The DFI (Direct Fire Ignition) module is a device that works with your car's computer system.
It serves as a central hub for all sensors and actuators on the engine. It processes this data and combines it with other parameters such as RPM, throttle position, oil temperature, etc. The direct fire ignition (DFI) module calculates the optimal amount of fuel to be injected into the engine.
The DFI module takes measured or calculated data, including engine speed (RPM), throttle position, the temperature of the coolant and intake air, and atmospheric pressure. The processing unit of the module then calculates the optimal amount of fuel to be injected into the engine per cycle based on this information.
The oxygen content of the exhaust gas also plays a role in this calculation as well as airflow. In theory, perfect combustion is achieved by injecting just the right amount of fuel into the engine at precisely the right time, resulting in reduced emissions and optimal engine performance.Sensors are input components that measure real-time information about an aspect of a system or its environment and then send that data to a computer for processing or to another component within the same device if it was manufactured with multiple parts. A sensor can be anything from a thermometer to a motion detector. These devices convert real-world phenomena, such as motion, sound, temperature, into an electrical signal, which can be read by other components within your system. The resulting output can be used to trigger an event or simply as feedback to determine if the system is working correctly at any given moment.
Misfiring and stalling due to the failure of the DFI module sensor is a common problem with the Holden Commodore and the Toyota Lexcen specially designed for Australia. If your Holden Commodore is in the VN-VP-VR-VS-VT-VX-VY category or VG-VU UTE series, you can anticipate a misfiring problem or stalling due to faulty coil packs or a DFI module that has reached the end of its useful life.
If your car is cranking and won's start during ignition, be sure that the plugs, the coil pack, and all wires are in good working condition. Replace worn spark plugs, coils, or broken wires.
If the spark plugs and the ignition coil, other coils are fine and wires are not broken, yet the car won't fire, you can proceed to troubleshoot other sensors, including the direct fire ignition module.More recent cars have a Mass Air Flow Sensor (MAF Sensor), which calculates the air/fuel ratio at different throttle levels. If the MAF sensor is damaged, the engine will only crank but won't start. Any broken or damaged sensor should be replaced.
A DFI module is indeed a computer. It is an electronic device containing multiple microprocessors (CPUs), memory modules, input/output devices, and various other components used to process data. A DFI module is more powerful than a standard computer. Each engine cylinder contains a central processing unit, dedicated memory modules, and more capable input/output devices.
A DFI module allows you to adjust critical parameters that affect your vehicle's performance, such as ignition timing, air-fuel ratio, etc. In most cases, only an authorised service centre or mechanic would have these tools. But with the right hardware wiring and knowledge about how to use this device, you could get access to more features on your car so long as these are supported by the ECU software.
The ECU (or engine control unit) is an integral part of the DFI module. It serves as a bridge between the various sensors, actuators, and other components of the engine. It reads data from each sensor so it can adjust things such as fuel injection timing when needed. In addition, by communicating with other devices in your system, the ECU could disable faulty or problematic parts if necessary to prevent damage to your vehicle.
No, not all cars need a DFI module. The DFI module is a standard component in the 1996 Holden Commodore or its twin model, the Toyota Lexcen. In the Commodores, you will find it below the coil packs and the spark plugs housing. Many modern vehicles have so-called dual or multi-point fuel injection systems in which the ECU controls both the primary and secondary injectors. A standalone or stand-alone DFI module is needed when there are two separate fuel injectors, i.e., injectors that receive their commands directly from the ECU without any input from other sources such as throttle position.
The main difference between oil cooler type and water-cooled type modules is how they are cooled. Both devices do basically the same job of monitoring several engine parameters to produce accurate output. Oil cooler units tend to be physically larger than water-cooled units, but this isn't always an accurate way to differentiate them since many oil cooler modules are actually water-cooled and vice versa. The type of engine you have, a V6 or a V8, is a good indicator of which one would be the best choice for your vehicle. The DFI module will also depend on the series of your Holden Commodore. The Commodore available in Australia is in various series (VN-VP-VR-VS-VT-VX-VY or VG-VU UTE series). Confirm your series before you shop for a replacement. If unsure, consult a mechanic.
You would need both an ECU and DFI module. The latter is usually sold separately from the former, so make sure they match or at least use the same software version (some cars such as Hondas will only accept their own brand). Remember that certain car manufacturers may not offer these parts separately, so check with local service centres first before looking online. You also have the option of buying a pre-assembled device instead of trying to piece together components yourself. This can be rather expensive. You would also need to get the necessary hardware, wiring, and software to support this device.
The average price in Australia for a new Direct Fire Ignition module can range from $500 to $1500, while old second-hand modules are usually available at around $250 to $400. Most are supported with an OEM warranty. You can also buy some aftermarket components on the internet. However, these may or may not be supported by your car's ECU. Check with your mechanic or an authorised service centre first before buying one. The more expensive aftermarket parts tend to have more features than OEM ones though they aren't necessarily better in terms of quality. It is strongly recommended to consult before choosing between an oil or water cooler type. If you choose an oil cooler type and your car has a water cooler type, you will need a new radiator as well since it requires its own cooling system for the oil.
Makers of stand-alone DFI modules say that they offer more accurate data representation over a wider range as compared to the original ECU since their sensors are placed in closer physical proximity to them. This allows you to have more control over your vehicle's performance and even have access to some exclusive features that were only previously available for factory or authorised service centre use. Many users claim that these products also improve fuel economy, prolong engine life by providing better ignition timing and increase horsepower when properly calibrated. Because there is no direct connection between the ECU and injectors, there won't be any conflict when switching between different fuels, including LPG, as is common with multi-point fuel injection systems.
The biggest disadvantage is the price, especially if you need to replace a defective module. The stand-alone parts can also make future repairs difficult or expensive if their software cannot be re-flashed. In some cases, reflashing may also require specific hardware and an external computer instead of a laptop since they tend not to have enough processing power for this task. The reviews by Commodore users of the VN-VP-VR-VS-VT-VX-VY or VG-VU UTE and other related series show that this model can fail to fire or stall abruptly without warning or popping out a unit error code. If you're planning to use your vehicle at the track or for racing purposes, these modules will not be as effective as those used by professional drivers using faster vehicles that go beyond 200 km/h.
You would need to flash the DFI module with a new software version if it fails to function properly or not at all. Manufacturers of stand-alone modules usually do flash programming services after you send them the defective unit for analysis and diagnosis. Most brands offer this service free of charge though turnaround time can vary depending on their current workload, so give them at least 2 weeks before contacting them again.
Many users also prefer to fix their own units by reflashing them themselves using an external computer, laptop, and some free software that can usually be found online. A few hours should be enough for most people even if they have no experience in these types of repairs since it doesn't require any soldering, and pretty much anyone can handle this if they follow the instructions carefully. Issue with your car? Take a look at the Australian Government's Competition and Consumer Commission website for any safety recalls.