FCA Group SGW Bypass Adapter 12 + 8 PIN – Installation Guide (step by step)

FCA Group SGW Bypass Adapter 12 + 8 PIN – Installation Guide (Step by Step)

Last updated: January 12, 2026

This guide shows you exactly how to connect an FCA/Jeep/Fiat/Alfa/Chrysler/Dodge/Ram SGW Bypass Adapter (12+8 pin). The goal is for you to be able to use your diagnostic equipment to read/write to more control units than just the engine – on vehicles where the SGW (Security Gateway) otherwise prevents "unauthorized" OBD communication.

Important: Use SGW bypass on your own car and for diagnosis/service. Follow local regulations, manufacturer's terms, and be careful – incorrect connection can cause fault codes or, in the worst case, damage connectors.

Contents

• What is SGW and why does it exist?
• When do you need an SGW Bypass 12+8 pin?
• What you need
• Safety & preparations
• Step-by-step: Connecting the SGW Bypass (12+8 pin)
• After connecting: test that everything works
• How to disconnect and restore original
• Common problems & solutions (troubleshooting)
• Compatibility (quick list) + common variants
• Tips that save time (and nerves)
• FAQ – frequently asked questions (SEO)

What is SGW and why does it exist?

SGW stands for Security Gateway and is a "security port" in the car that controls communication between the OBD socket and the car's internal network (CAN/LIN, etc.). On many FCA/Stellantis vehicles (especially newer model years), often only basic OBD functions are allowed without extra authorization – for example:

• Reading/deleting engine-related fault codes may work.
• Advanced functions (ABS/SRS/BCM, service reset, coding, activation tests, adaptations) may be blocked.
• Diagnostic software may show messages such as "Security Access Denied", "Gateway blocked" or that control units are not found.

An SGW Bypass Adapter connects past the SGW module via its internal connectors (12-pin + 8-pin) and provides your diagnostic equipment with a direct path to the network – which is often needed for serious troubleshooting and service.

When do you need an SGW Bypass 12+8 pin?

You usually need a 12+8-pin bypass if:

• Your diagnostics work for engine-OBD but not ABS, airbag, body modules, service functions or live data in more modules.
• The software indicates that the vehicle has an SGW lock or that you lack authorization.
• You want to perform service actions (e.g. EPB/electric parking brake, calibrations, component tests) that are blocked by the SGW.

The alternative in some markets is to use authorized access (e.g. approved gateway access via vendor services), but bypass is the practical solution when working physically on the car.

What you need

• FCA Group SGW Bypass Adapter 12+8 pin (the correct variant for your car's SGW connectors).
• Diagnostic interface: OBD2 scanner / J2534 / brand-specific diagnostics (choose what supports your car and the functions you want to access).
• Software/app that can communicate with the relevant control units.
• Panel tools: plastic tools/trim tools + often Torx (T20/T25 are common), a small ratchet may help.
• Flashlight and preferably gloves (and patience).

Tip: On Felkodslasare.se you can quickly find related items via search: SGW bypass · J2534 · OBD2

Safety & preparations

• Ignition OFF. Remove the key/keep the remote at a distance (reduces the risk of modules waking up).
• Wait 2–5 minutes for the car to "go to sleep" before unplugging connectors (reduces fault codes and electronic complaints).
• Work calmly – do not pull cables, hold the connector body.
• If you are unsure or working near airbags/pyrotechnics: consider disconnecting the negative battery terminal. (However, this can cause some memory/clock resets and sometimes fault codes that need to be cleared afterwards.)
• Avoid static electricity (ESD) – touch the body/metal before handling control units.
• Do not leave the bypass connected permanently unless you have a clear reason. It is recommended to restore the original setup after diagnosis.

