Questions tagged [obd-ii]

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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6
votes
1answer
9k views

Read steering angle data in real time

I need to read vehicle steering angle (front wheel angle) data in real time for a research project that I am involved in. How can I achieve that? What HW and SW do I need for it? So far I can think ...
6
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2answers
2k views

Writing CAN Messages

I want to know what should I write with the CAN ID to send it to ECU. I am using ELM327 and Raspberry Pi with all connections to OBD-II. Initially for sending general PIDs to the ECU through ELM327 ...
21
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3answers
1k views

What are good features to look for in an OBD-II reader

I recently took my car in for the engine light. It turned out to be a minor problem (crack in gas cap let water in). It would be nice to have a low-cost OBD-II reader to be able to find out for ...
8
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3answers
4k views

Calculating MPG from MAP sensor (or converting MAP data to MAF data)

My 2002 Honda Accord V6 has a Manifold Absolute Pressure sensor (MAP). I understand that this sensor gives out information in pressure units (psi or equivalent). After doing a bit of research, I ...
5
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1answer
39k views

OBD II Scanner refuses to communicate with the vehicle!

All the fuses check out All the relays check out Could I have a faulty ignition switch? Or an open somewhere? How do I go about troubleshooting this? It cycles through all the protocols, finds ...
2
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0answers
2k views

Fuel Consumption and other Fuel related data from basic OBD-II parameters [duplicate]

I want to know how can i obtain the values of Fuel Consumption, Fuel Economy and other fuel related information from basic OBD-II parameters like Vehicle Speed, RPM, TPS etc. I have noticed that not ...
9
votes
2answers
976 views

How do I go about troubleshooting DTC codes?

When the check engine light (CEL) comes on, there is usually a diagnostic trouble code (DTC) that can be read from the OBD-II (onboard diagnostic) port on modern codes. How do I go about using the ...
4
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1answer
524 views

Quick Oil Change place overfilled my BMW Z3

Just got this car, a BMW Z3 3.0 from a Tampa dealer and have not even had it 10 days and Check Engine Light came on. I wanted to get the oil changed to full synthetic just in case it wasn't and ...
1
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2answers
1k views

OBD-II Fuel type and level of Monofuel Cars

I'm making an application like Torque and i have some issues with commands of Fuel Type and Fuel level with cars that use only one type of fuel like, Only Diesel or only gasoline. With car Bifuel ...
0
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1answer
5k views

How can I calculate MPG using an OBD-II Device

OBD-II provide following readings Mass Air Flow (PID 0166) Fuel–Air commanded equivalence ratio (0144) Can these be used to calculate the actual fuel consumed? Is the output correct?
30
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2answers
45k 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?
16
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1answer
3k views

How do I find the correct pins in a CAN-BUS connector?

This question might be too technical for this forum, but I'll give it a go. I have a 2012 BMW R1200R motorcycle with CAN-BUS. I'd like to make an Arduino interface to the connector on the bike, but I ...
6
votes
2answers
59k 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 will be ...
12
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2answers
3k views

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 ...
6
votes
2answers
8k views

Any open-source OBD scanner analysis tools?

I've been having some weird problems with my '06 Pontiac G6, and finally broke down and bought a Bosch code scanner to see if the DTCs could tell me anything... they didn't. This scanner has the ...
6
votes
1answer
9k 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 ...
6
votes
2answers
928 views

control car's steering angle from linux

I'm trying to send steering wheel angle commands to my car. It's a fairly recent car (Renault Espace IV). I'm using an OBD2 port to access it, and I also have a ShieldCan. I managed to read data from ...
6
votes
3answers
1k views

Tapping into the on-board computer

I'm thinking of replacing my car's radio panel with a custom built Raspberry Pi device, something like this device. However, it's usefulness would be much larger, if I could get information from the ...
6
votes
1answer
1k views

OBD2 and CAN-bus

Do all vehicles with OBD2 have a CAN-bus? Otherwise, what are the alternative buses used? Are there special versions of the buses for trucks and school-buses than for cars/suv/vans?
6
votes
2answers
3k 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 ...
5
votes
1answer
636 views

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

Here is the thing: I'm trying to estimate the fuel consumption of cars using OBDII data. It's quite simple if we can treat each fuel and its stoichiometric air fuel ratio separately, but when it turns ...
4
votes
2answers
18k views

What does it take to program a used ECU?

I own a Mazda MPV 2000 with a faulty ECU. The vehicle has an immobilizer. It will not start with the former ECU. It floods the engine with fuel. After extensive diagnostics on the vehicle and the ...
3
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2answers
17k views

Does disconnecting the battery reset on-board memory?

Will disconnecting my car battery reset the on-board memory or do I have to manually erase it to remove error codes? I ask because I have a faulty electrical system that throws gas leak errors and I ...
1
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1answer
776 views

Can i control the brakes of a car by the OBD II Interface?

