In my Toyota 4Runner, year 2000, 4WD, last Saturday an indicator light with the word "Check" and above it the shape of an engine turned on. Checking the owner's manual it recommended to take the car to a dealer as soon as possible.
Today I took it to the local dealer. They spent about 4 hours at a cost of $
225.00 to find out what was wrong. They came with the answer that the odometer and speed control needed replacement, at who knows what additional cost, they will quote tomorrow because their parts supplier was already closed.
I am not sure if they as BSing me, but I feel very uncomfortable about the whole affair. Shouldn't the electronic computerized diagnostic have uncovered this immediately? Has any one out there had a similar experience? Any comments, suggestions? Thank you.
People often think that when the diagnostic trouble codes stored in electronic control units point to a component like a speed sensor then the component needs replacement. What the trouble code is actually pointing to is the circuit for the component, which, of course, includes the component. The circuit includes power and ground for the component, signal wires, and all of the connections in-between the ECU and component.
You mentioned that the odometer and speed control need replacement but there is no component called a "speed control". There are vehicle speed sensors in the transmission and in the speedometer/odometer assembly, and it sounds like they are talking about the sensor in the speedo head.
4 hours just to diagnose a speed sensor circuit sounds like a lot but it does not sound like a lot to diagnose and replace the speedo head assembly because part of the dashboard has to come apart. If the 4 hours includes diagnosis, removal, and replacement and you have to add the cost of the parts, that sounds reasonable.
Your car is fitted with an engine management system called OBD II (On Board Diagnostics, Level 2). This means you can buy a tool for about $100 (USD) -- less if you shop on eBay or look around at the local auto parts stores -- that plugs into a data port that is located along the bottom edge of the dash board in the area where your left leg is placed while you are driving.
You can plug the code reader in, and in less than 30 seconds, you will know what made the Check Engine Light come on.
The short answer to your question, shouldn't the reader have figure this out much faster? is a resounding YES. Now, it could have told the mechanic what made the light come on, but they spent 4 hours trying to isolate the offending sensor. I have to agree with you, I am uncomfortable with the $225 bill to take a guess at what to do next.
What you need to do is arm yourself with information. If you are in California, you can go to AutoZone stores -- I am not sure about Kragen -- and they will allow you to use the code reader for free. Give them your driver's license and you can use the tool in the parking lot, put the tool on your credit card and you can take it home for the weekend, then get a credit posted to your card when you return the tool. (If you use the tool in the parking lot, it's free, or you can take the tool home for the normal sales price, then get a full refund when you return it, making it free to use this way as well.) I am not sure how other states handle consumers having access to this tool, but in California, you have every right to learn what is wrong with your car BEFORE you hand it over to the repair shop. If you haven't got an AutoZone, then go to pretty much any auto parts store and ask if they have a Loaner Tool Program. If they do, then they should have the OBD II Code Reader. If you weren't aware, many of the national chain stores will let you used specialized tools for free.
A popular misconception. A diagnostic trouble code and code reader will not tell you what made the malfunction indicator light come on, but it will tell you what circuit or system made the malfunction indicator light come on.
Anyone that replaces components identified by a code scanner without actually checking to see whether the component is good or bad is lazy or incompetent.
For example, in the OP's case, it could have been a loose connection to the speed sensor, a shorted or open wire between the speed sensor and the ECU, a faulty speed sensor, or a faulty ECU.
Agreed. One doesn't blindly replace the first thing that the reader tells them to, but they inspect that part and investigate the integrity of the connection.
But, when the code reader says the framis circuit caused the error, then the owner has a reasonable question when he is handed a bill for the installation of a new doohicky, and a thorough cleaning of the whatsit valve. Unless these things are inline somewhere in the framis circuit, they ought not be on the service ticket.
Any owner is smart to own a code reader for an OBD II compliant vehicle. More often than not, the reader will pinpoint the correct part. My strategy would be to list up the codes and reset them, then see if any of the listed codes repeat when the light comes on again. This is a good strategy for many of the codes, especially for the Evaproative Control System Malfunction codes - P0440 for example. This is the code that says the gas cap isn't sealed well. It really means that there is a leak in the Evap Cont Sys, but since the gas cap is frequently taken off and put back on, and the owner/operator can fit it incorrectly, then it usually means that the gas cap is not sealed. If the owner/operator resets the code, and takes care to properly fit the gas cap, then he or she will have a benchmark to have the hoses checked if the light comes back on and the code is P0440 again.
