Questions tagged [electronic-control-module]
298 questions
23
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1 answer
LTFT and STFT values are off and don't make sense
Car is a 2015 BMW M5 and it has an aftermarket CAI and a catback (slip on) exhaust. No other performance mods or tunes.
About 6-7 months ago, I bought a Kiwi OBD-II reader, simply out of curiosity as I am a computer guy and a geek and was curious…
DerStig
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21
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4 answers
How does the car's ECU detect a misfire?
I was wondering what the specific mechanism used by car ECU's to detect misfires is, or are if there is more than one method.
Robert S. Barnes
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13
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2 answers
Why do we need make-specific cables to read car ECUs?
I find it bizarre that the automotive industry has standardized the use of the OBDII protocol, yet most cars require make-specific cables in order to access the complete set of diagnostics and utilities.
A few examples:
VWs require a VAG-COM…
Zaid
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12
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2 answers
Peculiar Interior Lighting Issue
Recently a friend of mine was driving a VW Fox (not new, I'm not sure what year but it was certainly 5+ years old) home in the dark with the lights on. Strangely, after a minute or two of driving all the interior lights turned off. The headlights,…
Max Goodridge
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11
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3 answers
Car stalls and won't restart, but disconnecting the battery fixes it?
2005 scion tc 5 speed. 106xxx
Yesterday driving home car stalls out on the highway and power steering goes with it. Battery and oil light come on and won't restart immediately. Dash lights still work, headlights etc all work. Cranks over like it…
Volktc
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10
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1 answer
A most intriguing cold-start misfire mystery
I'm trying to help a friend out with a CEL on his 2009 Merc GLK 280.
Hooked it up to an OBD2 reader and retrieved a single code:
P0300 - 'Random/Multiple Cylinder Misfire Detected', via the 'OBD Fusion' app on my iPad.
Here is the P0300 freeze…
Zaid
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9
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3 answers
Shouldn't my post-cat O2 sensors (lambda probes) be reporting varying numbers?
On my 2002 BMW E46 330Ci, I've been getting error codes 202 Lambda regulating limit Bank1 and 203 Lambda regulating limit Bank2. Here's the angry sensor readings from the INPA software:
I understand a number of things could be going wrong here, but…
andrewb
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9
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1 answer
Sharp cornering is turning my Service light on for a second
Citroen C4 2005, Petrol
Very rarely I happen to turn without braking properly and my forward momentum is quite high. In these situations I can feel the strain on my front wheels being very high. What happens occasionally is, my SERVICE light comes…
Иво Недев
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9
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2 answers
Higher than normal fuel consumption - What could be the cause?
My 1997 VW Golf 3 is over-consuming fuel, I use 10 liters for 45km,
My mechanic ask me to change the automatic gear-box because it is not selecting gear above gear 3
I change the automatic gear-box but the issue is still there
I change the plugs…
kossi
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9
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2 answers
Keep Alive Memory (KAM)
What is "Keep Alive Memory" (KAM) and how is it different from RAM?
From what I read over the internet, it is kept alive even after the ignition is OFF, but isn't that what a ROM is supposed to do?
Randy
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8
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3 answers
Can a check engine light reset itself when a scan tool is connected?
I have a Toyota RAV4 2002 4WD.
I was driving to the car wash when suddenly the check engine light come on when I accelerated hard. After the wash, it still was on. I drove home, shut it off, turn it back on, light still on. Went and got my scan…
Major Stuen
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8
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1 answer
Changing from two heated O2 sensors to a single O2 sensor
I'm going to be removing a Motorcraft 2150 carburetor in a 2.8L V6 and swapping it for a Ford CFI (and ECU) from a 3.8L V6. I've just recently pulled everything (ECU, throttle body, sensors, harnesses, etc) from a Mercury Cougar.
When I was removing…
Kevin Evans
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8
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1 answer
Do I have an ECU problem?
My 2001 Cabrio only idles. I had a mass/air error code, however I changed this and had no luck.
I swapped one from a running VW, the other VW ran normally, but mine didn't.
I had the shop read codes: mass/air and transmission and speed sensor. I…
schoolie1
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8
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ECM vs. PCM vs. ECU?
Engine Control Module
Powertrain Control Module
Engine Control Unit
Reading about them online, they seem to be the same thing, computers.
So what are the spcific difference between them? Is the other one any better?
Jomar Sevillejo
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7
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3 answers
Cause of limp mode in Vauxhall Astra which ECU code is relevant?
The engine now runs ok when started cold, but if the weather is very hot or it's started when warm it goes into limp mode, whereby the orange spanner symbol comes on and max acceleration is only 1/3 it should be.
I thought it was caused by oil…
BrianTheTallOne
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