AEM 30-3532 GM LS 24x Engines Layover - Manual (Page 5)

Rev A, 2013/02/05
Installation Notes
Wiring Conventions and EMI
The GM LS Engines 24x layover harness comes pre-wired with all connectors, fuses, and relays needed to operate an
engine. However, the PDC does require extension/termination of the flying leads to their appropriate devices, and
additional sensors and other devices can be wired into the harness as needed for the specific application. The following
guidelines should be adhered to while completing the required wiring.
A proper wiring job includes proper termination of the wire at the sensor. The wire terminal end must be moisture tight
where it plugs into the sensor and it must have strong, electrically sound terminals. The preferred method of securing a
wire to a terminal is to use a crimp terminal with NO solder. It is important to use the proper crimping tool for sound
terminal construction. Plastic terminal plugs must have moisture tight seals. Inspect each plug to make sure the seals are
in place. Di-electric grease can be added in the terminal slots to further aid in corrosion resistance.
If a splice into a wire must be made and no solder-less terminals are available, then you must properly solder the splice.
Noise can be a serious problem and can cause intermittent misfiring of the engine. Every precaution should be taken to
prev
ent interference to the ECU’s operation. Resistive plug leads are REQUIRED. The GM LS Engines 24X Layover
Harness comes with shielded cables for the cam and crank position sensors. These wires have shield grounds that are
grounded at the Infinity ECU plug. They are NOT grounded at the sensor end of the cable. Attempting to ground both
ends of the cable will cause a condition called ground looping and will remove any noise protection the cable has.
To eliminate or reduce the chance of EMI, wires that carry high current must run in twisted pairs. An example of this would
be the power leads from a multiple spark ignition system. These ignition systems can carry up to 100 amps for a couple
milliseconds at the time of discharge, which induces a strong magnetic field in close proximity of the wires.
The routing of the wire loom is critical to EFI system performance and safety. The following safety considerations should
be made when installing the wire loom:

Heat protection: the loom should be placed away from or insulated from sources of heat. The obvious item(s) that
should be avoided are the exhaust manifolds, EGR delivery tubes, and turbochargers. If it is absolutely necessary
to route a wire in close proximity to any of these items, then a suitable insulator must be used.

Noise suppression: do not route wires near the HT leads. For coil-on-plug ignition systems this is not as critical.

Moving component protection: route wires away from moving components such as fans, the blower belt, or the
throttle linkage. Also, make sure the wires are not under any strain when the engine is at full deflection on the
motor mounts.

Never have the wires in exposed bundles throughout the engine compartment.
Determining ECU Location

It is recommended that the ECU be placed in an environment that does not expose it to temperatures above 85°
Celsius (160F).

In cases where the Infinity is to be used in place of the stock ECU, the location that the stock ECU occupied is
suitable.

On applications where the ECU is to be located in a different position than stock, the interior of the vehicle is best.

The Infinity should be located in a place that reduces the length of extension wires from the PDC while
maintaining an environmentally sound location.

The ECU location must permit the PDC to be mounted in a serviceable location.
Power Distribution Center
The PDC contains all of the Relays and Fuses for the entire harness, and should be mounted in a location which permits
serviceability. Ideally the PDC should be located in the passenger compartment, or if necessary within the engine
compartment as far away from heat sources as can be achieved.
The PDC contains the flying lead bundle which must be wired to the battery, fuel pump and radiator fan(s), and switched
ignition. Routing of this flying lead bundle should also be taken into account when determining the mounting location of
the PDC.