On-Board Diagnostics-II (OBD-II). Questions usually involve scan tools, their use and their compatibility, as well as how to interpret Diagnostic Trouble Codes (DTCs).

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4
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2answers
449 views

VW Golf IV Possible Engine Misfire

I guess I better start with a few details on the car in question: VW Golf IV 20 valve V5 petrol engine (2.3L) ~80k miles on the clock Now the problem, it feels to me as if the car is down on power,...
3
votes
1answer
111 views

What OBDII protocol does a 2014 Mitsubishi Outlander use?

I was trying to help out a friend with an intermittent stalling issue, but the OBD Fusion app could not connect to it via my ELM327 Wi-Fi adapter. The protocol setting was set to "Automatic", which I ...
4
votes
2answers
136 views

Stopping distance of a car

I want to calculate the stopping distance of a car from an OBD2 device. Say, I am driving at 30 kmph and apply my brakes hard. My car will skid and stop at a distance "x" meters from that point. This "...
3
votes
2answers
192 views

BMW E90: Professional Radio (Alpine CD73) USB Adapter won't work

I bought an USB Adapter which emulates a CD Charger. The port wasn't used yet. When I plugged my battery the Radio worked, but I couldn't find the CD charger /USB in my radio source menu. Do I have to ...
7
votes
1answer
106 views

Erratic single fault code: P0420, P0440, P0446. Normal variance, or indicative of something deeper?

Working on diagnosing an evap/emission/fuel system problem on my Toyota 2003 Corolla. More on that in this question. On 3/2, I saw a mechanic use his handheld OBD to read a code P0420. On 3/12, ...
5
votes
1answer
112 views

2005 hyundai elantra error code p0501

So my 05 Hyundai Elantra has the check engine light on. I took it to the store & had them put the code reader on & it comes up with p0501 vehicle speed sensor performance. My question. . is ...
4
votes
1answer
126 views

obtaining Remaining Fuel Level from a 2004 VW Polo (Mk4)

If I have a 2004 VW Polo and this uses a K-Line Bus (I think), how can I retrieve the fuel Level in the tank if the information is not made available as part of one of the standard OBDII PIDs (I think ...
4
votes
1answer
80 views

What is SAE 0x15 Short Term Fuel Trim Bank 1 Sensor 2?

I was taking a look at a neighbor's car, and noticed this PID stuck at 99.22% This is in addition to the regular STFT PID 0x06 which is staying fairly close to zero most of the time. What is this ...
2
votes
1answer
96 views

Car OBD protocol?

I would like to connect OBD2 GPS device in my cars. OBD2 connector support limited OBD protocols. I can't find which protocols present in my cars. So i just want to know what protocol is present in my ...
5
votes
2answers
116 views

Is it possible to access multiple CAN buses through the OBD-II port?

As usual I apologize if this has been asked and answered somewhere. I try to only ask questions if I can't find an answer or a satisfactory answer. From my understanding the OBD-II port on vehicles ...
3
votes
1answer
49 views

Can we determine the Cleaning Requirement of Air Filter Using OBD

Many a times, the dealer guy says that the unclean air filter consumes more fuel as compared to clean. So, my question is, is this really related to air filter? If yes, can we determine the case using ...
3
votes
1answer
123 views

How to calculate Car “Distance Till Empty” without knowing the fuel level

I've Renault Duster RxZ. I would like to calculate the DTE(Distance till Empty) which is based on the "how much fuel the car has" and the "mileage of the car" ? Currently the OBD doesn't return ...
5
votes
1answer
395 views

Is Torque App reliable to read O2 sensor data?

My 2006 Toyota Prius is throwing code P0420 and I used a cheap OBD-II reader with Torque App on Android to check if my O2 sensors are working or not. I tried the maintenance mode to just run the ...
3
votes
1answer
78 views

Calculate current drain from the battery in a drive

Control module voltage is one of the OBD PID. It signifies the car battery voltage. Is there any way to calculate how much current is drawn in a drive (say 7 km from my office to home). The voltage ...
5
votes
1answer
372 views

Difference between fuel pressure and fuel rail pressure

In OBD PID wiki page, there are 2 PIDs listed: Fuel pressure and Fuel rail pressure. Are both of them the same? Can someone please give an elaborate explanation of it - What exactly are they ...
3
votes
1answer
62 views

