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Thread: HP USB Port Failure Lessons Learned & Fix

  1. #1

    Default HP USB Port Failure Lessons Learned & Fix

    A while back I had a problem with my HP ECU that I was able to resolve, and in case anyone else has experienced the same problem I wanted to pass on the work-around fix that I had success with.

    The HP is installed in my Willys street rod, and it had been working well for over three years with no problems. I don't use a Digital Dash or touchscreen, but instead I use a small notebook computer for all my real-time in-car tuning and datalogging. I also use a larger (easier to see the screen) laptop computer to view all of the datalogs and for tuning changes. I had been using the USB connector on the HP to interface with the computers, and it always worked without any issues.

    Then one day the USB port stopped working. I used it one evening and it worked fine, and the next day I could not connect with the laptop. Since I purchased my EFI setup from Hilborn Fuel Injection and they have been very helpful in supporting their (and Holley's) products. I gave Andy, their EFI specialist a call and relayed my problem. After trying three different USB cables, two separate computers, and different USB ports on those computers, we determined that the USB port on the HP had stopped working.

    Andy told me that there was another way to have the HP communicate with the laptop, and that it was possible to use the CAN Bus connector instead of the USB port on the HP. I'd need to get part #558-443 "CAN to USB Dongle" cable that would allow me to connect the HP to the laptop. I ordered the cable, and when I got it I saw that there was a compatibility problem. The connector on the main harness had a Metri-Pack 150 connector, and the connector on the cable was a Mizu P25 style.

    I purchased my Hilborn/Holley EFI setup with a #558-104 main harness back in mid-2012, and at the time the CAN connector on that harness was the Metri-Pack. However, looking at the latest wiring diagram for that same harness, Holley is now showing a 4-wire P25 connector. I just happened to have an older harness with the older CAN connector.

    A call back to Hilborn put me on the right track again. It seemed that I needed another adapter. This time I ordered up a #558-430 "CAN Adapter/Power Harness" cable. This would adapt the two-pin Metri-Pack main harness connector to the four pin Mizu P25 connector on the 558-443.

    When I got this cable, it had four wires, and after reading the instructions, I determined that I did not need to use the power and ground wires, only the two CAN Hi and CAN Lo wires. I removed the two unnecessary wires and plugged everything together. I also needed to upgrade my software/firmware from V4 to V5 to make use of the new CAN/USB setup.
    It all worked, and I could again communicate with the HP ECU via my laptop. In hindsight, I would not have purchased the 558-430 as it was not really needed. To do again, I would cut off the P25 connector and replace it with a corresponding Metri-Pack two pin connector that would mate up with the main HP harness directly.

    Maybe over the winter when the car is off the road, I’ll call Holley and perhaps send the HP back to see if the USB port can be fixed. Until then this setup works okay, and it didn’t stop me from using the Willys in the meantime.

  2. #2
    Join Date
    Dec 2009


    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

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