This article provides an in-depth review and installation guide for the B&M Shift Plus+ Electronic Shift Improver, a performance enhancement tool designed for 1993–1998 GM vehicles equipped with the 4L60E or 4L80E automatic transmissions. The instructions are derived from the official installation documentation and emphasize the correct procedures to achieve optimal results without compromising the integrity of the vehicle's powertrain system.
The B&M Shift Plus+ is intended to improve shift characteristics by offering firmer and more positive gear transitions. However, it is essential to understand the limitations and proper use of this device, as it is not a solution for a failing transmission. The following guide outlines the key considerations, installation steps, and supplementary product recommendations to ensure a successful and safe implementation.
Overview of the B&M Shift Plus+
The B&M Shift Plus+ Electronic Shift Improver is an add-on module designed to modify the shift behavior of GM 4L60E and 4L80E automatic transmissions. It is compatible with vehicles manufactured between 1993 and 1998 and allows the user to adjust the firmness of shifts using three distinct positions on the device:
- Position 1 (Single Dot): Provides firmer, more positive shifts compared to the stock setting.
- Position 2 (Double Dot): Offers the firmest shifts available.
- Center Position (Off): Returns the transmission to its stock shift firmness.
The device functions by altering the electrical signals sent to the transmission control system. It does not replace or bypass the vehicle’s PCM (Powertrain Control Module) but works in conjunction with it. The B&M Shift Plus+ is specifically engineered for GM 4L60E and 4L80E transmissions and must be used with the correct wiring and installation protocol.
Compatibility and Vehicle Identification
The B&M Shift Plus+ is only compatible with 1993–1998 GM vehicles that use either the 4L60E or 4L80E automatic transmissions. These transmissions are commonly found in various GM models, including trucks, vans, and sport utility vehicles. To confirm compatibility, the build code decal should be reviewed. This decal is typically located in the glove box or center console.
If the build code includes either "M30" (indicating the 4L60E transmission) or "MT1" (indicating the 4L80E transmission), the B&M Shift Plus+ can be installed. It is crucial to verify this before proceeding with the installation.
Pre-Installation Considerations
Before installing the B&M Shift Plus+, the following factors should be evaluated to ensure the device functions as intended and does not cause unintended issues:
- Transmission Condition: The device is not a cure-all for a failing transmission. If the transmission is slipping, chattering, or in poor condition, the installation of the Shift Plus+ may exacerbate the problem. It is recommended that the transmission be in good working condition before proceeding.
- PCM Location: The installation process requires access to the PCM (Powertrain Control Module), which may be located either under the hood or under the dash. The wiring must be accessed and modified accordingly.
- Wiring Integrity: Any existing wiring damage or improper connections should be repaired before connecting the Shift Plus+. Poor wiring can lead to erratic shift behavior or failure of the device.
Additionally, the B&M Shift Plus+ should not be used in conjunction with other transmission modifications that may conflict with its operation. It is advisable to consult a professional mechanic or technician if the vehicle has undergone significant transmission modifications.
Tools and Materials Required
The installation of the B&M Shift Plus+ requires a few basic tools and materials. These include:
- Scotchlok® Connectors: Used to connect the Shift Plus+ to the appropriate wiring.
- Black Electrical Tape: For insulating and securing the connections.
- Zip Ties: To route and secure the wiring safely.
- Wire Strippers and Cutters: For preparing the wires as needed.
- Multimeter (Optional): For testing continuity and ensuring proper connections.
It is also recommended that the user have access to the vehicle’s wiring diagram for the 4L60E or 4L80E transmission, as this can help identify the correct wires for connection. A basic understanding of electrical systems is beneficial but not strictly required.
Installation Steps
The following steps outline the installation process for the B&M Shift Plus+ Electronic Shift Improver, based on the official installation instructions. It is important to follow these steps carefully to ensure a successful and safe installation.
Step 1: Disconnect the Negative Battery Cable
Before beginning any work on the electrical system, it is essential to disconnect the negative battery cable. This step helps prevent electrical shorts and protects both the user and the vehicle’s electrical components during the installation.