Engine Temperature from OBD data

Engine Coolant temperature is obtained from OBD. But there is no PID to get engine temperature. Obviously, they are related, rather proportional I guess. But can there be a case where my engine is ...
5
votes
1answer
1k views

OBD 2 Fuel reading says No Data

I wanted to read fuel level from the car and display it on my application. The communication was established using the ELM327 Bluetooth interface dongle. The ELM module replies NO DATA for the code ...
21
votes
2answers
1k views

Difference between OBDII and CAN

What is CAN (controller area network)? What are the differences between an OBD-II protocol and a CAN setup?` How do I use an OBD-II scanner on a vehicle with CAN?
2
votes
2answers
325 views

Formula to calculate emission rates

OBD tells whether I have passed the emission test or not. I want to know the formula by which it calculates the rate of CO, NOx, HC emission from my car and compares it with some set threshold value ...
2
votes
1answer
48 views

Expose Car Hardware information

I am looking for way via which i can access my car information when it is running like speed,acceleration,gear information,oil information,etc . My Car details : Hyundai Verma : Model 2006 , Manual ...
3
votes
2answers
206 views

OBDII ELM 327 Bluetooth adapter - is it reliable? [closed]

I got myself such a bluetooth adapter for my car, because the display on the radio stopped working, and I wanted to see if it will show up any errors. There are even apps for Android that work with ...
11
votes
1answer
100 views

Are there any plans to update OBD-II?

OBD-II is ancient It predates the Porsche 911 GT1, Windows 95 and implementation of the Schengen Agreement. I would have thought that SAE would be working to add more diagnostic coverage for ...
7
votes
1answer
333 views

ATMA on OBDII not Working

I have successfully connected a terminal android app to the obd port of my car. And tried dry run of many at commands, many are working as expected. But ATMA (AT command to Monitor All) is not ...
10
votes
1answer
124 views

Computing Wheel Torque From Engine Torque

It seems possible to obtain engine torque and RPM from a truck CAN bus. I'd like to estimate tractive force at the wheels given these two values. How should I go about computing torque at the wheels? ...
5
votes
2answers
3k views

OBD II power when key not in ignition

I can't get to the OBD connector on my car at the moment. As far as I know the OBD II voltage is active even when the key is in lock. Can anyone confirm this? edit : It's for a product that ...
3
votes
2answers
203 views

Wheel alignment from OBD parameters

Can I calculate wheel alignment from OBD parameters. Car is Hyundai i10, and it doesn't give any Steering Alignment/ Steering Position data. The only method to check the alignment is to let the car ...
4
votes
1answer
142 views

Calculating AFR using injector flow rate and mass air flow

Is injector flow rate = Mass fuel flow? If so then AFR = MAF/Injector flow rate. Can someone please confirm this?
1
vote
1answer
122 views

Auxiliary input status and Auxiliary input / output supported OBD2 PID

I want to know what does Auxiliary input status (PID 1E) and Auxiliary input / output supported (PID 65) OBD2 PID mean. Do they tell me whether my car is in the Aux mode (while I am listening to the ...
6
votes
2answers
77 views

Calculate amount of fuel injected

How do I calculate the amount of fuel injected (both gasoline and diesel cars). I want an instantaneous value. http://www.rceng.com/technical.aspx Websites like these ask for 'Desired Crankshaft Power'...
2
votes
0answers
22 views

Calculated vs absolute engine load [duplicate]

The OBD-II protocol (SAE J1979) has a couple of PID's that relate to engine load: +------+-----+---------------------------------+ | Mode | PID | Description | +------+-----+------...
4
votes
2answers
167 views

Gear ratio from speed and rpm

http://stackoverflow.com/questions/30017271/obdii-determine-gear-given-speed-and-rpm Referring to the above link, one method to find the current gear ratio is to calculate Speed/rpm (The rpm is the ...
6
votes
1answer
38 views

On-Board Diagnostics (OBD) Readiness Monitors

I would like to know how does apps like Torque calculate if my car (Hyundai i10 Era) is 'Not ready' yet? What are the factors (complete list) do one checks to decide? Is there any formula to calculate ...
5
votes
2answers
152 views

How is barometric pressure related to emissions testing?

