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| Thread ID: 95920 | 2008-12-21 18:11:00 | Vehicle computer | Paul Ramon (11806) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 731502 | 2008-12-21 18:11:00 | Most vehicles today seem to be controlled by a computer. Is there a special cable I can get to connect to a laptop (along with what? software) to self diagnose problems etc? Or is using a laptop out of the question? | Paul Ramon (11806) | ||
| 731503 | 2008-12-21 18:39:00 | I think you'll find it's a bit more complicated than that - I imagine the diagnostic software, even if it's available to the public, is different per manufacurer and that the cable each manufacturer uses to conect a vehicle to its own diagnostic unit has very specific plugs. There are bigger petrol-heads on the forum than I, so I am sure you'll get a definitive answer... |
johcar (6283) | ||
| 731504 | 2008-12-21 18:48:00 | Are you serious Paul. If you have a problem with your car take it to the experts, modern car electronics are not DIY. |
Safari (3993) | ||
| 731505 | 2008-12-21 19:17:00 | No way paul - only realistic way you can do that is if you have an aftermarket ECU, and then you need to know what you're doing. | wratterus (105) | ||
| 731506 | 2008-12-21 19:55:00 | No way paul - only realistic way you can do that is if you have an aftermarket ECU, and then you need to know what you're doing. Do you think garages have different scan tools for each model of car? Of course not. First thing you need to find out is what protocol your car uses. Still need to know what you're doing :D |
PaulD (232) | ||
| 731507 | 2008-12-21 20:08:00 | Do you think garages have different scan tools for each model of car? Of course not. First thing you need to find out is what protocol your car uses. Still need to know what you're doing :D You'd need to get hold of the correct cable for a start, that could potentially be difficult, although it's similar for most jap models. |
wratterus (105) | ||
| 731508 | 2008-12-21 20:17:00 | Professionally, I used the Snap-On MT2500 with appropriate cartridges for Y/M/M and of course, the "Troubleshooter" cart to work out the repairs as they came up . CEL or SES lights on the dashboard tell the owner that something is amiss, but many prefer to ignore it since they have checked the oil, coolant and belts and hoses and stuff and figure that somehow the "computer" is speaking nonsense and can therefor be ignored . Wrong on all levels . What the ECM sees is something that is out of range in the controls/sensors/stepper motors/drivers somewhere, and it has nothing to do with normal service items . It depends on the level of sophistication that your vehicle employs . Is it OBD-1? Is it OBD-2? Does it use an ALDL (link)? There are ways to access the codes and troubleshoot the problem and the latter OBD-2 system affords "on-the-fly" diagnostics and running data streams, but they happen so fast that they don't provide much info to the novice . Most (if not all) scanners use a stream of information as they say "real-time" which it isn't; after all the CPU in the ECM runs at 33kHz, and I cannot see a refresh rate that is as fast as that and as being humanly legible . Therefor they map "trends" and use freeze-frame accounting for the required parameter in question . Newer vehicle on-board diagnostics take a "movie" of the malfunction and that can be spooled to see the time, RPM (TAC), throttle position (TPS), road speed (VSS), baro-values (B_MAP or BARO), air flow into the plenum (MAF), manifold vacuum (MAP), transmission position (TCC/ON-OFF), Gear Position (GP1), Selector Position (SP1), Heating or air conditioning load (ACO) request including the high-side pressures (ACH) and even the battery temperature (BTV) when the problem happened . So, you can see that there's a lot of sophistication . You CAN get the correct USB-to-ADL or USB-to-OBD2 port access link dongle, as they DO exist on some sites, but I prefer to buy mine from tool dealers that specialize in that hardware and firmware . There are some proprietary codes that are useful to the manufacturer ONLY, but the generic codes are very succinct and useful to the average owner . /operator . Other codes and resources and accessible on the aforementioned bi-directional scanner as it is so on quite a few others . Some can blink a code with just a bent paperclip, inserted in the CORRECT place: others require expensive diagnostic devices . Tell me the Y/M/M and engine size of your vehicle and I'll see what info I can get for you . . . OK? |
SurferJoe46 (51) | ||
| 731509 | 2008-12-21 20:18:00 | Do you think garages have different scan tools for each model of car? Of course not. First thing you need to find out is what protocol your car uses. Still need to know what you're doing :D Just had a horrible daydream then about Microsoft expanding into the automotive industry; can you imagine ECU's running Vista? Do you wish to mix fuel and air? Are you really sure? ECU has performed and illegal operation - please pull over, and download Silverlight to experience a new driving experience :p |
nofam (9009) | ||
| 731510 | 2008-12-21 20:29:00 | :eek: :waughh: :help: | wratterus (105) | ||
| 731511 | 2008-12-21 20:35:00 | you can get basic real time read out from the ECU. kinda handy as then you don't need multiple gauges on the dash. one i know of is scanguage. there is a few on ebay selling code readers for certain vehicles. some vehicles use standard systems but others do not. the catch to is the ECU will log fault codes but not necessarily flash any warning lamp to say there is a fault. part of normal service is for the manufacture to plug in their code reader or diagnostics to see if any error faults have come up. i might just go get a code reader for the work vehicles as we do all our own servicing. |
tweak'e (69) | ||
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