Many Zilla’s were built with Hairballs configured for using a Hall Effect Accelerator pedal.
These Hairballs have serial numbers that end in the letter P and may be referred to as HEPA or HEPI.
Now that production is over, I can share that the HEPA Pedal comes from a Gen 2 Prius 2004 through 2009.
I’ve collected some old notes to help people since I no longer supply pedals or wiring. It may be possible for me to supply a new built cable, but I fear the costs may end up prohibitive due to the inefficiency of making one at a time. For those adventurous, the below notes should supply allneeded information to make it work.
Here are the instructions that came with the HEPA package:
HEPA Setup
Instructions to connect the Hall Effect Pedal Assembly (HEPA) to the Hairball 2 with -P option (HEPI, Hall Effect Pedal Input).
The HEPA is an automotive OEM pedal assembly with dual non contact hall effect sensors. The manufacturer name and number have been sanded off. This is our attempt to keep the manufacturer from hearing what they are being used for and cutting off our supply for liability concerns.
The HEPA only works on Hairballs which have been built with a -P option.
Important! “-P Option” Hairballs can no longer be used with a 5K ohm pot input.
Option “n” must be turned “on” in the options menu for the HEPA to function. Beware that this value will be turned “off” if defaults are reset.
The HEPA has 6 connections. They should be connected using the included 6 lead shielded wire with attached connector.
Since this feature was an afterthought, the wiring to the Hairball is a bit convoluted.
Here is how to connect the HEPA cable to the Hairball HEPI inputs:
Hairball Cable
HEPI 1 Red
Signal GND Black
HEPI 3 Green
HEPI 4 White
Chassis GND Blue
Chassis GND Bare shield wire (Silver)
HEPI 6 Orange
Some folks would like to remake the wiring so I will try to provide various old notes to assist in whatever wiring you are trying to do.
Picture of the cable with colors and locations
Here are my 20 year old txt notes on the application in case they help:
Accelerator pedal notes:
5.7.04
Pin 1 is closest to the driver.
Uses 5V input on pins 1 and 4
Ground on pins 2 and 5
Output on pins 3 and 6
Current draw 7 ma per section, Figure on 10 ma max.
Range tested at .79V to 4.4V
Standard driving range 1V to 4V
10K load on output to + or – seems to be no problem.
10.23.04
Pedal wiring on Hairball 2:
Pin 1 is closest to the driver.
Pot in – becomes HEPI 1 (Hall Effect Pedal Input, pin 1)
Pot in + Becomes HEPI 3
Signal Ground is connected to HEPI 2
Aux Pot – Beocmes HEPI 4
Aux Pot + Becomes HEPI 6
Chassis Ground gets the HEPI 5 connection.
Six wire cable from HDB has colors:
HEPI 1 Red
HEPI 2 Black
HEPI 3 Green
HEPI 4 White
HEPI 5 Blue
HEPI 6 Brown or Orange
HEPI Wiring
If your are using a Hall Effect Pedal Input you will need a -P version of the Hairball and will need to wire it as described here. The pedal requires a 6 Pin shielded wire which is included.
Pin 1 on the HEPI is closest to the driver and number 6 is at the back.
Signal Ground is connected to HEPI 2, Chassis Ground is connected to HEPI 5.
HEPI 1,3,4 and 6 are connected as labeled on the Hairball.
Cables being made of:
W506-500-ND SHIELDED 22AWG UL2464 6 COND (HEPA Cable)
Delphi Metripack. PACKARD CABLE SEAL-DARK RED #12048086
7116-4028-08 Female Copper Alloy (Au & Pd-Ni Plate) 0.35 – 0.50mm2 AWG:22-20 .22 each, 2500 broken pack plus $50. ($600) (amortize over 100 pedals for $6. each. 14 week delivery.
7283-1968-30 090-II 6P -Sealed Connector ordered 60 17 weeks.
3-M-FP-1/4-CLR-48 HDB heatshrink for end of wire. 2″ per unit.
Pedal is made of:
Ticona Celstran® PA6-GF30-01 30% Long Glass Fiber Reinforced Nylon 6
At the time of writing, a search for 7283-1968-30 shows someone on eBay offering a “7283-1968-30 New Fully Assembled 6-pin Connector” for $12 which seems like a great starting point.
For those who are adventurous, there is a partioally tested beta Hairball code available that has many more poorly documented options including the ability to reprogram the throttle range for single and dual inputs. This code is version HB214b3 and requires some computer savvy to install and run. Contact us if you would like that code.
10/26/25