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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8
votes
4answers
691 views

Is control module voltage and battery voltage the same?

Is the Control Module Voltage (from OBD Mode 01 PID 42) and battery voltage the same? If not, what is the relation between them? Why is the max value of Control Module Voltage (from OBD Mode 01 PID ...
10
votes
1answer
492 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 ...
8
votes
1answer
294 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 ...
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 ...
2
votes
1answer
71 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
139 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 ...
2
votes
3answers
128 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 ...
2
votes
1answer
114 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
2answers
205 views

Can a universal catalytic converter be legally fitted to my Prius in California?

My 2006 Toyota Prius with 280k miles is throwing the P0420 code, which means that it (probably) needs a new catalytic converter. I live in California, which makes life much more difficult to replace a ...
2
votes
1answer
298 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
86 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 ...
4
votes
1answer
101 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 ...
4
votes
2answers
2k 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 ...
2
votes
1answer
48 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 ...
9
votes
2answers
138 views

Received frames from vehicles with multiple ECU chips

I'm not generally a 'car person', so hopefully I can explain this well enough to get some help here: When sending messages to an OBD-II device, I receive one response in most cars I've tested. ...
2
votes
2answers
228 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 ...
3
votes
0answers
78 views

BMW E90: Coming Home automatically on darkness

I have a BMW E90 ( pre- facelift ) with light package . Currently my car is set so that the " Coming Home " function can by pressing the headlight flasher is switched off, press at ignition . My ...
4
votes
1answer
54 views

Android App for ELM 327 that allows to reset codes for Cadillac CTS

On my Cadillac I get engine light to come up because I have changed my petrol cap and sensor is malfunctioning. I got myself wifi ELM 327 OBD-2 reader, and by using my laptop I managed to get RPM of ...
1
vote
1answer
50 views

How can I tell if I would benefit from higher octane fuel?

Given the number of variables involved in whether an engine will knock on a given fuel in a given environment: How can an end user determine whether the engine is retarding timing due to fuel octane? ...
4
votes
2answers
224 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 ...
2
votes
1answer
326 views

Read error codes without scanner on Pontiac G6

I've read certain vehicles may begin flashing their check engine light if one bridges the diagnostic plug correctly with some wire before starting the vehicle. How does one do this for a Pontiac G6? ...
2
votes
1answer
56 views

Do car manufacturers provide specific make/model/year information for each diagnostic-trouble-code?

Recently my car's check-engine light came on, I used a car OBDII port code reader to get the diagnostic-trouble-code (DTC) and then I googled what the DTC meant. I noticed that lots of the websites ...
1
vote
1answer
1k views

OBD2 to USB Cable for Windows 10

One could put an argument that this question is about software and not mechanics, however now-days everything is computerized (including cars and their diagnostic tools) so I believe this question ...
3
votes
1answer
54 views

Is OBD-II a universal standard?

I'm following this guide: http://www.instructables.com/id/How-to-fix-your-check-engine-light/?ALLSTEPS According to this website an OBD-II reader will work with my 53 Vauxall Zafira, but I want to be ...
2
votes
2answers
455 views

Interpreting ABS/DSC fault code

I have an ABS, DSC and handbrake warning light (the latter telling me it's likely from one of the rear wheels) on my BMW E46 320d from 2001. The warning used to be intermittent (it would go away, then ...
1
vote
1answer
42 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?
1
vote
2answers
281 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 ...
3
votes
1answer
182 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 ...
3
votes
1answer
549 views

Cleaning the gas cap to rule out that tightness is the cause of the “check engine” light

The gas cap on my 2003 Pontiac Vibe used to make a slight sound of "pssstt..", the sound of some air either entering or exiting from the tank as I was opening the cap. Two months ago, the gas cap ...
2
votes
1answer
140 views

What OBD II protocol does the 2004 Ford Explorer?

