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11

The computers in a car are constantly monitoring the operating conditions and sensors that are in the car. When a test fails or something goes out of a pre specified range a DTC is set. The biggest misconception about a DTC is that it tells you what to replace, it does not. A DTC tells you what test failed or what parameter went out of range. This ...


9

It really depends on the implementation of OBD2. What my 1997 Subaru logs (virtually nothing) compared to a 2015 Chevy Cruise are entirely different things. However, in most cases, a Diagnostic Trouble Code (DTC) is logged with a freeze frame, which is a complete store of all Parameter ID's (PIDS). These parameters cover everything from RPM, vehicle speed,...


7

We found at least two issues The air filter housing wasn't forming a proper seal with the MAF sensor This engine boasts a quirky design where the MAF sensor sits at the back of the engine. The air filter housing seal is in the middle of this first picture, MAF sensor in the second picture (stills were taken from this video). Whoever had installed it didn'...


6

It's just in front of the front passenger side door, under the dashboard. It might be stuck down behind the carpet a ways.


6

The CEL trigger implementation will vary across vehicles, but here are a few for you to try out. They should not have any negative effect in the long-term on the vehicle: P010x - unplug MAF sensor P030x - unplug a spark plug wire/coil (unplugging the corresponding injector is recommended) P0420/P0430 - unplug the O2 sensor after the catalytic converter


6

@JPhi1618 answer is good. I would just add a few more, You can unplug the EGR Valve electrical connector, no harm to engine. Pull out a coil pack or coil wire.


6

Start unplugging stuff. The engine will normally run with a lot of the sensors unplugged, but the check engine light will come on quickly. Some easy to reach ones: Mass Air Flow (MAF), Oxygen sensors, sometimes the throttle position indicator (on the throttle body). If you can unplug the power to the secondary air injection pump, it will cause a fun ...


6

Sourceforge has this scantool.net open source application. I have used it on my laptop with a USB to ODBII converter on various vehicles. You can google "USB to ODBII" and get multiple hits to procure this cable converter. Here is the LINK to the software download. It also comes with source code. Good luck.


5

There's a lot of work going on in this space, so the answer is "Yes, Of course!" Here is a Python project: http://www.obdtester.com/pyobd This looks like an interesting way to get data from the car, but doesn't seem to really be about trouble codes or diagnostics: http://openxcplatform.com/getting-started/index.html This looks very outdated, but maybe ...


5

To add to the list, run the engine without the fuel filler cap on.


5

Oh wow, there's definitely something funky going on with the electrical system. With regards to the P0563 and P0621, have you tried getting a live reading of the voltage from your scan tool or a multimeter when the car is running? My advice - get a decent automotive electrician on the case. Your run of the mill mechanic isn't the right person for the job


5

If you're worried about the car passing emissions testing, seeing the check engine light go off is a good sign. Where I live, you can't be failed because the light used to be on. The status of the code (often showing up as a check engine light) depends on the computer in the car. Obviously, if the light is on, the code is active. Quite often, though, the ...


4

The Air/Fuel Ratio (A/F) sensor 1 is installed in the exhaust system and detects oxygen content in the exhaust gas. The A/F sensor transmits output voltage to the Engine Control Module (ECM). A heater for the sensor element is embedded in the A/F sensor (sensor 1). If the A/F sensor (sensor 1) voltage is low, the air/fuel ratio is lean, and the ECM uses A/F ...


4

If you remove the passenger side foot kick panel covering the ECU you will see it there. On the 97 it is the blue 2 pin plug.


4

First of all, no worries on the bad English side of things ... even those of us who speak it have issues sometimes! '-) As to your issue(s) ... the first thing I do when I've encountered a large number of codes as you've gotten is clear the computer, then rerun the engine to see which codes persist. This gets you a lot closer to the root cause of the issue. ...


4

If the condition that caused it to come on is a minor fault, and stops occurring, then yes, it will clear itself. If the condition indicates a larger problem, then it will stay on until cleared manually. A good example of a condition that will clear itself, is low brake fluid. I experienced this myself when I would only have the light come on when ...