Personally, I think the service center should be required to write the OBD II Code on the service ticket so the consumer can check to see if the framis circuit, the doohicky and the whatsit valve are even related to the reported malfunction. The goal here is to disclose to the consumer what the service guys did, and why they did it. Since the service center is not required to write the code, then the owner/operator of an OBD II compliant vehicle should have a code reader in his garage, just like he would have a hammer and a pair of pliers. The consumer might not be able to use the knowledge he would gain from having the tool for anything other than asking if the doohicky and the whatsit valve are part of the framis circuit, then asking why the framis wasn't serviced when the code clearly said that was the problem.
Most of the codes are pretty specific, and there can't be very many other things beyond the framis circuit that can throw the framis circuit code. If there is something that can affect the framis circuit, then it will have a code of its own. Or, it will be a sub code of the framis circuit codes. For example, the framis circuit will have a failure and the code is a general framis code such as P0440, then there will be other codes that tell the precise section of the framis circuit, or that the particular part is open or shorted or otherwise out of range, in this case the code might be P0441 or P0442, etc. (NOTE - I know the P0440 codes are the Evaporative Emission Control System, not a ficticious Framis Circuit.)
In any case, the OP would be a much smarter consumer of vehicle maintenance services if he or she had an OBD II Code Reader that he owned or could use in the parking lot of the local parts store.
I agree if the owner has more than a basic knowledge of how the auto works. If not, then all the owner gets is information that he/she would not know how to use. For example, if you ask 100 people what the most likely cause of an evap control diagnostic trouble code, at least 99 won't have a clue what you're talking about.
Good idea, I agree. BTW, if you want the service departments to record the DTC on the service ticket (known as an RO-repair order at Toyota dealers), just ask and make sure the service advisor records your request on the RO. The techs are supposed to record the DTC on the back of the hard copy (service dept copy) of the RO so it is a simple matter to record it on the customer copy.
I own an OBD II code scanner so I would just fix the problem myself.
Again, I'm not so sure the information would actually be useful to most consumers. For example, "too lean bank 1" does not tell the consumer what is causing the engine to run lean. I saw a post that implied that the customer thought that the engine was leaning over.
I'll plead incompetence. Hell, if the Check light even comes on, I just got out and buy a new O2 sensor!!!! (were talking 2 1985 Toyotas here...the only other thing was the knock sensor became unplugged somehow...)
Hachi, no offense intended! I should have been a little clearer. The "anyone" in my mind was someone who is taking money to diagnose and repair the problem, a so-called pro. I wouldn't expect most DIY-ers to be able to check whether a component or the circuit is functioning or not without a manual, and since the component itself is often the culprit, replacing parts without actually checking them is a reasonable move.
BTW, a knock sensor is just a piezo-electric crystal like the sparkers on grills and lighters. When you compress the crystal, static electricity is produced and if there is a path to ground nearby, a spark is produced. When the engine pings, it compresses the crystal in the knock sensor, which produces a spark. The ECU senses the presence of voltage when the spark occurs and retards the timing. To check if a knock sensor is good, put a volt meter on the wire coming out of the sensor, hit the block near the sensor with a hammer, and see if the meter detects the flash of voltage.
I recommend doing this with 2 people - someone to whack the block and someone to watch the meter (unless you have one of those fancy data recording meters). If you try to whack the block while watching the meter yourself, there is a slight risk of striking the knock sensor itself, which busts the sensor housing and then you end up needing a new sensor anyway. Destructive component testing sucks!
That's probably a reasonable strategy for an '85. but the '96 and later models have a consumer-friendly computer. Well, as friendly as a computer can be, I suppose.
One could check trouble codes on an '85 with a paper clip - not exactly special equipment, although I do keep one in my tool box for that purpose.
Newer vehicles require access to an OBD II code scanner, which means purchasing one, a trip to a parts store, or a trip to a service facility. It's nice to have the codes more readily available and to be able to pull the codes without having to crawl under the dash.
"Shouldn't the electronic computerized diagnostic have uncovered this immediately? "
It's extremely difficult (read impossible) to develop a diagnostic system that isolates exactly which part failed 100% of the time. This requires the engineers to figure out, ahead of time, all the possible million ways your car can break, then add monitors to detect the million failures. Of course now you have a million monitors that can break causing false failures, so now you have to have monitor your monitors!
Most of the time the diagnostic will tell you generally what system failed, could be the sensor failed, could be the computer that uses the sensor failed, could be the wire that connects the sensor to the computer broke, could be the monitor failed or could be some other unrelated sensor failed which falsely caused another sensor to indicate a failure.
So they might of been tracking this down or eating doughnuts for 4 hours, who knows.
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