VR Conditioner

VR (Variable Reluctance) Conditioners take the semi-sinusoidal signal generated by VR sensors and outputs a (typically) 5v square wave that can be interpreted by modern ECUs. There are many variants, including hardware built into ECUs, add-in boards, and OEM standalone styles.

Discrete

"Discrete" conditioners generally use specific components to build-out a signal filter to generate the needed wave form.

Examples

Built in uaEFI module

MAX9924/9926

Many VR Sensors are based on the ICs created by Analog Devices / Maxim Integrated.

"JDM" Conditioner

Typically contains special hardware to handle the "weird" signals of certain Japanese crank sensors common on Toyotas and Hondas.

HEI 7/8

THE HEI 7 OR 8 IGNINTION MODULES WERE MADE BY GM IN THE 90S AND ARE GODS OWN VR CONDITIONER. ALSO KNOWN AS SILVERBACK BANNANA OR JUST USE THIS ONE.

HEI 7

Typical use is to use the 12v/ground, VR pins, and only the signal out to condition (Pin R) VR sensors, not the actual ignition modules. The HEI 7 uses spade terminals of ?? size.

Pinout

Wiring/Circuit diagram for HEI7 ignition module

• B - Bypass Mode (used for dwell control, typically unused)
• R - Reference - 5v square wave, hall input on ECU
• E - Dwell control from ECU (typically unused)
• N - VR Sensor Negative -
• P - VR Sensor Positive +
• + - 12v, Battery (And coil positive if using)
• C - Coil negative (typically unused)
• Ground - The unit is grounded through the mounting screw

Part Numbers

Reference part number is lx315 and can be found via many sources.

General Motors 1976908

HEI 7

Basically the same as the HEI 8 module, except has full connectors and one extra pin for the ground so it is not needed to ground via the mounting screw.

Pinout

HEI 8 Module Wiring

• B - Bypass Mode (used for dwell control, typically unused)
• R - Reference - 5v square wave, hall input on ECU
• E - Dwell control from ECU (typically unused)
• N - VR Sensor Negative -
• P - VR Sensor Positive +
• + - 12v, Battery (And coil positive if using)
• C - Coil negative (typically unused)
• Ground - The unit is grounded through the mounting screw

Connectors

¹/₈" Spades for VR Sensor

The 4-wire connector to MegaSquirt-II can be bought as:

• GM: 12126487
• AC Delco: PT757
• Motormite: 85135
• PICO: 5602

The two lead connector for the small cap module is the same as the recommended CLT sensor connector:

• GM: 15306195
• AC Delco: PT1350
• Wells: 254
• NAPA: ECHTSC200
• Motormite: 85100 (Autozone (PN 047131))

Speeduino Socket

Many modules follow the 'Speeduino' style of pin layout which is a DIP-8 socket format.

Speeduino DIP8 VR Conditioner Pinout