Step-by-step: Connecting the FCA SGW Bypass Adapter (12+8 pin)

1) Locate the SGW module

The SGW is often located in the passenger compartment near the OBD socket/under the dashboard, sometimes behind a panel in the knee area, or in some cases behind the glove compartment/center console. It can be a small black/grey box with two connectors: one 12-pin (larger) and one 8-pin (smaller).

• Follow the wiring from the OBD socket behind the panel – the SGW is usually "nearby".
• Look for markings that may include "Gateway", "SGW" or an FCA/supplier label.

2) Remove the panel to access (without damaging clips)

1. Use plastic tools and carefully loosen the panel.
2. Unscrew any Torx screws (put them in a cup so they don't get lost).
3. Create clear access to the SGW and connectors so you can see latches/clips properly.

3) Disconnect the car's original connectors from the SGW

1. Identify the 12-pin and 8-pin on the SGW.
2. Press the connector's latch/clip and pull straight out. Wiggle minimally – and never pull the cable.
3. Check that no pins are bent and that seals appear intact.

4) Connect the bypass harness "inline" (12+8 pin)

A typical 12+8-pin bypass consists of two pairs of connectors (one female + one male per size) and an additional OBD port/connection that you use for your diagnostics.

1. Match size: 12-pin to 12-pin and 8-pin to 8-pin (they are normally keyed, but never force them).
2. Connect the car's wiring harness (the connectors you just removed from the SGW) into the bypass's corresponding female connectors.
3. Connect the bypass's male connectors into the SGW module where the original was.
4. Push until it clicks. Double-check that the latch is locked.

5) Connect the diagnostic equipment to the bypass's OBD connection

1. On the bypass harness, there is usually an OBD2 female (16-pin). This is where you connect your scanner/interface.
2. Important: When the bypass is connected, you should generally not use the car's regular OBD socket for diagnostics – use the bypass port.
3. Ensure the cable is not pinched when you temporarily reattach panels.

6) Turn on ignition and run diagnostics

1. Turn on the ignition (engine usually does not need to be started).
2. Open your diagnostic software and select the correct car/model/year.
3. Try connecting to a "locked" module (e.g., ABS/BCM/SRS) and read fault codes/live data.

After connecting: test that everything works

A quick check that usually reveals immediately if the bypass is doing its job:

• Read module list (scan/all systems). Do you see more modules than before?
• Test ABS: read fault codes and live data (wheel speeds if supported).
• Test BCM/Body: read fault codes, check door/light status if the software supports it.
• Clear a test fault code (if you have an existing code you want to clear anyway) – confirm that it disappears and does not immediately return.

If you still get "Security/Gateway blocked" after bypass, it is often due to incorrect connection, wrong bypass variant, or your diagnostic system lacking support for that particular module/function (see troubleshooting).

How to disconnect and restore original

1. End the diagnosis and close the software.
2. Ignition OFF, wait 1–2 minutes.
3. Disconnect diagnostics from the bypass's OBD port.
4. Disconnect the bypass's 12-pin and 8-pin from the SGW.
5. Reconnect the car's original connectors directly into the SGW (12 to 12, 8 to 8) until it clicks.
6. Reinstall panels and screws.

Tip: If the car logs fault codes during the work (e.g., "communication error"), it is often harmless and can be cleared afterwards.

Common problems & solutions (troubleshooting)

Compatibility (quick list) + common variants

"FCA Group" often refers to vehicles within FCA/Stellantis, e.g., Jeep, Fiat, Alfa Romeo, Chrysler, Dodge, Ram and related brands. SGW is particularly common on many newer model years, but the exact presence depends on the market and model.

• 12+8 pin means that the SGW module uses two internal connectors: a 12-pin and an 8-pin.
• There are other SGW bypass variants (other connector combinations) – make sure you have the correct one for your specific SGW.

