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Renix

From Alfawiki
Renix Electronique
Company typeJoint venture
IndustryAutomotive electronics
Founded1981 in Toulouse, France
FounderRenault, Bendix
FateAcquired by AlliedSignal (Bendix's parent company)
SuccessorBendix Electronics and Engine Controls
Headquarters
Toulouse
,
France
Area served
Worldwide (notably Renault, Volvo, AMC/Jeep)
ProductsElectronic ignition systems, fuel injection units, electronic automatic transmission controllers, engine sensor technology
OwnerInitially Renault (51%) and Bendix (49%), later AlliedSignal
ParentInitially joint venture; later AlliedSignal/Bendix

Renix (Renix Electronique) was a collaborative enterprise formed by Renault and Bendix that specialized in the development and production of automotive electronic ignition systems, fuel injection units, electronic automatic transmission controllers, and engine sensor technology. Its components were predominantly installed in Renault and Volvo vehicles, while in the United States, the Renix brand became particularly linked to the computerized fuel injection and engine management systems used in AMC/Jeep’s 2.5 L I4 and 4.0 L I6 powerplants.

Use of name

The term Renix refers to multiple automotive control technologies. In some carbureted Renault and Volvo models, it identifies an electronic ignition system that incorporates an engine control unit (ECU) replacing conventional contact breaker points. This system requires no maintenance, utilizing an angle sensor along with various fuel sensors; its sealed ECU is not serviceable, and its EPROM cannot be updated.

Subsequently, Renix described a fuel injection system integrating an ECU with a range of sensors. This technology first appeared in Renault engines ( and ), powering vehicles such as the Renault 21, 25, and Espace. Within the U.S. market, it became well-known through its application in AMC’s 4.0 L () inline-six engines starting with the 1987 Jeep Cherokee (XJ). This setup followed AMC’s Computerized Engine Control system and preceded Chrysler’s Mopar MPI.

Renix Electronique

Founded in 1981 as a joint venture with Renault holding a 51% stake and Bendix owning 49%, Renix Electronique was based in Toulouse. Its North American branch, Renix Corporation of America, handled sales, logistics, engineering support, and quality assurance for AMC.

After Renault encountered financial challenges in 1985, it sold its interest in Renix to AlliedSignal, Bendix’s new parent company. AlliedSignal purchased Renault’s 51% share for US$200 million, incorporating Renix into Bendix Electronics and Engine Controls. Following this acquisition, Renix Corporation of America was merged into AlliedSignal. Despite these changes, Renix products continued to be produced in France and distributed worldwide under the Bendix brand.

In 1988, the French Bendix manufacturing site was sold to Siemens VDO. Later on, Siemens AG divested its VDO division to Continental Automotive Group in 2008.

Renault applications

The Renix system was implemented in F series engines installed in the Renault 19 16V, Renault 21, Renault 25, and Renault Espace. This multi-point fuel injection setup utilized multiple sensors for air flow, throttle position, and detonation detection coupled with an advanced computer. Introduced in 1984—three years before its American debut—it boosted the power output of the carbureted engine from to . The system was also employed on 2.2 L engines used in R21, R25, and Espace models.

Additionally, the Renix fuel injection combined with a Garrett turbocharger powered the mid-engine V6 found in the Renault Alpine GTA/A610 sports car.

AMC/Jeep applications

Renix provided a fully integrated electronic engine management system that included a solid-state Ignition Control Module (ICM), distributor assembly, crankshaft position sensor, and an Electronic Control Unit (ECU) equipped with a sophisticated microprocessor for its era. The system featured an engine knocking sensor allowing adaptive spark timing adjustments on a per-cylinder basis to prevent detonation. Knock detection employed a wide-band accelerometer mounted on the cylinder head, enhancing signal quality through angular discrimination techniques.

Compared to later Mopar systems, Renix offered greater input complexity. Its knock sensor automatically optimized spark advance individually for each cylinder, occasionally improving Fuel economy in automobiles when using higher octane fuels. The design of AMC’s 4.0 L I6 engine allowed performance upgrades such as camshaft replacements without requiring significant ECU modifications.

Initially introduced in 1986 on AMC’s 2.5 L four-cylinder engines, Renix enhanced both power delivery and drivability on vehicles like the Jeep Cherokee and Jeep Comanche. It remained standard through the 1990 model year but had limited diagnostic compatibility—only Chrysler’s DRB diagnostic tool could communicate with pre-1991 Renix systems.

