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23

This comes directly from this web site: http://www.obdii.com/articles/Onboard_Diagnostics_Demystified.html What it says, is that early OBD-II systems could not detect misfires, but since then a few variations on the theme have been implemented. The basic idea is that if a cylinder fires, it gives a kick to the crankshaft causing a slight variation in crank ...


16

It could be that you are cornering so hard that you're pushing the oil in the sump to one side, away from the pickup pipe. This temporarily means you're oil pump is sucking up air and you are starving your engine of oil. Competition cars are equipped with with baffled sumps or dry sump systems to prevent this happening. In a standard road car, this type ...


15

I think I have an answer But bear in mind that this is my assessment with the limited information at my disposal. I'll walk through my reasoning here. If someone finds a flaw in my logic then I'm all ears. Here is a summary of your data +-------------+-------+-------+-------+-------+ | Condition | LTFT1 | LTFT2 | STFT1 | STFT2 | +-------------+-------+-...


12

Engine misfire can also be detected by looking at the coil voltage just after the plug is fired. When the fuel/air mixture actually ignites there are lots of ions and radicals floating around. This provides an easier path for electricity from the coil. If the mixture does not ignite for any reason the resistance is extremely high. An observant auto tech ...


8

From my personal experience with this particular subject you have many variables that come into play. My shop specializes in computer systems on some of the newer vehicles (Mostly Japanese), but we do work on anything given the chance. ECM, PCM, and ECU are generally manufacturer specific. I usually see ECU when referring to Asian vehicle companies. Chrysler ...


8

Sadly you are not going to be able to do what you want simply connecting CAN-H and CAN-L to a serial port. Here is a pointer to the physical interface layer for CANBUS. CANBUS Physical layer ISO 11898 What you will find is that while CAN is a "serial bus" that just means that the data is transmitted one bit at a time. It does not mean that it can be ...


8

Most vehicles which are OBD-II compliant (newer vehicles are a little different) use just the O2 sensors located before the cat to adjust the air/fuel ratios. The in-cat or after-cat O2 sensors are just used to check the efficiency of the cat itself. Therefore, in most modern vehicles a car can run just fine without a cat. Please note, this is not to say ...


7

It might seem easy to integrate a sensor that detects the opening/closing of a mechanical thermostat's pintle (LVDT, for example) but here are some challenges which would need to be addressed: Cost vs Benefit Is a "smart" thermostat really worth the extra hassle and money when its dumb counterpart has the following to offer? : it's already cost-effective ...


7

The injector has a plunger/pintle which is controlled by an electromagnet. The humming you heard is from that. The plunger/pintle has a spring which pushes back against the electromagnet so when the power is shut off, the plunger will close and stop the flow of fuel. This causes the hum. Here is an example of how an injector is built: When the power is ...


7

How do I pull error codes from my Kawasaki motorcycle? Here are the instructions to pull error codes from your 2001 or later Kawasaki street motorcycle. Step 1 Pull off your seat and near the battery negative terminal there will be a self diagnosis lead coming out of a connector. The wire is yellow. It looks like this. Step 2 Get a wire, one with ...


6

VTEC - Variable Timing and Lift Electronic Control VTEC requires the ability to understand the state of the environment and motor in order to change the valve timing. Various sensors from oxygen, engine rpm, barometric pressure, engine temperature, air temperature, oil pressure, throttle position effect the the various timing events of a VTEC engine. ...


6

There are 6 pins in the OBD-II connector which the manufacturers can use at their discretion. In modern vehicles there are usually 2 or more communication buses. Only one bus is for engine and emissions, which is connected to the standard diagnostic pins on the OBD-II connector. The manufacturer typically connects another bus to the OBD-II connector with ...


6

The federal test procedures for vehicle emission certification(FTP) is run on a dynamometer. It starts with the vehicle at an exact temperature and barometric pressure and humidity. It is run in a lab that has carefully controlled exact air conditions that are maintained throughout the test. The vehicle is kept is stored at the test temperature for hours ...


6

You can determine the gear by comparing the engine RPM and the vehicle speed. Most cars that have a shift light though do not actually know what gear they are in, they use engine RPM, engine load and throttle position. A near stall could be determined by looking at engine load and RPM. Low RPM and high load will give it away.