In the VW emissions cheating scandal, news reports say the following: According to the EPA, "the position of the steering wheel, vehicle speed, the duration of the engine's operation, and barometric ...
4
votes
0answers
306 views

Acceleration problem, but only immediately after stopping

Symptoms: The following applies mainly when accelerating from zero speed at 1st gear in RPM below 2500. Above that RPM range, there is no problem (then acceleration is assisted by turbo-compressor). ...
3
votes
0answers
1k views

Mercedes Atego OBD2 live data codes

I have tried to connect an OBDII ELM327 adapter in Mercedes Atego. Somehow I managed to get it in that OBD2 connector. I can see that my adapter is receiving electricity. These are the PID's that I ...
8
votes
1answer
470 views

Is it possible to auto close the power window of a car using OBD and CAN bus?

I am not an electrical or automobile engineer, so pardon my ignorance. I found this product in the market to auto close power windows for certain brands. How can we send signals to the CAN bus using ...
10
votes
1answer
673 views

How to detect engine/ignition (on/off) status using OBD2?

My device needs to know when a car engine/ignition is started and stopped. Is it possible to get that status using OBD2? If yes, which PID will give me that information? Do I need to write any car-...
1
vote
4answers
83 views

What good is a scan tool?

Other than reporting error codes, is a scan tool useful? Can it help you to tune the car to optimize gas mileage for example or other helpful things?
2
votes
1answer
75 views

CO, NOx, HC plot with AFR Table [closed]

Can someone provide me with a lookup table (reliable of course), or a plot (with exact plot to scale) for CO, NOx, HC emission from a SI engine? If possible, I am also looking for the same with for ...
2
votes
1answer
167 views

Determining active gear from OBD2 for Ford Fiesta

I am trying to to write an app which advises the driver to change gears and do some other driving quality assessments. For this purpose I need to determine the RPM and currently active gear in a ...
9
votes
3answers
220k views

What is the pin or keycode for ELM327 bluetooth OBDII adapter?

The infamous ELM327 OBDII device came without any paper, just a crappy CD with no document related to the device (only some software and drivers thrown on the CD almost randomly). I tried the ...
2
votes
3answers
158 views

Oil pressure and fuel pressure formula

Can someone give me a formula to calculate Oil and Fuel pressure of a car engine? Consider a small passenger car. I have information like Total distance travelled, speed, rpm, MAF, MAP, Intake Air ...
1
vote
1answer
340 views

Error Message from OBD-II (7F 01 11)

I have been extracting OBD-II DATA from UART board (ELM327) on my TOYOTA INNOVA. It responded correctly few weeks before and gave all supported sensor values. But now, for every response, ECU responds ...
2
votes
1answer
137 views

Calculate tyre pressure of a car from OBD parameters

I want to calculate the tyre pressure of a car from OBD parameters. I don't want to take TPMS or any custom PID for this. One of the indirect method is the calculate: ((w_LF + w_RR) - (w_RF + w_LR)) /...
3
votes
1answer
207 views

How can one calculate volumetric efficiency without a MAF sensor?

I am completely new in the field of OBD2 sensor; I am looking for a method (or a formula) to calculate Volumetric Efficiency of: Diesel Car Petrol Car which do not have a MAF sensor. Can anyone ...
2
votes
1answer
576 views

Getting MIL on a Dodge Grand Caravan 2012 without an OBD device

I have a dodge grand caravan 2012 and yesterday, the check engine light went on. I know there's usually a way to get the error codes without an OBD device... I was able to do this on my old caravan ...
0
votes
1answer
109 views

Calculate car battery life using OBD parameters

I want to calculate the battery life of a car based upon OBD2 parameters like engine load, distance traveled, Control Module voltage etc. Can anyone please guide me as to how to do this? If ...
1
vote
2answers
59 views

linking a phone to a car via OBD-II and Bluetooth: Automatic (1st gen) in Europe [closed]

I am relocating to Europe soon, and I'm pretty sure my new car would have OBD-II. Why is Automatic adamant their current product is for the US only? Is it a regulatory issue, or something technical ...
4
votes
1answer
105 views

OBD-II reader has power but shows nothing

My check engine light is on, the car ran out of battery and after jumping it, it is running kind of poorly, idling rough, etc. I plugged in the OBD-II scanner/reader, and it "has power" (green ...
2
votes
1answer
51 views

Detect engine stumble or hesitation

I want to know if I can detect my engine is having hesitation/stumble problem from an OBD. I mean not from any fault codes, but from the parameters obtained from the OBD. e.g. calculate the obtained ...