The Open Road

Engine Immobilization Problems

GEMS Re-programming

Unlock the Power of Your Vehicle with GEMS Reprogramming or Mobi4

Are you tired of dealing with security codes to start your engine? Say goodbye to the hassle by choosing our GEMS Reprogramming service.

Why Choose GEMS Reprogramming?

When GEMS units were initially manufactured, they required a security code for engine activation. But times have changed. We’ve invested extensive research and development to provide a solution that allows you to bypass the security code requirement, making your life easier.

What Can You Expect?

Sending your GEMS unit to us is all it takes. Once it’s on our test bench, we’ll work our magic, and your unit will be returned to you, ready to start the engine without any security code hassles.


  • No more fumbling with security codes
  • Quick and easy engine activation
  • Ideal for after-market repairs

How Does it Work?

  1. Arrive at the stranded vehicle
  2. Open the bonnet (hood)
  3. Remove the existing GEMS unit
  4. Install your newly reprogrammed GEMS
  5. Remove the start relay and connect terminals 30 and 87 with a start push button on long wires
  6. Close the bonnet (hood)
  7. Get into the driver’s seat
  8. Turn the ignition key and push the start button
  9. The engine starts, and you’re good to go!

In case your BECM (Body Electronic Control Module) is unresponsive, we’ve got you covered. Simply remove the ignition on the relay and place a bridge between terminals 30 and 87 to turn the ignition on. Drive back to your workshop, diagnose the issue, and fix it at your convenience.

Note for International Customers:

Reprogramming services outside of Australia may incur additional costs due to expensive freight, postage, and insurance charges for parcels exceeding 2 kg. Please don’t hesitate to contact us for a quote.

Unlock the full potential of your vehicle with GEMS Reprogramming. Say goodbye to security code headaches and enjoy a hassle-free driving experience. Get in touch with us today!

Introducing the Mobi4 – Your Ultimate Vehicle Security Solution

Upgrade your vehicle’s security with the Mobi4, a cutting-edge device designed to give you complete control and peace of mind. Whether you want to safeguard your Range Rover, transplant your engine into another vehicle, or use it as a stand-alone unit, the Mobi4 has you covered.

Say goodbye to immobilization issues with the GEMS, because the Mobi4 eliminates them. With a simple ‘security code re-learn,’ you can start your engine effortlessly, even if your BECM is in alarm mode, dead, or removed. The Mobi4 sends the coded bitstream to the GEMS, ensuring smooth operation.

In case your BECM is in alarm, immobilized, dead, or removed, our detailed By-pass instructions tab will guide you through the process of initiating ignition and starting the engine.

What sets the Mobi4 apart is its innovative design, capable of operating in extreme temperatures, ranging from below freezing to a scorching +120 degrees Celsius. It’s built to withstand whatever conditions you face.

Order the Mobi4 now and take advantage of our optional Security Relearn Tool. We can send it to you on loan so you can perform a security relearn on your own. Once you’re done, simply return the tool, and we’ll refund your $200.00 deposit. Please note that the Security Relearn Tool is compatible only with GEMS in Range Rovers, as it needs to communicate with both the BECM and the GEMS.

Before you order the Relearn Tool, take a moment to check your vehicle’s diagnostic socket for signs of moisture or corrosion. Use a mirror and a flashlight to inspect the socket visually. If you detect any water or corrosion, order and install a Data replacement diagnostic connector to avoid contaminating the plug of our Security Relearn Tool. We’re committed to delivering a reliable tool and protecting your vehicle’s diagnostic socket.

Don’t compromise on your vehicle’s security. Choose the Mobi4 for unmatched peace of mind and reliability.

Introducing the Mobi4 & Relearn Tool

Unlock the convenience of security relearning with our Mobi4 & Relearn Tool.

Would you like to take control of your security relearn process? We offer you the option to borrow our Security Relearn Tool, allowing you to perform a security relearn at your own pace. After you’ve completed the process, simply return the tool to us, and we’ll refund your $200.00 deposit in full. For more details, please refer to the Security Relearn Tool tab.

Please note that the Security Relearn Tool is compatible only with GEMS-equipped Range Rovers. It is essential for the tool to communicate effectively with both the BECM and GEMS systems for proper functionality.

