$7E9 And $7E8 Engine Code | Common Fault Codes Meaning

Engine codes are very useful tools to help locate issues with the engine and then attempt to fix them. Though along with an OBD code reader you also need to know the meanings of the codes themselves to fully make use of them. What does the $7E8 engine code mean?

Alongside the $7E8 code, which is a very important engine code, we’ll also discuss the $7E9 code. Once you properly understand the codes, you’ll be able to do maintenance on your vehicle much better.

$7E9 And $7e8 Code Meaning

What $7E8 And $7E9 Codes Mean?

&7E8 and &7E9 aren’t exactly engine codes and are often termed as transmission codes. Now, The OBD2 scan tool has 10 different modes to help you with car problems. The $7 at the start represents mode 7. The E8 and E9 represent different modules or parts of the vehicle from where the codes are retrieved. 

E8 represents the engine control module while E9 represents the transmission control module. In short:

  • 7E8 means a request code from ECM.
  • 7E9 means a request from TCM.

After inputting the codes a request will be sent and you’ll get a submenu. The submenu will give you access to powertrain or fault codes that start with P.

These powertrain or check engine light trouble codes are the real indicators of what’s wrong with your engine or transmission module. As a result, being able to access this submenu through the use of transmission codes is extremely important to perform proper maintenance on your car. 

Common Fault Codes in $7E8 And $7E9

Common Fault Codes in $7E8 And $7E9

There is one thing to take note of. Fault codes can differ from vehicle to vehicle though usually there are some common ones. As a result, it is impossible to document all the check engine light trouble codes for vehicles in this article. So you should always try to look at instruction manuals for your particular vehicle to get the full list of fault codes.

Let’s start with some common fault codes for the air intake codes $7E8 and $7E9. First we’ll list error codes for code 7E8.

1. P0171

This code on the scan tool represents a malfunctioning oxygen sensor. While you can still drive your car you will find it difficult to control and experience reduced efficiency.

2. P0300

The error code represents engine misfire. When this occurs you will be unable to start your car.

3. P0401

If you see this code, it is usually indicative of a faulty EGR valve. This often leads to engine misfire and can damage your exhaust.

4. P0420

This is a particularly worrying code since it represents a bad catalytic converter. Bad catalytic converters can result in higher fuel consumption and black smoke from the exhaust.

Next, let’s look at some common fault codes for $7E9. If there’s an issue with transmission control, you may often experience slow acceleration. The common codes include:

1. P0218

When you see this code, you should know that the temperature of your transmission is going over safe values and can prove risky.

2. P0700

This code signals transmission control system malfunction.

3. P0715

The P0715 code represents speed sensor malfunction. It can make your car difficult to control.

4. P0729

This code indicates a problem with your gear ratio. If your gear ratio is messed up, your torque is heavily affected and your car will have reduced efficiency.

Additional Codes

There are a few more codes that aren’t as commonly seen but still deserve a mention. These are trouble code 7EB, 7EE, 7EC, 7EF, 7ED, 7EA code. They aren’t engine codes and are considered Controller Area Network identifiers. 

These codes are primarily used to identify faulty sections of the ECU. The engine control unit is quite large and finding malfunctions in it can be difficult and so these codes are used to simplify the amount of work needed.

What does P1326 Mean?

The P1326 trouble code indicates that there is an issue with the engine fuel and air metering throttle/pedal position sensor/switch A circuit. If you use a throttle enhancer, then you will need to give it a check.

It can also happen when the knock sensor has detected vibrations from the engine rod knock. That said, it’s possible for this code to be triggered untimely due to wrong knock sensor logic programming set up in the vehicle’s engine control module.


We hope that this article helped you understand what the $7E8 engine code does. Knowing about this code and other assortments of codes will help you take better care of your vehicle. 

Related Posts:

What is 7EA Engine Code? Explained By An Expert

7EB Engine Code: What Does it Mean?

P0015 Engine Code: A Definitive Guide to Meaning, Causes & Fixes

What Does Engine Light With Down Arrow Mean? Find Out Now!

Can A Weak Alternator Cause Poor Engine Performance? Learn Now