / CC BY-SA 3.0. P0700 often results in shift solenoid codes. This might be as simple as low fluid due to a transmission leak or, at the other end of the spectrum, a transmission breakdown. When a transmission is deteriorating, metal flakes are frequently seen in the fluid. These flakes block solenoids and valve bodies, which might result in the P0700 error code.

A broken TCM needs to be replaced. Try it; it’s worth it. You might be able to cut your transmission repair costs significantly. The most important auto repair is a transmission or engine replacement.

But occasionally, the TCM might be broken and require replacement. Depending on the car model and labor costs, the replacement cost ranges from $250 to $1250.

The transmission control module typically costs between $200 and $750. The kind of parts that will be used will have a big impact on this. Compared to OEM parts, aftermarket components can be significantly less expensive. The price of the labor could be between $50 and $500.

Your particular vehicle’s design and type, brand, and the parts that need to be changed are just a few of the variables that affect the price of repairing or replacing the transmission control module in your car.

The transmission control module may even be installed inside the transmission in some cars. The issue that results from this is that you have to disassemble it, which can be very expensive.

Another thing to remember is that a diagnostic tool must be used to program the replacement transmission control module. The majority of the time, a workshop is required for this; even someone with basic knowledge cannot do it on their own.

Additional Comments Relating to the P0700 Code for Consideration

Shift solenoid codes are frequently seen with P0700. This could be something as straightforward as low fluid from a transmission leak, or on the other extreme, a transmission failure.

Metal flakes in the fluid are common when a transmission is failing. These flakes clog valve bodies and shift solenoids, which can cause the P0700 error code to appear.

Excessive metal buildup in the transmission is a sign that it needs to be rebuilt or replaced because it is a result of mechanical wear.

Can I Still Drive Even with the P0700 Error Code Symptoms?

You should stop driving right away because the P0700 error code may be a sign of serious transmission problems in the future or drivability issues today.

Shifting issues with the transmission can occur while driving with the P0700 code active. When you should be in second gear, you don’t want to be stuck in fourth. Additionally, you run the risk of further harming your transmission system.

The Conclusion

Throughout your car’s life, the TCM is probably not something you’ll ever need to replace or fix. However, your TCM, like any other part of your car, may occasionally fail and set off the P0700 code. It’s crucial to get in touch with a qualified mechanic right away for a P0700 code diagnosis in the event of a malfunctioning TCM. This is because ignoring it could result in more expensive issues.

A crucial part of any road-going vehicle with an automatic transmission system is the transmission control module. A TCM unit is standard in the majority of contemporary cars, which is convenient compared to relying on mechanical or hydraulic control.

Similar systems are used solely for clutch automation and actuation in conjunction with a variety of semi-automatic transmissions. A TCU in a contemporary automatic transmission typically uses information from the engine control unit (ECU) and sensors from the vehicle to determine how and when to change gears in the vehicle for the best performance, fuel efficiency, and shift quality.

7. P0700 8. P0700
The Transmission Control Module by Mgiardina09 / CC BY-SA 3.0