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26 votes
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How does the car's ECU detect a misfire?

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 ...
cdunn's user avatar
  • 9,296
15 votes
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Sharp cornering is turning my Service light on for a second

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 ...
Steve Matthews's user avatar
12 votes

How does the car's ECU detect a misfire?

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 ...
Autistic's user avatar
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8 votes
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Is there a way to use a PC as an ECU for testing CANBUS Sniffer devices?

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 ...
cdunn's user avatar
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8 votes
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Can a car operate without a catalytic converter?

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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes
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Will disconnecting battery lead to remaps being reset?

No, it shouldn't. During a remap, there are tables which the ECU reads to know what/when/how fueling and other events should occur. This is in non-volatile memory. There are other parts of the ECU ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes

Do automakers ECU-tune their motors to make new models and versions?

It's absolutely true that auto manufacturers tune engines to give different performance levels. I had a BMW 530d and discovered it was the same engine as the 535d, the only difference was the ...
GdD's user avatar
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6 votes

How does the car's ECU detect a misfire?

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 (...
HandyHowie's user avatar
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6 votes
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Bike currently running rich due to aftermarket exhaust, will adding an aftermarket air filter without any ecu work fix it

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 ...
DucatiKiller's user avatar
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6 votes
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Tapping into the on-board computer

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 ...
DustinDavis's user avatar
6 votes
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Cannot Access ABS-control-unit with ODB2-adapter

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 ...
Zaid's user avatar
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6 votes

1986 truck running rough and intermittent fault codes. Faulty capacitor?

The one in your image seems to have some burn marks so I'd be suspicious about it. Get yourself an LCR component tester for about €$£10. This will allow you to remove each capacitor, check its ...
Transistor's user avatar
5 votes

Cause of limp mode in Vauxhall Astra which ECU code is relevant?

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 ...
DucatiKiller's user avatar
  • 32.9k
5 votes

Tapping into the on-board computer

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 ...
tallpaul's user avatar
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5 votes
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Need urgent help - car cut out and instruments frozen and will not start

I found the problem. I purchased breakdown cover and called the AA out on Sunday afternoon. They were very fast and the guy was incredibly helpful. He said that a fuse had blown, and checked the fuses....
George's user avatar
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5 votes

Shouldn't my post-cat O2 sensors (lambda probes) be reporting varying numbers?

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 ...
Zaid's user avatar
  • 39.2k
5 votes

Can I replace my ignition coil with a ECU?

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 ...
Steve Matthews's user avatar
5 votes
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Why buy an ECU with the highest version alphabet?

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 ...
enderw88's user avatar
  • 306
5 votes

Can't detect Proton GEN2 ECU

When a scantool is unable to connect to a vehicles ECU: Make sure you have power to the OBDII connector under the dash. (Since the adapter lights up, it means you have power) Try connecting to a ...
Milison's user avatar
  • 634
5 votes
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Considerations for a successful VW 2004 Jetta 2.0L engine swap in place of a 1.6L engine

It would help if we had the engine codes and the two ecu types (EDC15/16, Med7/9 ect) and the fault codes that are present but here goes: It sounds like the engine was swapped complete with the ...
Newbie Noob's user avatar
  • 2,781
5 votes

When doing an engine swap , do you have to have a matching ecu

GM engine management software (from your old Impala ECM) is not going to be able to run a Honda engine. If you managed to flash the Honda software onto your GM ECM, you'd likely brick the device. A ...
3Dave's user avatar
  • 3,149
4 votes

Honda Brio AC Problem

I don't know about this car specifically but I've had a whole lot of time working as an air conditioning (AC) engineer at a Detroit based Original Equipment Manufacturer (OEM) The body control module ...
zipzit's user avatar
  • 6,559
4 votes

What voltage does the ECU need?

If you're talking about a regular 12V battery vehicle, then the ECU is likely to work from 7V until 14V with no problem. That's the usual requirement for this kind of component.
PDuarte's user avatar
  • 217
4 votes

How to calculate fuel consumption and CO2 emission on flex fuel cars using OBDII data?

"Flex Fuel" isn't an issue (I assume you mean E85 and similar) if you use injector duty cycle as the basis of your calculations. Total injector "on" time gives you fuel consumption, regardless of the ...
SteveRacer's user avatar
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4 votes
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Relation of VIN of a car with emission norms of a country it is sold

Cars are manufactured to meet the emission standards of the country it is intended to be sold in. If the car was manufactured in Canada with the intent to be sold in India, it will be designed to meet ...
tlhIngan's user avatar
  • 12.2k
4 votes

Gonna remove my Cat...issues with the ECU 😳?

When the ECU is in closed loop operation is uses the reading obtained from the lambda probe to adjust how much fuel is required by the engine. In order for this to work it has to measure the exhaust ...
Steve Matthews's user avatar
4 votes

How to remove pin from Subaru ECU plug

At the end of each wire is a terminal. In order for the terminal to stay in place while the male pin of the opposing connector is pressed in, there is a small locking tab on the terminal (arrow). ...
CharlieRB's user avatar
  • 9,015
4 votes
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Why modern car networks are known as "unsafe"?

In an ideal world, you are right, the entertainment system should be entirely separate from engine management, navigation, locks, immobiliser etc. But the world isn't ideal, and many decisions are ...
Rory Alsop's user avatar
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4 votes
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Siemens sim2k-34vr ecu parametrs and service ids

I found its PIDS is under MODE 0x21 and PID 0x01, I hope it helps to other peoples.
Amin Rezaie's user avatar
4 votes
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How are new cars (with HO2Ss) affected by cold starts?

It's true that heated O2 sensors shorten the time the engine is in open loop. So the whole "wasting gas thing" while you wait for the engine to warm up isn't as big an issue. But there are many other ...
user9181's user avatar
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