All too frequently, new members ask questions about codes they've received when performing a DTC scan after a check engine light appears. Many times we reply that those codes are probably not accurate due to the code reader not being Prius/Hybrid friendly. many times we recommend purchasing Tech Stream. Especially if you have multiple Prii or are a significant DIY kind of person. Here's a quick example of why. I recently purchased a 2005 with the intention of reselling it. I've been going through it a little each weekend. Today, I installed a new Inverter Cooling Water Pump and new coolant in the inverter loop. I changed the oil and filter, installing a Toyota filter and Mobil 1 5W-30. Then I drained and replaced the coolant in the engine loop. One of the common DTCs received when doing the engine coolant is P1118. Here's P1118 when scanned by a common basic OBD2 scanner made by Actron that many DIYers may own: Here's the same code when using Toyota Tech Stream: Can you imagine the confusion this can cause for a new Prius owner who doesn't know any better? There's a big difference between P1118 … Fuel Air Metering and P1118 Coolant Temperature Sensor Circuit High for CHS System If you're a new owner (or old owner) and are interested in DIY for this car, please, please, please invest a few dollars in a Prius friendly scanner or better yet...get Tech Stream. You'll never regret it......
Why would you need a Prius friendly scanner when all you need is a table of Prius code descriptions? Surely someone would have already dumped them to excel or text file by now.
Can you help me with that? I've been looking for something like that for more than a year. @TMR-JWAP says they're in the Bentley manual, but I'd rather just have them for free and store them on my phone for quick reference. I have all the error codes for Gen1 Honda Insight, but never been able to find them for Prius.
Thanks for pointing this out... It'd be interesting to see what Dr. Prius says in same situation... I bet it'd do well... Eventually I'll get around to getting tech stream up and running but have always been unable to get it to work despite repeated attempts. And I'm more focused on building spread sheets with module testing then going insane chasing down error codes. Of course getting good at error codes is unavoidable...
I will keep an eye out for them. I'm kind of new to this having just purchase a 2018 Prius Four last May. I never bothered to educate myself before that.
Helps if you know that P0xxx codes are harmonized across all makes and models, higher numbers are manufacturer-specific so they won’t mean the same thing from one car to the next.
That’s true of several ranges of diagnostic trouble codes (DTCs); see my previous posting or SAE J2012. In my opinion, the chief limitation of most third-party scan tools is not an incomplete or inaccurate list of one-line (“fortune cookie,” to use @ChapmanF's apt term) descriptions, since you can look those up in the Diagnostic Trouble Code Chart pages of the Repair Manual (more info). Rather, it’s that they often can’t communicate with several of the car’s ECUs at all, so they can’t find all of the stored DTCs, and they don’t have the data list, active test, or utility features of a Toyota Techstream diagnostic system. I could easily produce lists of DTCs and descriptions, but I’m not sure about the scope of Toyota’s or SAE’s copyright. Since most people can get access to the Repair Manual at no cost or for a nominal fee, I’m also not interested in steering people away from its procedures.
The best answer I can provide to that question is the hundreds of posts on this site asking about codes that show up on a reader, but don't even exist for a Prius. Obviously, that is a code which is being misread and having that code does no good, even if you have a "list".
Buy a bluetooth OBD2 module and get a Torque app for your smartphone. Download the Prius PIDs and customize what you want to display. Use the internet for deciphering the scan codes. $15 out the door.
How can the codes be misread when they are merely the numbers provided by the vehicle's logic/firmware?
Thanx. That make more sense. So we could probably dig up the definitions ourselves from TIS but cannot published them here due to copyright. PriusCamper, are you getting this?
If one auto manufacturer would make their shop manuals freely available, with disclaimers, I wonder what would be the outcome. Is it that much of a goldmine? Maybe a case of you get more bees with honey?
We can only speculate, but I would think that it involves something more prosaic - like simply making the information difficult to collect by limiting where and how it is documented and then backing that up with copyright and company policy. So far, the only source mentioned here is a vague reference to the "repair manual". If the definitions can be found in troubleshooting narratives and tables scattered throughout the entire manual, then you could probably collect the information for yourself (after paying a subscription fee). However, copyright restrictions would still prohibit publication... ...even publication here in PC. Otherwise, the only other place the information might be found would be embedded in Techstream source code and source code comments (i.e. text that is included in high level programming language comment fields used to describe/document source code algorithms), which would be proprietary.
Now that I’ve rented that manual (and a couple of others like it) for DIY purposes, I’m a believer. It’s a much richer resource than any of the third-party manuals, and the net cost via subscription is very low compared to the old paper manuals. Plus it is still being actively updated. I do like the readability and durability of a paper book, but the cost of suitable tablets and laptops has plummeted to the point where I don’t mind maintaining a “dirty” one for garage duty. I do still print off a few pages here and there so I can rapidly flip from one bit to another.
I have wondered that myself, but we've certainly seen the examples. It does suggest that some of the third-party code readers might be of even lower quality than you'd hope. Ok, if you only joined last May, maybe we can give you this one, but if you're talking about post #7, the person making the "vague reference" is the same person who compiled the very comprehensive wiki page about all of the Toyota service information, where to find it, what's in it, and how to use it, so maybe that counts as a little more than a "vague reference". The same link was in post #7, right after the "vague reference".
No. The "vague reference" that i was referring to was not in reference to post #7, which was accidental. I was actually talking about reference to TechStream and the use of "repair manual" in other threads as a "catch-all" answer. I just got lazy when I said it. If you read my post #10, you will see that I agreed with post #7... ...and even THANKED him for it!
apologies ... the reference to "repair manual" in #7 was the only one I could find in the thread. (Still is now, 'cept for these later ones.)
When manufacturers still produce a paper book, it forces them to achieve a certain level of continuity and presentation. Sadly, they seem to be moving away from that, and it shows.
That's because paper has become prohibitively expensive. You would be amazed at how cumbersome it is to produce accurate and effective technical documentation these days in hardcopy form.
I respect your concern for proprietary process rather than a collaborative effort. But Priuschat is a collaborative effort and no one on here has ever once complained about people using illegal Toyota Techstream software cracks on air gapped computers. What's so wrong or different than having a file of all error codes on our phone? If you can "easily produce lists of DTCs and descriptions" please do so! We aren't profiteers here, we're people who like to help people. Besides I already have all the Honda Insight Hybrid DTC and description in my phone, I'm simply wanting to offer the same benefit to friends with Prius. Helping people interpret error codes can have a huge impact on a person's financial stability these days. The more information we share, the more efficient/affordable owning a Prius can be. And anyone who's done a google search of PriusChat regarding error codes that come up will tell you what an inefficient mess that effort really is...