If you are unsure: visually check the SGW connectors before ordering/connecting, or use the search on the page: FCA SGW 12+8

Tips that save time (and nerves)

• Take a photo before you disconnect – that way you know exactly how everything was seated.
• Work with the car "sleeping" (wait a few minutes). Less risk of unnecessary communication codes.
• Never force connectors. If it doesn't go in easily, something is wrong (latch, angle, wrong connector).
• Short diagnostic sessions are often more stable than leaving the car "ignition on" for a long time.
• Restore original after the job – especially if the car is to be handed over to a customer or inspected.

FAQ – frequently asked questions

1) Do I have to use the bypass's OBD port?

Yes, in most cases. When the bypass harness is connected inline, the bypass's OBD connection provides the path around the SGW.

2) Can I damage the car with an SGW bypass?

If connected correctly, the risk is small, but you can create fault codes or damage clips/pins if you pull/force connectors. Work methodically and carefully.

3) Do I need to disconnect the battery?

Not always. Many people manage this with the ignition off and a few minutes of waiting. If you are unsure or working near sensitive electronics, the negative terminal can provide extra safety.

4) Where is the SGW located on my car?

Often behind a panel near the OBD socket, sometimes behind the glove compartment/center console. Placement varies between models and model years.

5) Does the bypass work with all diagnostic tools?

The bypass "opens the door," but your tool must still support the car and modules. If your tool lacks support, the bypass will not help.

6) I can read engine fault codes but not ABS/SRS – is it the SGW?

Often, yes. It's a classic sign of an SGW lock or limited license in the diagnostic software.

7) Can I leave the bypass connected permanently?

The recommendation is normally no. Restore the original setup after work to maintain the car's intended security level and reduce the risk of loose connections/rattles.

8) Do I have to remove any panels?

Yes, almost always. The SGW is rarely "exposed" but rather behind some form of protective panel.

9) I only get contact sometimes – why?

Usually a loose connection (connector not fully seated), cable under tension, or the car switching between active/sleep mode. See the troubleshooting table above.

10) Does the bypass affect the car's start/immobilizer system?

Normally not when correctly connected and used for diagnostics. However, incorrect connection or loose connections can create communication errors.

11) Do I need internet?

Not for the bypass itself. But some diagnostic software or licenses may require internet for login/activation.

12) Is this the same as "unlocking" the ECU?

No. SGW bypass is about the communication path for diagnostics. ECU unlocking/flashing is a different process that depends on the ECU type, software, and tools.

13) Can the bypass provide better live data?

It can give you access to more modules that have live data (ABS, BCM, SRS, etc.). The actual data quality depends on the diagnostic tool.

14) Can I clear airbag fault codes with the bypass?

If your diagnostics support it and the fault has been rectified, yes – otherwise the code will return.

15) Why does it say 12+8 pin – what does that mean?

It describes the number of pins on the SGW-side connectors: one 12-pin and one 8-pin connector.

16) I see a different connector combination in the car – what do I do?

Then you likely have a different SGW variant. Do not use the 12+8 bypass if the connectors do not match.

17) Do I need to clear fault codes afterwards?

Sometimes. Communication codes can arise when modules are disconnected/reconnected. Clear them when the car is restored.

18) What is the most common mistake?

Not pushing the connectors all the way until they lock, or trying to diagnose via the car's regular OBD socket instead of the bypass port.

19) Can I use the bypass for service functions (EPB, DPF, etc.)?

Bypass can make it possible, but only if your diagnostic tool supports the function and the correct car.

20) How do I know that the bypass is actually working?

The clearest sign is that after connecting, you can connect to modules that were previously blocked (e.g., ABS/BCM/SRS) and read live data/fault codes.

Quick summary

1. Ignition OFF, wait 2–5 min.
2. Locate the SGW (12-pin + 8-pin connectors).
3. Disconnect original connectors from SGW.
4. Connect the bypass inline (car's connectors → bypass, bypass → SGW).
5. Connect diagnostics to the bypass's OBD port.
6. Ignition ON, run diagnostics, test locked modules.
7. Restore original after work.