Over the course of a long development process involving teams on two continents, we engineered into the Zolfe car a Mazda powertrain that is running all of the Mazda emissions equipment and is passing the OBDII self-test.
The Zolfe prototypes running in the UK are fitted with a Ford Duratec motor, which means the chassis is wired to match the Ford's electrical system.
After importing the car to the US, the chassis is fitted with a Mazda MZR 170-bhp 2.0-liter engine and 6-speed manual transmission normally found in 2006 - 2009 Mazda MX-5's.
The Zolfe uses a classic set of individual gauges made by CAI, who own the Smiths name today. These gauges all use discrete signals. The Mazda running gear on the other hand has a mixture of discrete signals, CAN bus data, OBD data, and must pass mandated emissions tests. Grafting the two systems together required a significant amount of engineering and development effort.
The Mazda electronics functionality is divided between the engine ECU and the dashboard cluster. For the engine to even turn over requires a series of events has to occur in the proper sequence beginning with the function of the immobilizer system in the key fob.
In addition to the standard OEM parts like the ignition immobilizer system, other parts such as the evaporative pump, canister and vent system had to be properly engineered and installed on the prototype vehicles. It didn't end there. The rest of the emissions equipment had to be properly engineered and installed and functioning for the OBDII system to report back no faults.
To keep the system as close to the Mazda OEM as possible, the stock Mazda ECU, sensors, and connectors are all maintained where possible. Interface harnesses, jumpers, and other wiring bits were constructed using DTM connectors and other high-quality components.
The engine is running without fault codes, the emissions equipment is functioning, and the car drives like a dream.