I'm doing a senior project about automating the braking system in cars and make it smarter
1
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2answers
766 views

Calculating fuel flow rate through obd || sensor not supporting 015E and 0110 commands

I have been working on a project where i want to calulate fuel flow rate using data from the obd2 sensor. The car on which i was testing didn't support the pid 015E which is for fuel flow rate. Then i ...
1
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1answer
2k views

What is the drive cycle for OBD-II equipped GM vehicles?

As the title states, what do I have to do to get through the drive cycle for OBD-II equipped GM vehicles?
0
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1answer
2k 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 ...
9
votes
3answers
56k views

Do fault codes get recorded with a time stamp into a log with a history of DTCs?

Just scanned my vehicle for the first time to check out the code for a Check Engine Light. I grew curious if these fault codes get logged somewhere with a date and time stamp of some kind at the time ...
7
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1answer
2k 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
2answers
2k views

Reading OBD2 too fast

I'm writing a software to make a telemetry application for my 2001 VW Golf mk4 reading parameters from OBD2 using an ELM327 compatible cable. I succeeded so far. The problem that I have now, is that ...
5
votes
1answer
3k views

Oxygen sensor PID for 2004 Toyota Camry 4-cyl

My 2004 Toyota Camry with 170k miles is pulling a P0420 code, which I've read can be due to a bad catalytic converter or O2 sensors. I have an OBD-II tool with the DashCommand app on my iPhone. ...
4
votes
1answer
423 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 ...
4
votes
1answer
1k 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
575 views

OBD or CAN - what's mandatory (EU and US)

First of all, I've already tried to do my research and tried to get all the info I'm asking for myself (which obviously didn't work). I want to know if CAN or OBD(-II) are in fact mandatory in the US ...
3
votes
3answers
9k views

What should I do about PS0128 “Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)” error code?

I have a Mazda 6 and recently purchased the OBD 2 module and saw the check engine light with the PS0128 Error Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). I ...
3
votes
1answer
1k 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 help ...
3
votes
3answers
90 views

Evap System Leak, Repair and Clear Codes to Pass USA State Emission Inspection?

I'm aware of two related issues here Does Check Engine Light Clear Itself... I need the correct 2010 ... drive cycle steps to clear a “Permanent ” P0456 code I've just completed a particularly nasty ...
3
votes
2answers
3k views

Catalytic converter readiness monitor never sets

I Reset the computer in my 1998 Chevy Astro, but even after driving around for a few days and putting it through the GM drive cycle, the OBDII reader is saying that the CAT monitor is not ready. I ...
3
votes
1answer
2k views

How to Reverse engineer the manufacturer specific protocol on OBD2 for acquiring enhanced vehicle data

I understand that generic OBD2 readers gives a limited set of vehicle data (PIDs). Enhanced set of vehicle data could be aquired via the protocols which is car manufacturer specific (not published). ...
2
votes
1answer
856 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)) /...
2
votes
1answer
136 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 ...
1
vote
2answers
2k views

ECU signals to CAN bus

What methods or ideas are out there that can match or change an SR20det ECU's signals or codes in order for a newer CAN bus system to read, for example, the power steering to work as well as the ...
1
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0answers
366 views

Cars with single fuel type how retrieve tank level to dashboard?

I see that BiFuel cars had fuel level and type readable from ECU by using pid 0151 and 012F. Cars with monofuel don't have this pids sensors, so how the dashboard retrive the fuel level? Maybe the ...
1
vote
3answers
500 views

Is obd code P0133 anything to worry about?

The day before I got this obd code I changed clutch and gear box oil. 15 minutes before I got this code one of my brakes pads completely wore out. I read a bit about the code and I guess they are not ...
1
vote
0answers
370 views

Does limiting the number of PIDs on an OBDII Live Scan increase the sampling rate?

I was messing around with the live scan settings on my BlueDriver OBDII scanner and I checked another PID box and got this message: To provide the best quality of data, we recommend logging no more ...
1
vote
2answers
76 views

OBDII Code P0348: Camshaft Position Sensor A

Last night, the check engine light went on on my 2006 Toyota Tacoma with 152K miles. When I got home, I plugged in my OBDII code reader and got Does this mean I just need to replace one of my ...
1
vote
1answer
2k views

Reading CAN messages through UART to OBD-II Board and MATLAB Toolbox

I want to read/write CAN messages. I have MATLAB in my laptop which has a Vehicle Network Toolbox which supports reading/writing CAN messages. I have my hardware OBD-II to UART board, FTDI and OBD-ii ...
0
votes
1answer
86 views

Where is the injector circuit on a 2007 Toyota Yaris?

I have the PO201 error code which appears randomly every 30Km to 50 Km. The issue sounds possible as the car ran 2000Km with a damaged spark in cylinder 1 before repair. However, they are no circuits ...