Step 2: Locate the PCM
The PCM (Powertrain Control Module) is the central component that controls the transmission’s operation. Depending on the vehicle's year and model, the PCM may be located either under the hood or under the dash. Once located, the wire loom should be carefully removed to allow easier access to the wiring.
Step 3: Identify the Correct Wires
The B&M Shift Plus+ must be connected to specific wires within the PCM harness. According to the installation instructions, the Light Blue with White Stripe wire must be connected to the Black wire from the Shift Plus+ using a Scotchlok® connector. This connection allows the device to modify the electrical signals sent to the transmission.
It is crucial to double-check the wire colors and ensure the correct connections are made. Any errors in wiring can lead to improper shift behavior or damage to the transmission.
Step 4: Connect the Wires and Secure the Connections
After identifying and connecting the correct wires, the connections should be carefully taped with black electrical tape to prevent short circuits or exposure to moisture. The use of zip ties is recommended to route the wires safely and avoid any interference with moving parts or components.
Step 5: Reconnect the Negative Battery Cable
Once the connections have been made and secured, the negative battery cable should be reconnected. This step restores power to the vehicle’s electrical system and allows the Shift Plus+ to begin functioning.
Step 6: Test the Shift Behavior
After installation, the vehicle should be tested to ensure the Shift Plus+ is working as intended. The user can switch between the three positions on the device to observe the changes in shift firmness:
- Position 1 (Single Dot): Firmer shifts than stock.
- Position 2 (Double Dot): The firmest shifts available.
- Center Position (Off): Returns the transmission to its stock shift behavior.
It is important to monitor the transmission for any unusual behavior, such as slipping or hesitation. If any issues arise, the installation should be re-evaluated.
Recommended Complementary Products
The B&M Shift Plus+ is often used in conjunction with other performance-enhancing products to improve transmission durability and longevity. The following products are recommended for vehicles used in heavy-duty or high-performance applications:
- B&M SuperCooler Automatic Transmission Coolers: These coolers help prevent overheating, which is a major cause of transmission failure. They are especially recommended for vehicles used in towing, racing, or other high-stress applications.
- B&M Trick Shift Performance Automatic Transmission Fluid #80259: This specially formulated fluid contains foam inhibitors, extreme pressure agents, and shift improvers to enhance transmission performance and protection.
Using these products alongside the Shift Plus+ can help ensure that the transmission remains in optimal condition, especially when subjected to frequent or aggressive shifting.
Troubleshooting and Common Issues
If the B&M Shift Plus+ does not function as expected, the following troubleshooting steps may help identify the cause:
- Verify the Connections: Check that the Light Blue with White Stripe wire is properly connected to the Black wire from the Shift Plus+. Loose or incorrect connections can lead to erratic shift behavior.
- Test the Power Supply: Ensure that the negative battery cable is properly connected and that the vehicle’s electrical system is functioning correctly.
- Inspect the PCM: If the transmission is not responding to the Shift Plus+ as expected, there may be an issue with the PCM or the vehicle’s wiring harness. A professional diagnosis may be required.
- Check for Transmission Issues: If the transmission is slipping, chattering, or performing poorly, the problem may be unrelated to the Shift Plus+. In such cases, a full inspection of the transmission is recommended.
If the user is not confident in their ability to diagnose or resolve the issue, it is advisable to seek the assistance of a qualified mechanic or technician.
Conclusion
The B&M Shift Plus+ Electronic Shift Improver is a performance-enhancing device designed to improve the shift characteristics of 1993–1998 GM vehicles equipped with the 4L60E or 4L80E automatic transmissions. When installed correctly, it can provide firmer, more positive shifts without the need for major modifications. However, it is not a solution for a failing transmission and should be used with caution.
The installation process requires basic mechanical knowledge and adherence to the official instructions to ensure safe and effective operation. Users should also consider using complementary products such as transmission coolers and high-performance fluids to enhance the overall durability of the system.
By following the outlined steps and guidelines, users can successfully install and utilize the B&M Shift Plus+ to improve their vehicle’s driving experience.