How to de-pin BMW Bosch 2, 3, 4, and 5 pin connectors

How to de-pin BMW Bosch 2, 3, 4, and 5 pin connectors

BMW used a lot of these Bosch style connectors on their cars during the 80s and 90s. Below are a 5-pin female and 2-pin male style. 

Unfortunately, they decided to permanently lock the connectors which prevents them from being de-pinned. Let me show you what I mean. 

Circled in red you can see where they heated up the connector and pressed down into the cavity where the wires are. This prevents the wire from being evacuated. Even if you have the correct de-pinning tool, the wire will get stuck and not back-out all they way. 

Here you can see where that little nub is.

 

The best fix for this is to replace the connector entirely. The connectors I sell are not locked. I also sell a de-pin tool that will work on the connectors I sell. 

Bosch style 2 pin connector 

Bosch style 3 pin connector 

De-pin Tool

Example Falk Manufacturing custom BMW M20-to-M50 TPS adapter harness

Need a custom BMW wiring harness?

Falk Manufacturing builds custom and small-run BMW adapter harnesses. The M20-to-M50 TPS adapter harness shown here is one example of a clean, reversible connector conversion that avoids cutting the original engine harness.

Have a different connector conversion or harness-repair project? Email info@falkmfg.com with the vehicle year and model, engine and ECU information, clear photos of both connector faces, and any available pinout information. I’ll review the project and do my best to develop a solution for you.

View the M20-to-M50 TPS harness example →

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3 comments

@Henry, if the connector was heat-staked down like the examples I show in red, the best thing to do is to cut the wires close to the connector and replace it with the 2 or 3 pin options I sell.

@Shane I have not been able to find the 5-pin version. If you really wanted to salvage the 5-pin you could try and drill-out the portion I show where they heat-stake it. Then the pins wont be permanently stuck and you can get them out with the de-pin tool I sell.
Depin tool: https://falkmfg.com/products/bosh-style-connector-de-pin-tool

Jacob Falk (Author, Owner)

When replacing connector you have to just cut off wires or how do i keep wires and remove connector ?

Henry

Can you provide the Bosch 5 pin connector and pins as used for the plug to the AFM on the E30 M3 as my wiring has broken close to the plug and I can’t get the wiring pins out of the plug. Thanks, Shane

Shane Mann

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