15
Electrical Section
ECU Mounting and Wiring Considerations
The ECU should be mounted in the passenger compartment in an area where it cannot get wet. If
mounted horizontally, be sure the wiring harnesses have a drip loop to prevent water from running down
them, into the ECU. The ECU is not waterproof! If possible, mounting the ECU with the connectors
facing down gives the best protection against water ingress. Never mount the ECU on top of the radio
stack or within 3 inches of any DC motors or high pulsing current/ voltage wires or devices. The
ECU does not need any cooling or vibration isolation.
You should plan the ECU mounting to make wiring routing from it logically flow towards your firewall
grommet holes. For best possible resistance to electrical noise, we prefer to have all ECU and other low
level voltage/ current wires (thermocouples etc.) routed on one side of the firewall and all other airframe
wires which carry higher voltages and current (alternator, starter, DC motors etc.) routed on the opposite
side of the firewall and engine compartment. Never tie wrap high voltage/current wires such as the
starter, spark plug wires, alternator, strobes, radio transmitter, transponder, DC motors etc. to
any of the ECU wiring. A minimum 2 inch separation is preferred.
EM-6 ECU connectors
Injector drive Main harness Hall Programmer
Dual ECU
The dual board ECU enclosure stacks 2
boards in a single box. The upper board,
closest to the lid, is the Primary or “A”
computer. The lower, closest to the
mounting flange is the Backup or
“B”computer. The optional PC data
logging function can only be connected to the “A” computer. On 4 cylinder models using the dual board
ECU, there is no TPS, air temperature sensor, CHT sensor or mixture knob connected to the backup
computer since these are non-critical to running the engine. 6 cylinder dual board models use two air
temp and two CHT sensors, but share the TPS signal.
Dual board ECUs generally are used on engines with 2 spark plugs per cylinder. One ECU board drives
the upper plugs and the other board drives the lower plugs at all times. A relay switch box is used to
switch injector outputs between the 2 boards. The upper board is the Primary ECU, lower is the Backup.
Hole spacing for the ECU is 3.37 X 8.08 inches. Use the 10-32 stainless socket cap screws provided.
Nut plates are recommended.
SDS Programmers
The EM-6 comes with either the Design1-6.25” rectangular, or Round 3-1/8”
panel mount programmer which is used to adjust fuel and ignition timing values
and also display engine sensor data on several gauge screens. Both
programmer designs are Single ECU or Dual ECU capable as they have 2
DB9 ports on the rear to connect to the ECU be it Single or Dual ECU. The
programmer can be toggled to
either ECU as needed using the
Prog key or toggle switch(3-1/8”).
To Next Page
Loading...
