Peake Tools and Diagnostics

Diagnostics Overview

When your car's computer detects a problem or fault, it will trigger a Check Engine/Service Engine Soon warning light to let you know it needs attention. A fault code is also generated by the computer to let you know what the problem is.

That functionality is not unique to BMWs. In fact, all cars sold in the US produced after 1996 were required to have a diagnostic system to let inspectors and service professionals track emissions related problems. This system is called OBDII (On Board Diagnostics, second Generation). Contained within this system is a set of parameters to be monitored, and the corresponding fault codes. These codes are generic, and any OBDII reader (like those used by auto parts stores) will read them.


Your BMW - and, in fact, ALL BMWs as old as 1987 have maintained their own, factory-programmed and BMW-specific diagnostic system. The parameters monitored by this system extend beyond emissions related faults, and their corresponding codes translate to EXACTLY what the factory wants the technicians to know. Of course, some of these codes will overlap with OBDII codes, but the factory codes generally produce a more accurate result, which could save you time and money tracking down vague problems.

In short, the Peake Tools are made specifically for YOUR car, OBDII tools are not.

How to use the Peake Tool

Very simply, the Peake tool connects to your car using one of two possible diagnostic ports. BMWs produced between '87 and '00 have a round, 20 pin connector under the hood. Cars '01 and newer share the connection to the factory diagnostic system with the OBDII system. This 16 pin connection is located under the dash, below the steering wheel.

DO NOT LET THIS CONFUSE YOU! Just because the Peake tool connects to the 16 pin port DOES NOT mean it is connecting to the OBDII system - it is not. The port is simply shared, thus eliminating the need for the factory to install the port in the engine bay.

Once connected, you will have the option of several functions - reading codes, erasing codes/clearing Check Engine Light, and resetting oil and service interval reminders. These functions are selected using just two buttons and following the included instructions, which are also printed on the tool itself.

After you've read the codes, write them down, and consult the included manual for the translation to the actual fault the car has detected.

Selecting the right Peake tool for your car(s)

As mentioned above, you will need to connect to one of two possible ports. Since all cars produced after 1996 have the 16 pin OBDII port under the dash, if your BMW was built between '96 and '00, you will likely have BOTH ports. If you do have both ports, you will need the tool that connects to the round, 20 pin connector in the engine bay. This is because it is the one that connects to the factory system.

If your car is '01 or newer, you will need the tool to connect to the 16 pin under-dash port.

There are a few model year '00 cars that will only have the under dash port. You'll need the tool that connects to that port. This is most important because other than this model year, you can easily select the proper tool based simply on your car's year.

For BMWs '87-'00, you would use the R5-FCXIII. For BMWs '01-'06, you would use the R5-FCXIII-16. The -16 indicates the under-dash port. Model Year '00 owners must check to see if the 20 pin round connector is under the hood prior to ordering.

If you own multiple BMWs that span across the date cut off, you can purchase the R5-FCXIII and add an adapter to connect to the 16 pin connector, effectively extending the useful range of the tool from '86-'06.


You may recall that the previous generation Peake Tools had some limitations, even within their effective date range. Some 330s, most non-US Spec, and all diesel cars were incompatible with the Peake tool.

The updated tool eliminated the vast majority of these compatibility issues. Now, virtually any BMW in the usable date range are compatible - including non-US Spec and diesels!

Airbag Codes

Peake also makes an SRS/Airbag fault code reader. The R5-SRS tools are airbag specific, meaning this is all they do. The FCX tools discussed above WILL NOT read airbag codes.

Selecting an airbag tool is very similar to selecting an engine code (FCX) tool.

'94-'00 BMWs will use the R5-SRS '00-'03 BMWs will use the R5-SRS-16.

Currently, there is not a tool for '04 and newer cars.

Some '00 323s have compatibility issues with this tool. These issues are random, and Peake is looking for a solution. Contact us before you buy this tool for your 323.

Peake tools WILL NOT work on any non-BMW.

What the Peake tools WON'T do

The Peake tools have their purpose - they are simple, hand-held, BMW Specific engine or airbag fault code readers/reset tools. They will NOT provide you with real-time data, programming capability, or individual sensor testing. They will NOT read systems outside the ECU (or airbag module), meaning they will NOT read ABS, DSC, Transmission, EML, or any other components.

What you get when you order

Your Peake tool purchase will include the tool, a code/instruction manual, and protective case. FCXIII-16 and SRS-16 tools include an integral cable to connect to the under-dash port. There is NO NEED to buy any additional adapters unless you WANT to be able to scan cars across the '87-'06 range.


The Peake tools come with a 90 Day factory warranty. The tools are very simple - no moving parts to break. As experience electronic products tells us, if something is going to malfunction, it will be from day one. Therefore, the 90 day warranty is MORE than sufficient in our opinion. Additionally, Peake offers technical support regarding operation of the tool. They are not equipped to answer questions about what the codes mean or how to fix them.

The warranty does not cover damage caused by abuse, misuse, or improper/forced connections.

Like Peake, we at Bimmertools are not setup to answer mechanical questions or offer much advice when it comes to actually repairing issues you find with your Peake tool.