Renix

Renix is an Engine Control Unit (ECU - also known as Electronic Control Unit) computer system in the AMC 4.0 liter straight 6 engines that was developed by Renault and Bendix. Production began by American Motors (AMC) with the 1987 Jeep Cherokee (XJ) models. It was preceded by the AMC Computerized Engine Control, and followed by the Mopar MPI system.

The Renix ECU has a powerful microprocessor and it was very advanced for its time. It also incorporates an engine knocking sensor that allows the computer to know if detonation is occurring, thus allowing the computer to make adaptive control by individual cylinder corrections to prevent pinging. The knock detection uses the signal from a wide bank accelerometer mounted on the cylinder head. Good signal to noise ratio is obtained primarily through angular discrimination.

The Renix computer was used through the 1990 model year. Unfortunately, the Renix system is now handicapped because there are few scan tools that can be "plugged in" to this computer for diagnosis.


History

* 1987 - the new Renix controlled 4.0 L engine was rated at 173 hp (129 kW) and 220 lb-ft (298 N·m) of torque.

* 1988 - output increased to 177 hp (132 kW) and 224 lb-ft (304 N·m) of torque, due to higher flowing fuel injectors.

* 1991 - Chrysler Corporation (then the owners of the Jeep brand) redesigned and renamed the RENIX ECU.


Other RENIX applications

* Volvo 700 series - B200K 2.0L inline-4, naturally aspirated with Renix ignition

* Renault engines