6

You can't necessarily re-program an ECU that is stock from factory. There are a few aftermarket ECUs that you can buy though. On that particular vehicle it won't make too much difference. You can tune the crap out of it, but it won't increase torque or horsepower by much. In general from my experience the only time people tune stock or naturally ...


6

Yes, it is possible Albeit with some trade-offs. A modern-day road car is an amalgamation of several sub-systems, and electronics usually have an important role to play in them. The nice thing is that many of these sub-systems were present long before modern-day electronics became commonplace: Engine The heart of the beast remains mechanical to this day, ...


6

Variations in current drawn by the "high-tension" (HT) coils can also identify misfires to the engine ECU. This is one reference that I found to back this up AutoTap: Analyzing Ignition Misfires (archive)


6

If anything, your bike should be running lean Thoughts You put an aftermarket non-restrictive exhaust on your MV, that increases the flow of gasses which requires more fuel to compensate for the additional flow. So, the idea that your bike is running rich doesn't really resonate. It certainly can be and if it is it could be indicative of another issue ...


6

You cannot easily "tap" into any ECU/PCM. Depending on what year your vehicle is, it could be a simple set of analog gauges which you could tap into the signal line, but you'll need to do some hardware design to convert the signals to usable data. If it's a newer vehicle, you'll have to deal with the canbus protocol and that will be very difficult. Your ...


5

There is no need to reprogram the ECU This is for a couple of reasons: The engine barely feels a difference Contrary to what the name implies, a "free-flowing" intake impacts the pressure at the valve inlet and not the volume of fresh inlet air per cycle. Here are the numbers to back it up: K&N provide detailed test data for the Yamaha R15, which ...


5

Root Cause: probably a couple of things Sadly, I feel that there isn't enough data here to uncover the smoking gun, but I have realized some things upon reflection that can indicate what is probably wrong with the vehicle: Question 1 If the front lambda sensor voltage is indicating rich, why is the fuel trim positive (indicating that the injector pulse-...


5

I have replaced he old ECU ( SIRIUS 32N ) with another one ( SIRIUS 32 ) which is used before, the car has not started the first two tries but have started normally the third time, the immobilizer light have not been blinking which means there is no immobilizer problem and this means either the ECU is already decoded ( it is supposed to not be decoded ...


5

KAM remains powered when the ignition is off due to the fact it receives power from the battery. It is the same as RAM in the sense that it is a volatile form of memory and will lose its data if power is lost, this is what makes it different to ROM which is non-volatile and does not require power to store data. The KAM stores details about vehicle usage ...


5

If your car has a OBD2/ODBII port then it is achievable. I'd imaging the simplest way would be to use a ELM327 type cable or even a bluetooth adapter to provide the interface between the pi and the car.


5

Essentially you have put 10 milliliters of oil in your gastank I have done this before with more oil than that on accident into my truck. My solution was to fill the tank to the top and dilute it as much as possible. This worked fine for me and I had no ill effects that I am aware of. The truck passed emissions after that and I have had no maintenance ...


5

Here's how to decipher INPA lambdaintegrator Short-term fuel trim. Both banks have a short-term correction of 28%. This should settle down to 0% fairly quickly, so the fact that it stays red indicates that it is attempting to apply the maximum possible correction for a lean condition (and failing to bring it within spec). adaption value additiv This is ...


5

To my knowledge, access to the ABS module will not be possible through a generic OBDII adapter. The most commonly available option for VW's of this era is a VAG-COM cable with RossTech software on a laptop.


5

There are a number of ways to go solid-state ignition and there are a few open source projects that allow you to build your own ECU and loom and utilize an ignition system from something else. One system that instantly springs to mind is MegaSquirt which is a programmable ECU project that uses Ford EDIS parts. Depending on the engine configuration you have ...


5

As a general rule, you should buy the part number specified for your car. Later (higher version alphabet) may not be compatible. If it is compatible it is unlikely you will notice a difference since the ECU changes need to be small enough not to effect any legal compliance they have been certified to meet. In your specific case the changes could have been ...


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