Does the 2004 Explorer use J1850 or some other protocol ? Is there a way to extract codes by jumpering pins on the OBD connector ? Thanks
5
votes
2answers
133 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 ...
2
votes
1answer
31 views

ODB2 Fuel Level 2004 Chrysler Town & Country

I am wondering if anyone knows if a 2004 Chrysler Town & Country supports Fuel Level over ODB2. I have been unable to find a list of which vehicles do/don't support this. Thanks.
2
votes
1answer
2k views

Error MIL: off Spark ignition

I checked my OBD2 sensor and it shows on DTC that message. Along with P0171 system too lean on my Mazda 3. I put in an injen intake and that was 3 years ago. The check engine light came on 3 months ...
2
votes
1answer
98 views

what does the highend OBD2 scanner offer?

I just want to clear some misconceptions that i have about the obd2 scanning tools : Is the difference between the high/low-end scanners is the software only? Do the highend use more connection ...
1
vote
1answer
252 views

Maruti Suzuki Swift Check Engine Light On And Engine Coolant Temperature Needle stay at 'C'

My Swift VXI has developed a condition. I have started to see the check-engine light on and the Engine Coolant Temperature Needle stays at 'C' after starting the engine. Engine gives a growling sound. ...
4
votes
1answer
153 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 ...
4
votes
0answers
227 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). ...
4
votes
0answers
38 views

Integrating Fast OBD Readings and GPS

I'm working on a project to look at fuel consumption on different roads and I need the OBD reader to log the GPS coordinates every time it takes a reading. I'm looking at instantaneous fuel ...
1
vote
0answers
47 views

Do any generic OBD tools provide re-keying OBD Key? [closed]

It seems the rekeying mechanisms use OBD II. Here is an example of one. Do any generic OBD II Diagnostic and Key Code Clearing tools support this rekeying functionality via OBD Key? Preferably one ...
17
votes
3answers
7k views

Can a vehicle be harmed with bad inputs via an OBD-2 port?

I bought a cheap (sub $10) ELM 327 Bluetooth clone OBD-2 diagnostic adapter on a local "ebay-style" market where the seller specializes in car diagnostics and has several thousand positive reviews ...
1
vote
2answers
57 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
0answers
160 views

Unable to connect OBD2 scan tool

Cheerz, I have purchased recently OBD2 scan tool(Autel MaxiScan MS300) which supports ISO9141. My car (Mitsubishi Lancer GLX 1.3 1999) seems like ODB2 compatible using ISO9141-2 protocol for ...
4
votes
2answers
378 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 ...
2
votes
2answers
881 views

Live scan tool for OBD 1.5 GM transitional?

1995 S-10 Blazer 4.3L Vortec V6 (vin W) with Powertrain Control Module (PCM) 1995 was the OBD transitional year for GM. The PCM itself is OBDI, but the interface connector has the 16-pin D-style ...
2
votes
1answer
1k 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 ...
1
vote
1answer
615 views

Read vehicle speed data in real time

I need to read vehicle speed (velocity) data in real time for my research project. How can I achieve that? What HW and SW do I need for it? I guess it can be read from CAN bus via OBD2 interface? I ...
4
votes
2answers
230 views

Replacing Cam Position Sensor; any gotchas?

I have a 2007 Nissan Murano. My Check Engine light is telling me that the cam position sensor (bank 1) is bad. I've located the sensors, and they are both readily available and easy to get to. Is ...
-1
votes
1answer
183 views

How to extract data from ODBII?

I bought a EvZ Mini Interface Works on Android Torque Bluetooth Obd2/obdii Car Diagnostic Scanner (Mini), a PWOW® WIFI Wireless OBD2, OBDII Car Auto Diagnostic Scanner Adapter Reader, ELM327 for ...
0
votes
1answer
377 views

CAN Bus action list

I have an ELM327 Bluetooth, which I'm linking to ubuntu powered PC. My end goal is to install a raspberry pi into the car and have it automate things like automatically opening the roof and locking ...
7
votes
3answers
644 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 ...