Why Do Check Engine Codes Sometimes Include An Engine "Bank?"
Your car's check engine light is a valuable diagnostic tool for investigating engine problems. Many auto parts stores and shops will read your codes for free, but the information might seem cryptic if you aren't a mechanic. Most trouble codes describe where the computer thinks your problem may be, but they don't always point at the genuine underlying cause.
If you have enough codes read, you may also notice that many of them report a problem with "bank 1" or "bank 2." What does this mean, and how can it help you get to the bottom of your car trouble? Keep reading to learn why this extra information may help you solve your automotive issues.
Understanding Engine Configurations
Modern cars typically come in three configurations: inline, h-type, and v-type. These names might sound a little intimidating at first, but the name tells you almost everything you need to know. Your engine consists of multiple combustion chambers known as cylinders, and the configuration tells you how your car's manufacturer chose to arrange these chambers.
An inline engine (also known as a "straight" engine) puts all the cylinders in a row. If you have a 4-cylinder engine, it's probably inline. You may see these engines abbreviated with an I, such as I-4. V-type engines arrange the cylinders in two slanted rows so that a V-6 would have two rows with three cylinders on each side.
H-type engines are somewhat more specialized and uncommon. Like v-type engines, this configuration places cylinders in opposite rows. However, an h-type (also known as a boxer or flat engine) doesn't use slanted rows. Instead, h-type engines use horizontally-opposed or "flat" cylinders.
Why Configuration Matters
You may have guessed that the "bank" in your check engine code refers to a row of cylinders in your engine. You have only one row if you have an inline engine, so check engine codes will always refer to bank 1. On the other hand, v-type and h-type engines have two rows, which means your code may reference either bank.
Many issues, such as misfires and lean codes, originate with a single-cylinder on your car. Unfortunately, your vehicle's computer cannot always determine which cylinder is to blame. However, the design of most engines means that the computer may be able to narrow the problem down to a single row of cylinders. This information provides a valuable starting point for further diagnosis.
While your mechanic will usually need to use more information than a check engine code alone to solve any particular problem, they still provide important clues. Narrowing potential issues down to a single bank of cylinders makes it much easier for experienced technicians to understand the underlying source of any automotive issue. Reach out to your local auto service shop to learn more.