4

There are two kinds of fault codes; single trip and two trip. A single trip fault code is generally a major failure like a severe misfire. This will illuminate the check engine light immediately upon detection. A two trip fault code has to be verified on two trips. The first trip sets a pending code without illuminating the light. If the fault is ...


4

Double check your code, Mitchell doesn't list a P2104 for the Aveo. This code also seems to be specific to Fords. Problems with the TAC after jump starts are caused by the initial low battery voltage and the jump start. This is fairly common on electronically controlled throttles. Since the code cleared by it self you shouldn't have to worry about it. ...


4

For the DIY mechanic without access to sites like Alldata or the experience of a professional mechanic, I'd like to add a third option to @vini_i's answer, and that is a simple google search with your make, model, year, and the fault code. I have found that often times a specific make and model will have a common failure that results in a fault code. You can ...


3

Some parts of the OBD-II code are the same for every vehicle (year/make/model independent), while others can be specific to a make and/or model. The year is usually irrelevant, though there has been some amount of change since OBD-II standards have been implemented. The website OBD-Codes.com explains the breakdown fairly well: The first character ...


3

Sounds to me like one of the spark plug wires isn't fully seated. I would check both ends of each cable and make sure they're fully seated. The engine code it produced should give you some idea where to start: P0300 - Random or multiple misfires P0301 - Misfire on cylinder 1 P0302 - Misfire on cylinder 2 P0303 - Misfire on cylinder 3 P0304 - Misfire on ...


3

Your engine should run smoothly the second you change your spark plugs, smoother than before even, that's the whole point of replacing them. Otherwise, something else is wrong or was performed improperly.


3

The first thing to do is too take the EGR out of circuit. A quick and easy way to do this is to cut an old metal oil can(its thin enough for scissors) so you have a piece of the can that will fit between the bolts of the EGR. Tighten the EGR bolts up with the can acting as a gasket. Now try watching the MAF sensor voltage as you rev the engine sharply and ...


3

This is assuming you don't have access to a scantool that can communicate with a Honda ECM and without bidirectional controls. Key On Engine Running (this may work Key On Engine off) disconnect the Air Fuel Ratio sensor connector. On the harness side connector Check for power on pin 4 (white). Check for ground on pin 3 (white/black). If you don't have ...


3

I'm leaning towards the throttle position sensor being out of adjustment/bad or a bad mass airflow sensor. Perform a volumetric efficiency test, record your IAT in °F, RPM and MAF in g/s. Use an online calculator like https://www.otctools.com/ve. You may want to do multiple pulls to get an average. TPS voltage at idle should be around .5v and at wide open ...


3

I'd advise against repairing ECU's, and splurging on a brand-spanking new one is, in my opinion, excessive. Get one from the junkyard, make sure the vehicle you are pulling it from has the exact same options, exact same engine, exact same transmission.


3

My immediate idea was that P0506 means there is a vacuum leak somewhere. I googled for P0506, and the first page I found also mentions vacuum leak as the first possible cause of failure: https://www.obd-codes.com/p0506 ...although to be fair, there are some other possible causes as well. A 13-year old car that has been driven in high temperatures can ...


3

First let's define your query to the ECU: 19 - ReadDTCInfo 02 - Report DTC by Status Mask 08 - Status Mask Ignore all this, it's only the module taking a moment to reply 77F 03 7F 19 78 77F 03 7F 19 78 77F 03 7F 19 78 77F 03 7F 19 78 77F 03 7F 19 78 77F 03 7F 19 78 This is a multi-frame message 77F 10 6B 59 02 99 00 00 ...


2

Rather than reprogram the ECU to ignore the sensor (which could then cause problems in the event there was a problem with your engine oil), why not simply replace the sensor. I'm sure it will be an inexpensive part when compared to the potential damage running with an unreported oil fault could cause. Also, as you say you've checked and replaced the sensor ...


2

I spoke with a few friends who do their own car repairs or who are professional mechanics. Their recommendation with any OBDII device is to capture any data that the device can capture and log it as long as the device or connected computer/tablet/phone can log it. It is better to have a data point and not need it than to need a data point and not have it.


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