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Connecting COMPUSHIFT to Holley Sniper 2


This guide provides details on setting up a COMPUSHIFT Sport or COMPUSHIFT Pro with a Holley Sniper 2.

The two control systems are connected together using CAN bus, and signals like throttle position and engine speed are automatically transferred between the two units. No other connection is required.

Setup Instructions

  1. Ensure that both the COMPUSHIFT and Sniper 2 are powered by the same switched ignition power.

  2. Connect the HGM CAN-21 cable between the Holley Sniper EFI M8 display connector and the Holley Sniper display using the provided T connector. Do not connect to other M8 connector on the Holley EFI.

  3. Connect the gray Deutsch receptacle on the CAN-21 cable to the mating CAN bus plug on the COMPUSHIFT controller harness.

  4. Turn on the key, but do not start the engine.

  5. On the COMPUSHIFT Setup app and navigate to the “Vehicle Setup” menu.

  6. Ensure that the transmission type is set correctly.

  7. Set the engine type on the COMPUSHIFT controller to “Holley Sniper/EFI CAN” or “Holley TerminatorX” as required.

  8. Navigate to the dashboard on the setup app or handheld display.

  9. Start the engine. Confirm that the engine speed and throttle position are reading correctly on the display.

Do NOT drive the vehicle until you have confirmed CAN communications are working properly and you have no trouble codes.

You can diagnose CAN bus problems by going to Diagnostics / Network Diagnostics on the CS Setup App. The CAN 1 Receive Count should be steadily increasing when the ECU’s are communicating correctly. The error counts should always be 0. If you do have errors, confirm that the CAN bus baud rate is set to 1000 in Network Setup.

CAN bus networks require termination resistors at both ends. On the Holley systems, termination is provided in the EFI and the display, so both devices should be connected to the CAN bus all times. Failure to keep the display connected may result in CAN bus errors on the COMPUSHIFT controller. If you need to remove the display, HGM can provide an alternative termination solution.

An incorrectly calibrated throttle position sensor (TPS) on your Holley system may report a throttle position value greater than 100% over CAN bus. This will cause a trouble code on the COMPUSHIFT controller.

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