Before placing an order for the Relearn Tool, we strongly recommend checking the diagnostic socket in your vehicle for any signs of moisture or corrosion. Use a mirror and flashlight to inspect the socket thoroughly. If you detect any traces of water or corrosion, we advise ordering and installing a Data replacement diagnostic connector. Plugging our Security Relearn Tool into a contaminated diagnostic socket may compromise its performance and result in additional cleaning or replacement costs upon return. We are committed to ensuring that our tools function optimally and do not affect the diagnostic sockets of other vehicles. For more information, please refer to our DATA section.

Experience the ease of security relearning with the Mobi4 & Relearn Tool and ensure your Range Rover remains in top-notch condition.

Connecting Mobi4 to GEMS: A Hassle-Free Guide

Introducing Mobi4, a cutting-edge device designed and manufactured in Australia with the highest-quality components, capable of operating in a wide temperature range from below freezing to +120 degrees Celsius. We’re confident that Mobi4 will resolve the previous hot restart issues experienced with Mobi2 when installed in GEMS. Your feedback is highly appreciated.

Let’s get started with the connection process:

  1. Power Connection:
    • Ensure the ignition is turned on.
    • Locate the 18-pin black connector at the end of the ECM (Electronic Control Module), and find pin 7.
    • Solder the red power wire from Mobi4 to the large brown wire with an orange trace in this connector.
  2. Security Code Setup:
    • We no longer use the originally coded bitstream from the BECM (Body Electronic Control Module).
    • Cut the black wire in Pin 26 of the 36-pin red connector.
    • Solder the black wire going from GEMS to the white wire (coded bitstream out) from Mobi4, and ensure the connection is insulated.
    • Securely tie back and insulate the unused black-coded bitstream wire from the BECM.
  3. Ground Connection:
    • Shorten the long black earth wire from Mobi4.
    • Solder it to any one of the four black wires in the 18-pin black connector at the end of GEMS.
  4. Security Re-learn:
    • After wiring Mobi4 to the GEMS unit, you’ll need to perform a Security Re-learn with the GEMS.
    • This step is necessary for the GEMS to learn the new security code sent by Mobi4.
    • A security re-learn requires a diagnostic tool capable of putting the GEMS into security re-learn mode.
    • Most Land Rover aftermarket repairers have these diagnostic tools, so your repairer can likely assist you.
    • Alternatively, you can order a loan Security Relearn Tool to perform the security re-learn yourself.


  • Our Security Relearn tool is compatible only with GEMS in a Range Rover.
  • It must be able to communicate with both a BECM that is not in alarm or immobilized and the GEMS for it to work.
  • While rare, there have been a few reported cases where GEMS units did not go into Security Relearn mode.

For visual reference, please see the accompanying image. If you have any questions or encounter any issues during this process, feel free to reach out for assistance. Your satisfaction is our priority.

Connecting Mobi4 to BECM: A Step-by-Step Guide

To ensure a seamless connection between your Mobi4 device and the BECM (Body Electronic Control Module), follow these instructions:

Power Connection:

  1. Turn on the ignition.
  2. Locate the red wire on your Mobi4 device. This wire needs power when the ignition is switched on.
  3. Solder the red wire from the Mobi4 to one of the following BECM wires below:
    • The white/purple wire from pin 1 of the 12-way grey connector (C-323) on the front (electro-chromatic rearview mirror).
    • The green wire from pin 4 of the 4-way natural connector (C-324) on the front (illuminated mirrors in sun visors).
    • The green/grey wire from pin 1 of the 14-way yellow connector (C-120) on the front (SRS).
    • Any of the white wires from pins 1, 2, or 3 on the 12-way white connector (C-625) on the inside.
    • The white wire from pin 9 of the 10-pin white connector (C-258) on the rear.
    Note: Not all Range Rovers have all of these wires and their associated features.

Earth Connection:

  1. The long black wire from the Mobi4 must be connected to earth.
  2. You can either:
    • Solder it to the thick black earth wire on the outside rear of the BECM, OR
    • Fit an eye terminal, drill a hole in the seat base, remove the paint from around the hole, and attach the eye terminal with a self-tapping screw or nut and bolt.
    Note: We do not recommend removing the black earth terminal at the rear of the BECM, as it may cause problems when reconnected.