Model years:
  • 1986 - Standard Renix throttle body injection (TBI) on Jeep 2.5 L AMC four-cylinder engines
  • 1987 - Debut of Renix-controlled 4.0 L inline-six rated at and torque
  • 1988 - Power increased to and torque through higher compression ratios
  • 1989 - Transitioned to Renix multipoint fuel injection (MPFI)
  • 1991 - Replaced by Chrysler HO EFI featuring OBD-I compliance

Renix engine management was exclusive to Jeep Cherokee and Comanche models equipped with AMC engines from 1986 through 1990. The GM V6-powered vehicles utilized OBD-I General Motors controls, while early Renault turbodiesels had separate control systems.

The Jeep Wrangler (YJ) adopted the AMC 4.0 L inline-six paired with Chrysler electronics only starting in 1991; earlier versions continued using carbureted AMC engines. No other Jeep models incorporated Renix electronics during this period.

Operation

In standard Jeep configurations, the ignition control module (ICM) is positioned within the engine bay. This module incorporates a solid-state ignition system along with a built-in ignition coil that can be replaced independently. The ECU sends electronic commands to the ICM to adjust ignition timing according to the engine’s power demands. Upon receiving a signal from the ECU, the ICM generates a tachometer output and delivers a high-voltage pulse from the coil to the distributor. The crankshaft position sensor, mounted securely with specialized bolts to the flywheel or drive plate housing, detects both TDC and BDC positions as well as engine speed; this sensor is fixed and cannot be adjusted.

Inspection stations

The Renix control system predates OBD standards and does not feature a "Check Engine Lamp." It lacks the capability to store or present Diagnostic Trouble Codes (DTCs) or Parameter IDs (PIDs), which creates difficulties during vehicle inspection procedures, particularly in regions like California with stringent emission standards. Many inspection facilities are unaware of this limitation and may mistakenly report that the CEL/MIL is malfunctioning.

Skoda applications

During the 1980s, Skoda manufactured rear-engine vehicles equipped with Renix fuel injection systems. Although initially designed for the Canadian market, these models—such as the 135 GLi and 135 RiC—were also sold across Europe. Replacement fuel system components remain accessible through Chrysler-Jeep dealerships.

Volvo applications

The Volvo 700 Series along with certain Volvo 300 Series variants utilized a B200K 2.0 L inline-4 naturally aspirated engine featuring Renix ignition. The 300 series, largely assembled in the Netherlands and Malaysia, was never marketed in the United States. All gasoline-powered Volvo 300 series vehicles employed Renix/Bendix ignition systems from 1983 until production ceased in 1991.

Volvo "Redblock" engines equipped with Renix ignition include:

  • B200K 1986 cc with Solex Cisac Z34 twin-barrel carburetor (1985–1989)
  • B200E 1986 cc featuring Bosch LE-jetronic fuel injection (1985–1989)
  • B200F 1986 cc with Bosch LU-jetronic injection and catalytic converter (1987–1990)
  • B230K

Renault-based engines utilizing Renix ignition:

  • B18E(D) 1721 cc OHC engines in the 400 series (1986–1988)
  • B172K 1721 cc OHC with Solex Cisaz Z32 twin-barrel carburetor (1986–1989)
  • B14.4E/S 1397 cc OHV using Weber 32DIR twin-barrel carburetor (1985–1991)
  • B14.3E/S 1397 cc OHV equipped with single-barrel Solex carburetor (1983–1985)
  • B13.4E 1289 cc OHV fitted with Weber 32DIR twin-barrel carburetor for Finnish tax classification (1989–1991)

The B172K and B18 engines were derived from Renault FnN designs, while the B14.x series originated from Renault C1J units; all underwent modifications by Volvo for their specific uses.

See also

References

  • Boccadoro, V.; Kizer, T. "Adaptive spark control with knock detection," Society of Automotive Engineers (SAE) Technical Paper 840447, 1984.
  • Freeman, Kerry A. Chilton's guide to emission diagnosis, tune-up and vacuum diagrams, 1984-87 domestic cars, Chilton, 1987.
  • Mitchell's Electronic Fuel Injection Troubleshooting Guide: Domestic Vehicles (AMC/Jeep; AMC; AMC/RENIX; AMC/RENIX II), Mitchell International, 1991.

External links

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