What is DTC?
Computerized engine control systems have a certain amount of built-in self-diagnostic capability to detect problems that affect engine performance and emissions. The same is true for the antilock brake system and other onboard systems that are computer controlled.
Related Terms: OBD-II
When a fault is detected, the computer will store a diagnostic trouble code in its memory and illuminate the "Check Engine" light. On some vehicles, the computer can be put into a special diagnostic mode by grounding certain terminals on a diagnostic connector. This will cause the Check Engine or other lights to flash out the fault code. On many vehicles, though, a scan tool must be plugged into the computer system to access and read the codes.
Roadi Testimonials
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Date: 7/17/10 Source: amazon.com Unit: RDT40 Name: Sau |
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| Comment: This is the first time I have used a code reader. Instruction in the manual is clear and the reader is easy to use. You don't have to be a mechanic to use this tool. I was able to clear the error codes on my Toyota Corolla and my Mazda MPV. It was an excellent deal for $35 w/o tax & free shipping. | ||
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Date: 7/01/10 Source: amazon.com Unit: RDT55 Name: Gourd |
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| Comment: I can't say enough positive things about this device. If you own a modern Volkswagen or Audi, many of the codes and engine diagnostic data packets can only be read by a device such as this, or through a system called VAG COM. A VAG COM reader would produce far more detailed information, but is more expensive than this device. This is an excellent alternative for those like me who feel comfortable doing minor maintenance and repair on their car, but feel most comfortable taking more difficult repairs to the dealer or mechanic. As many dealerships, such as the ones near by me, CHARGE a diagnostic fee just to read codes, this can save you money in the long run. In my particular case I as able to determine that I had a bad battery, figure out which chambers were misfiring and replace the coilpacks on them, and read the upper and lower range of voltage on an oxygen sensor that appeared to be defective. Build quality is good, and using the device is very simple. It also comes with a decent tote bag. The device can be updated through use of a USB cable, but I haven't had the need to attempt this yet. | ||
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Date: 6/29/10 Source: amazon.com Unit: RDT45 Name: Fly Fisher |
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| Comment: Needed to check ABS fault in 1997 VW. Worked exactly as described. Found faulty RF wheel speed sensor and ordered new one from AutohausAZ. Well worth the investment. | ||
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Date: 6/08/10 Source: amazon.com Unit: RDT40 Name: Guy Ashdown |
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| Comment: DOES EXACTLY WHAT IT SHOULD!! Tells you codes, emission readiness,resets check engine light, this thing is great ....period!!! dont spend a wad until you try this one!!! dont be fooled by those auto parts stores who check your codes for free!!! they dont erase codes all the time!! there just like a shop...looking to make money!!!DO IT YOURSELF AND SAVE MONEY!!!DID YOU KNOW YOU CAN MAKE A LIGHT COME ON BY PLUGING IN FAULTY CODE READERS? EMISSION PLACES DO IT ALL THE TIME!! BE PREPARED!!!HELP YOUR SELF!!! IF NOT THIS ONE, GET ONE PERIOD!!! | ||
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Date: 5/29/10 Source: amazon.com Unit: Turbo Gauge 3 Name: ESTEN |
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| Comment: The unit does what they promised it would do. Using it is verry easy,so you will not need the the poor quality manual much. The gauges are not really real time, but that is to be expected, and for me no problem. I used it to reed the fault codes on my mazda tribute. The unit gave me p0305 which is misfire on cilinder 5. After swapping the coils 5 and 6, and clearing the codes, the unit gave me p0306. This way I was sure that the coil was the problem. I ordered a new one, put it on, and cleared codes (and turning of the check engine light), saved some money doing it myself. | ||
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Date: 5/22/10 Source: amazon.com Unit: RDT45 Name: P.Price |
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| Comment: I have a 2001 VW Cabrio that used to be my mother's. The Check Engine light used to cause her concern. She'd get it checked and they'd tell her, "Don't worry about it." I've had the car for a year and the Check Engine light has come on a couple of times for me. In contrast, the Check Engine light has NEVER come on on my '98 4Runner that we purchased new. Rather than run to Auto Zone or Pep Boys every time the light comes on, I purchased this hand-held. I found it rather easy to use and best of all, I can check it myself, log the results and reset the light. Well worth the cost; I'd recommend. | ||
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Date: 4/13/10 Source: amazon.com Unit: RDT40 Name: ekdm40 |
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| Comment: Just purchased this OBDII code reader to help me with my pathfinder issues. Never owned one before. I saw all the other OBD's on amazon. The most popular looked to be the actron. However, I liked that this one most probably made in china is sold from Roadi in Michigan. I figured if it broke I could at least call them and complain. So far I hooked it up to my vehicle it worked just fine, gave me all the error codes and I was able to clear the coded for now to test the new sensor I just installed. The instruction manual was clear. I read other reviews that say others had little or no manual with their readers. All in all a powerful little tool that seems to be a great buy. | ||
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Date: 1/28/10 Source: Amazon Unit: RDT55 Name: undisclosed |
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| Comment: This unit does what it claims, but I could have bought a more basic unit for a cheaper price that will do the same. Or spent the same on a unit that could do more. A must have and decent item to have if you want to do a basic check of your cars trouble codes. | ||
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Date: 1/25/10 Source: Roadico.com Unit: RDT55 Name: Duncan |
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| Comment: The RDT55-Roadi is the very best purchase I've made in a long time... It's made repairs easy and time saving. | ||
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Date: 1/20/10 Source: Amazon Unit: RDT69 Name: undisclosed |
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| Comment: Excellent Service | ||
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Date: 12/18/09 Source: Amazon Unit: RDT45 Name: undisclosed |
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| Comment: wish it came with a manual where this was on my car but when I found it, it worked great and I am relieved it is what hubby thought (glow plug) | ||
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Date: 12/14/09 Source: Amazon Unit: RDT51 Name: undisclosed |
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| Comment: Good Product and great shipping. | ||
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Date: 11/19/09 Source: Amazon Unit: RDT45 Name: undisclosed |
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| Comment: The device reset my airbag light, I didn't have to pay VW $115.00 to reset it. | ||
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Date: 11/15/09 Source: Amazon Unit: RDT51 Name: undisclosed |
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| Comment: Goods already received, as described nothing to report. | ||