Security Code Connection:

  1. Locate Pin 5 of the 16-pin green connector (C-112) on the front of the BECM. This pin has the black wire that sends out the coded bitstream to the GEMS.
  2. Important: If you need to drive to a repairer for a security re-learn, leave this connection for them to complete.
  3. Cut the black wire between the BECM and the GEMS, leaving enough length on the BECM end to reconnect it if needed.
  4. Solder the white wire from the Mobi4 to the black wire going to the GEMS and insulate the connection.
  5. Tie back and insulate the end of the unused black wire from the BECM.

Security Re-learn:

  1. After wiring the Mobi4 to the front of the BECM, a Security Re-learn is required with the GEMS.
  2. This ensures that the GEMS learns the new security code from the Mobi4.
  3. A security re-learn necessitates a diagnostic tool capable of putting the GEMS into the security re-learn mode.
  4. Your repairer can likely perform this, as most Land Rover aftermarket repairers have the necessary tools.
  5. Alternatively, you can order a loan Security Relearn Tool and perform the security relearn yourself.Note: The Security Relearn Tool works only with the GEMS in a Range Rover and requires communication with both a non-alarm or immobilized BECM and the GEMS to function.

Please refer to the “Intermittent Non-start” tab for information on addressing problems with gold plating on the terminals connecting the BECM and the GEMS.

With these steps, you’ll have your Mobi4 seamlessly connected to your BECM, ensuring proper functionality and peace of mind.

Installation of Device Bypass for BECM Troubleshooting

To ensure seamless operation of your vehicle’s BECM (Body Electronic Control Module) and prepare for any potential BECM issues, you can install a bypass system. This guide will walk you through the steps required to install bypass switches that can temporarily circumvent BECM-related problems.

Materials Needed:

  • ON/OFF switch
  • Normally open push button
  • Two additional wires
  • Soldering equipment
  • Insulation material

Step 1: Preparing the Bypass Wires

  1. Begin by reprogramming your GEMS (Generic Engine Management System) to eliminate the need for security codes or install a Mobi4 system and complete a successful security relearn.
  2. Next, add two wires to your BECM near the connectors. These wires will be used for the bypass system.
  3. Solder the bypass wires to the existing wires near the connectors and insulate the soldered joints properly.
  4. Extend these wires so that the ON/OFF switch and push button can be conveniently located near the front of the seat for easy access.

Step 2: Wiring for Ignition Relay Bypass 5. To enable the Ignition Relay in the engine bay fuse box, connect the white wire on pin 8 of the 10-pin white connector (C-258) at the rear of the BECM to the white wire on pin 9 of the 14-pin yellow connector (C-120) at the front of the BECM.

  1. When you turn the ignition key to the ‘Ignition ON’ position and activate the bypass switch, the signal will bypass the BECM, allowing the Ignition Relay to operate. With the bypass switch in the off position, the BECM functions normally.

Step 3: Wiring for Starter Relay Bypass 7. To operate the Starter Relay in the engine bay fuse box, connect the white wire with the red trace on pin 6 of the 20-pin yellow connector (C-257) on the outside of the BECM (under the fuses) to the white wire with the red trace on pin 2 of the 10-pin yellow connector (C-113) at the front of the BECM.

  1. When you turn the ignition key to the ‘Start’ position and press the bypass push button, the signal will bypass the BECM, activating the Starter Relay and cranking the engine.

Caution: Before using the bypass push button, ensure the following:

  • The handbrake and footbrake are engaged.
  • For manual transmissions, ensure the transmission is in neutral and the clutch is depressed.
  • For automatic transmissions, ensure the transmission is in either neutral or park.

By following these steps, you can install a bypass system that provides a backup solution for BECM-related issues while maintaining safety precautions. Enjoy peace of mind knowing you’re prepared for any BECM trouble that may arise.

