Check Engine light on 2002 Toyota Tacoma Pre Runner 3.4L V6

I'm a noob when it comes to doing any car work, just getting that out of the way.
Truck just hit 91K and the Check Engine came on, the only thing I know to do for this is check the gas cap. (it's fine)
In the past I've always taken my cars to the shop and crossed my fingers hoping for the best, this time I am thinking about getting a code scan tool and seeing if I can diagnose the problem.

The thing is, there are some scan tools for ~$30 and then there are some for ~$250, there doesn't seem to be much in between.
Any recommendations on a scanner for a 2002 Toyota Tacoma pre runner? Are the cheaper ones worth it?
Should I just roll over and take it to the shop and cross my fingers?

This is literally the first problem I have ever had with it, love my truck, not happy about taking it in.
Any advice would be appreciated.

 

Folks here, at least in my limited experience here in the 1st Gen section, are very much oriented towards doing it yourself. A goodly number of the guys here have done stuff to their trucks that you (and I) probably wouldn't consider, such as replacing the engine.

So, with that in mind, I submit to you that the price of a low-end scan tool will not even rise to the cost of having a dealership plug their own scanning equipment up to your truck. At least, with a scan tool, you could pull a code and offer the code to the forum for comment.

Welcome to Tacoma World.

 

Thanks, still looking for a recommendation on an inexpensive scan tool, they seem to be a mixed bag of reviews on these things.

 

I haven't begun to learn all it can do but may want to read up on this. http://ultra-gauge.com/ultragauge/ultragauge_wired.htm

Much more than a scan tool.

You can also take it to an auto parts store and they will pull the codes and tell you what they are. Of course, once you leave you're back in the same position of not having a code reader

 

I suggest that you take her to an O'Reilly or another auto parts store and get them to scan it for free and write the codes down... do not let them clear the codes and do not buy the parts they are trying to sell you. They are using the scanner as a sales device and rarly do the parts they want to sell you actually fix the issue. I suggested that you dont get the codes cleared because if you cant fix her the tech who has a more sophisticated diagnostic tool will need all the info stored in the PCM. Not all faults trip the CEL. CEL = check engine light. Get back on the forum and give us the codes and you will get lots of people who have seen this before and eventually she will be fixed.

As to the scan tool recomendation, everyone has their favorites. While the generic term "scan tool" is used this is far from an accurate description. Some scan tools only do just that, scan the PCM for codes. Some can scan all of the other modules(ABS, Body Control etc) that are present on a modern car, some cant. Usually the more expensive the tool the more it can do. The thing that most people dont know is that there is the ODBII "standard" or generic OBDII protocol and then there is the manufacturers specific protocols, which is much, much more detailed.

If and when you decide to buy one, I have found that for the $ spent, the BlueDriver has the most tech user features. The data sampling is a bit slow but it gets the job done. I like ones that will do graphing. Some will clear the maintanance lights on some vehicles and it is my experience that I always seem to have the one make or model that reguires the purchase of a different scan tool... there is no "one ring to rule them all" scanner.

 

I have the simple one at the link below. I have no point of comparison, but, for $35, it works.

$28 Autel Professional OBD2 Scanner AL319 Code Reader, Enhanced Check and Reset Engine Fault Code, Live Data, Freeze Frame, CAN Car Diagnostic Scan Tools for All OBDII Vehicles After 1996, 2024 Upgraded

https://www.amazon.com/Autel-AutoLi...=1544893079&sr=1-4&keywords=autel+code+reader

 

OK I went to autozone used their tool, nothing came back, no codes.\Did it 3 times, plugged it in, turned to on position without starting engine and didn't push any buttons.
Even had the counter person do the same thing, nothing at all.
Didn't buy a scanner there I figured it may do the same thing as their scanner did.

When I got back in the truck the CE light was off, after ~1/4 mile it popped back on.

So I guess it's going to the shop =(

 

OK I'm goi

If I get one I think that's the one to get, and autozones tool cleared the codes I'm thinking because the light was off when I left there then popped back on 1/4 mile later.

 

Not picking on you... the tool is only as good as the guy using it. I do not know if the tool or the tool operator knows about "pending" codes. These are code that are stored in the PCM but havnt yet risen to the point of setting the CEL. If your CEL self clears then it is more than likely a evaporation type code... gas cap, evap vacuum line something non mission critical.

 

I don't feel picked on =) The counter person did it to, seemed like a minimal tool to me so who knows. The fact that the light was off when I drove away from Autozone, then came back on 1/4 mile later, suggest that their tool clears the codes too.
The truck runs fine, everything seems good, except there's that light.

 

I had my first CEL ever a couple months ago. "Reset" the gas cap and after a couple days (two 8 hour rest periods) it went away and has not come back.

 

I was cross shopping too between this one and some in the $150 range because I do work on my truck too but honestly unless you are a full blown mechanic that knows how to read all the data and knows what to do with it, there’s no point in those high end ones. Just buy a $30 from Amazon and read codes from there. At best I use it for live data sometimes but honestly you just need the code reader/clear ability

 

I have a Bluetooth dongle and the torque app on my phone. It works well and links the codes to the internet for explanation. There is a thread on here somewhere about the torque app.

 

OK so I bought 2 things, a new gas cap as the sealer ring on the old one was split, and a bluetooth dongle that works with the Torque app.
It's cheaper than the Bluedriver, so I have to wait and see if it works.

I'll report back when I get it, should be next week, but it's close to xmas so maybe longer.

 

The error coming back form the Torque app is P1135
Log snippet:
P1135: [Toyota] Air/Fuel Sensor Heater Circuit Response. (Bank 1 Sensor 1)

 

Pretty sure that means you need to replace that sensor. I had a P0135 code a few months ago (rear oxygen O2 sensor heater circuit malfunction) - I replaced that O2 sensor and it solved the issue.

I believe you got that code because the ECU is receiving a bad signal from that air/fuel sensor so it likely needs replacing.

 

That does seem to be the most common problem, groaned when I saw "ECM failure" as a possibility (bad experience with a Ford ECM), but am I correct in assuming if the truck is running fine that the ECM must also be OK?

 

yeah if you were having an ECM failure I think you'd have a host of other issues as well...not something you really ever hear about happening with a Toyota (not saying it hasn't happened but I think that's a last resort diagnosis)...I'd start by replacing the sensor, they aren't very expensive. Make sure you get a genuine Denso brand sensor though, there are a lot of aftermarket ones and Toyotas don't like anything other than Denso. Also beware of fake Densos being sold for cheap on places like Amazon and eBay. Toyota Parts Dept. or an auto parts store is your best bet, I got my sensor through Pep Boys.

 

Thank you for all the help guys, really appreciate it.

 

One other question, it doesn't hurt the truck to drive it if the problem is the air fuel sensor gone bad does it?