Security Relearn Tool

The Security Relearn Tool is a crucial device designed exclusively for Range Rover vehicles equipped with GEMS technology. It plays a pivotal role in ensuring the seamless communication between the Body Electronic Control Module (BECM) and the GEMS system. To achieve optimal results with this tool, it is imperative that the BECM is not in alarm or immobilized mode.

If you plan to transplant the engine into a different vehicle or utilize it as a standalone unit, a necessary step is to connect the Mobi4 to the GEMS unit and perform a security relearn before detaching the GEMS and engine from the Range Rover. Failing to disconnect the coded bitstream wire from the BECM to the GEMS may lead to confusion, as both systems will receive conflicting codes.

Here’s a step-by-step guide on how to use the Security Relearn Tool:

  1. Connect the diagnostic plug from the Security Relearn Tool to your vehicle’s clean and dry diagnostic socket.
  2. Turn the ignition key on and observe the LED on the Security Relearn Tool. A flashing green/blue LED indicates that the GEMS system has successfully entered Security Learn Mode. However, if the LED flashes red, it signifies a communication error, which should be addressed by checking the 5-amp fuse 33 in the engine bay fuse box and reviewing the intermittent non-start tab. Ensure all nominated terminals in the BECM, body, and engine harness connectors are correctly treated. It may be necessary to double-check the Mobi4 connections and repeat the instructions as needed.
  3. Verify that the engine starts upon receiving a security code from the Mobi4 and allow it to run for a minimum of 5 minutes to store the new code in memory.
  4. Turn off the ignition and unplug the Security Relearn Tool.

After completing these steps, it’s crucial to ensure that the engine starts without requiring a security code from the BECM.

In the event that the Security Relearn Tool encounters a communication error or you face difficulties in getting the GEMS system into Security Learn Mode (provided the BECM is not in alarm or immobilized), follow these additional steps:

  1. Remove the GEMS unit, following the “Remove and Refit” instructions.
  2. Send the GEMS unit, Mobi4, and Security Relearn Tool to us. Our workshop will attempt a Reprogram on a test bench to resolve the issue.

Please note that instances of the GEMS unit failing to enter Security Relearn Mode are exceptionally rare. If you encounter persistent issues, our dedicated team is ready to assist you in resolving them.

To safeguard the integrity of the Security Relearn Tool and ensure a hassle-free experience, be sure to return it to us at your own expense, using a tracking method and insurance, for a refund of AU$200.00. We will promptly issue a full refund upon satisfactory testing and inspection, provided that the tool is free from contamination.

Before ordering the Security Relearn Tool, we recommend checking the diagnostic socket in your vehicle for any signs of moisture or corrosion. If such signs are present, it is advisable to order and install a Data replacement diagnostic connector. Connecting the Security Relearn Tool to a contaminated diagnostic socket can compromise the tool’s functionality and necessitate cleaning or replacement at an additional cost.

For further information on addressing communication errors, please refer to the provided error codes and instructions under “Communication error.” We are committed to ensuring the effectiveness and reliability of your Security Relearn Tool, as your satisfaction is our top priority.

Removing and Refitting Your GEMS Unit in a P-38 Range Rover

When it comes to your P-38 Range Rover, knowing how to properly remove and refit the GEMS (Generic Engine Management System) unit can be a valuable skill. This guide will take you through the process step by step, ensuring a smooth and hassle-free experience.

Step 1:

Preparing for the Procedure First things first, turn off the ignition key. You don’t need to disconnect the battery, as the GEMS box loses power approximately 20 seconds after the ignition is turned off. Please note that the GEMS location may vary for different vehicles; these instructions are specifically for the P-38 Range Rover.

Step 2:

Access the Engine Bay Open the hood to access the engine bay where the GEMS unit is located.

Step 3:

Removing the GEMS Unit a. Loosen the screws at each end of the long, narrow, black cover located behind the battery. Carefully remove the cover and check the sealing gasket for reusability. b. Locate the three GEMS connectors on top of the GEMS unit. To disconnect them, depress the release latch on the side of each connector and gently wiggle them off. Start with the large black connector, then the red one, and finally the small black connector. Be patient, as they may require a bit of effort to come off. c. With all three connectors removed, carefully slide the GEMS unit up and out of its housing. If you also removed an anti-rattle clamp with the GEMS unit, make sure to return it to the black box.

Step 4:

Preparing for Re-Programming To send your GEMS unit for re-programming, protect it by taking the following steps: a. Cut and place a couple of layers of corrugated cardboard over the three connectors on the side of the GEMS unit. b. Wrap the entire unit in bubble wrap to provide added protection during transit.

Step 5:

Refitting the GEMS Unit Once your GEMS unit has been reprogrammed and returned, it’s time to re-install it in the engine bay. a. Place the returned GEMS unit back into the black box. b. Reconnect the three connectors to the GEMS unit.

Step 6:

Final Wire Insulation There’s one last task to complete: insulating a wire in the RED connector. In the second chamber from the end (next to the larger BLACK connector), you’ll find a BLACK wire. a. Cut the BLACK wire a short distance from the connector, leaving room for potential reattachment. b. Fold each end of the BLACK wire back over itself to form a “J” shape. c. Slip one of the two supplied insulating sleeves over each of the two wire ends to ensure proper insulation.

With these steps, you’ve successfully removed, reprogrammed, and refitted your GEMS unit in your P-38 Range Rover. This process may seem intricate, but following these clear and concise instructions will help ensure that your vehicle’s engine management system operates smoothly and efficiently.

Resolving Intermittent Non-Start Issues: A Quick and Effective Solution

If you’ve been grappling with an intermittent non-start issue in your vehicle, there’s a good chance it’s related to corroded signal wire terminals. Specifically, the problem lies in the gold-plated terminals connecting the Body Electronic Control Module (BECM) to the Generic Engine Management System (GEMS). Over time, corrosion tends to build up between the gold plating and the base metal of these terminals, compromising their electrical integrity.

The good news is, there’s a simple and proven fix. While disconnecting and reconnecting the wires might provide a temporary remedy by displacing some of the insulating corrosion, a more permanent solution involves applying a minute amount of contact treatment solution to these gold terminals. This practice has been tried and tested for years, and it works wonders in preventing further issues.

Here are the key terminals you need to treat:

  1. Pin 5 of the 16-pin green connector (C-112) on the front of the BECM: This connects to a black wire responsible for transmitting a coded bitstream to pin 26 of the 36-pin red connector on the GEMS, passing through pin 1 of the body/engine harness connector.
  2. Pin 22 of the 36-pin black connector on the GEMS: This is connected to a black wire with a yellow trace that sends an “OK” signal back to pin 5 of the 20-pin green connector (C-114) on the front of the BECM, traveling through pin 4 of the body/engine harness connector.

The body/engine harness connector can be found under the engine bay, usually beneath the coolant expansion tank.

Here’s how the immobilization system operates normally:

  1. When you turn the ignition key, the BECM continuously transmits a coded bitstream to the GEMS until it acknowledges the code as valid.
  2. Upon receiving a valid code, the GEMS responds with an “OK” signal to the BECM.
  3. The BECM then illuminates the Check Engine lamp, stops transmitting the coded bitstream, activates the starter relay, and allows the engine to crank when the key is in the start position.
  4. For the engine to start and run, the GEMS enables the ignition and injection.

However, when the BECM is in alarm or immobilized:

  1. The BECM refrains from transmitting the coded bitstream.
  2. As a result, the GEMS, not having received a valid code, neither injects fuel nor activates the ignition system.
  3. Furthermore, the BECM, not having received the “OK” signal from the GEMS, will not turn on the Check Engine lamp or allow the engine to crank over.

To resolve this intermittent non-start issue, it’s crucial to treat the specified gold-plated terminals with a contact treatment solution designed for gold contacts. You can find suitable products at Jaycar stores, such as the Deoxit ProGold product, or you can check with your local electronics store for a contact treatment solution typically used on gold connectors in audio/visual equipment.

In a nutshell, addressing this issue is as simple as applying the right treatment to the right terminals, ensuring a smoother and more reliable starting experience for your vehicle.

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You are responsible for covering the return costs of both reprogramming and the Re-learning tool. The total charge for the Mobi4 and loan of a Re-learning tool involves a $250 deposit. Please note that you will need to handle the return of the Re-learning tool.