I know most of this doesn't exactly pertain to the 80-86 F series trucks, but I'm sure most of the guys and gals here can relate.

I've got a 1995 Mazda B2300 pickup, which is essentially nothing more than a Ford Ranger with Mazda badges on it. This model just happens to be one of the first to incorporate the "new" OBD-II (On Board Diagnostic, 2nd generation) standard that became mandatory for the 1996 model year and beyond.
OBD-II added several things to the older OBD-I system that several trucks in the 80-86 model years were equipped with. One of these "features" was a standardized communications port, regardless of vehicle manufacturer. No more need for a different scanner tool for different makes, as 1 scanner would now service all makes. Big improvement over the old system.
There was also a great many additional items that were to be monitored by the engine management system, which would (in theory) help keep everything working as it is supposed to. However, there's a flaw in the overall design of these systems. That flaw is the single function warning light to alert the owner/operator of some type of fault in the system, the "Check engine" light (CEL).
This "CEL" needs to die, now. Here's why: The system detects a fault, and turns on the light. This fault can be something minor, which can be overlooked for a while, or it can be something major which, if left alone for any length of time could result in the vehicle becoming inoperable. The problem is, this STUPID light doesn't perform any different function to distinguish between a minor or major issue, it simply comes on and refuses to go out until the system has been hooked up to a scanner, and the trouble codes retrieved. This can, depending on where a person happens to go, cost anywhere from nothing to well over $100, just to find out why the light is on. This does not include any cost of resolving the the problem that caused the light to come. Can you imagine having to pay someone $100 just to tell you you forgot to tighten the gas cap? This has happened, probably many more times than you could think.
Why can't this light perform different functions, for different levels of faults? For the sake of arguement, lets say have it flash a few times then go out for minor faults that should be looked into when it is convenient for the owner. More serious issues, the light could flash longer. For something serious enough to potentially cause the vehicle to become inoperable, the light could come on, and stay on.
I know this is possible, and it was possible from the beginning. My 1995 B2300 also has an airbag (Supplement Restraint) that has it's own separate light. When this system detects a fault, it flashes a series of times, and counting these flashes will give a 2 digit trouble code. After flashing the trouble code a few times, the light then turns on, and remains lighted the entire time the vehicle is running. If this light happens to burn out, and it will eventually since it lights up everytime the vehicle is started while it performs a "self test", there is even a backup system. The airbag module will emit a very loud beeping, to alert the driver that there's a problem with the system, and the warning light cannot function to alert them about the issue.

Now, we get to something that will likely sound crazy. Why in the world isn't there a display screen on the dash that can inform the driver about the nature of the fault that has illuminated the aforementioned check engine light? Just about every other type of display has been added to the dash, including radios that can display the name of the song, and singer/band performing the song, from a remotely broadcast station.
I'd think having a display that can alert a driver to the severity of fault detected in the engine management system is FAR more important than the name of the song playing on the derned radio.........

If you've read this far, you've probably figured out that the check engine light came on (again) in my 95 B2300, and that it was (again) caused by an extremely minor fault.
This time it was for low EGR flow detected. DUH! I got tired of the light coming on everytime I turned on the A/C, to complain about excess EGR flow, and disabled the entire EGR system. It "only" took the STUPID light 3 weeks to decide there was not as much EGR flow as expected (none, in fact) and turn on......
With the EGR disabled, the truck runs better, gets better MPG, and can even keep the hot-headed loose nut behind the wheel cool.
I dern sure don't an idiot light on the dash to tell me there's no EGR flow. I'm the one who unhooked it. I'm also the person who erased the low EGR flow code from the ECU memory, for now......



I sure miss the simplicity of older vehicles, where a person with decent mechanical abilities could diagnose and fix faults without needing a bunch of pricey diagnostic gizmos.......


Rant mode off, for now.

 

This is what I think NumberDummy would say as to why it's like it is....

The manufacturers are in business to make money, and they get more of it when people bring in their cars with a CEL on no matter the cause.

My personal opinion is that things like that would be too confusing for some/a lot of people, and some people would misinterpret the different lights/codes/whatever and end up destroying their engines and then suing the manufacturers for making a confusing warning system (it's always somebody else's fault).

 

That's why I advise everyone to take their vehicles to an Oreilly's, an Autozone, or an Advance if they can. I know Advance and Oreilly's both give free OBDII checks, so no money out of your wallet.

I also agree with the second statement about warning codes/lights. This is why I support RW's idea of a display on the new vehicles that tells you what the problem is, and or gives you the code. It's easier because there's no code reader needed, but like you've already pointed out, it's all about money. The dealers want you to pay them to tell you what the problem is, then they'll probably tell you it's a "dealer only" part so they can have you have them fix it too. We all know how much dealers jack-up repair prices too.

RW, regarding the EGR valve, I know on a 92 to 96 Ford 300-6, if the EGR is letting in too much exhaust gas, you can always undo the EGR tube running to the EGR and drop in a fender washer and tighten it back up. This restricts the EGR's flow to acceptable levels so that the EGR doesn't cause a problem, yet still leaves the system functional. Different size washers with different diameter holes would let you "tune" the EGR system and eliminate excess flow. If you can still hook it back up and you can do the washer method, I'd try the washer method and see what you get. I'll bet it solves your problem.

The washer method came about because people got excess EGR flow and replacing the valve wouldn't cure the problem. So, to fix the problem, people would either build block-off plates, or, after the idea went around, do the washer method.

The washer method got popular because it restricts EGR flow to an acceptable level while keeping the system functional... and on vehicles that had an inspection due, you couldn't see it just by looking at it. You would have to physically start undoing engine components.

Pretty slick if I do say so myself.

But yes, I'm like you. I like older vehicles because I can fix them myself. I was born in this "fuel injection era" but have parents that remember the good old days of the points ignitions, and the simplicity that comes with them. That, and every vehicle that I've seen them own that has had fuel injection usually has some ridiculous fix (like yours) to get everything functional again, whereas on a carburetor with electronic or points ignition, you could service it and be right back to driving it daily (or in most cases, driving it while the problem is present, without any danger).

 

I understand completely on the stupid lights.

My Ranger has a faulty Torque Converter Control solenoid that causes my transmission to shudder in overdrive. Because the solenoid is electronically controlled, it is monitored by the engine computer. If I let the truck go into overdrive and the transmission starts to shudder, the trouble code for the solenoid gets sent to the computer, and the Transmission Control Unit puts the transmission into limp home mode. This means that full fluid pressure is sent through the transmission to make sure it shifts into 1st and 2nd gear. It makes for VERY rough 1-2 shifts, and isn't good for the transmission at all. There's nothing wrong with how my truck shifts, and it always goes into gear just fine. The only problem is in Overdrive, but the computer still pretty much shuts down the transmission because it thinks the transmission is about to start blowing parts out of the pan.

 

I just carry a code reader cable that links to my iPhone via wifi. Read the code, reset it if needed, and don't worry about it. But, I sure like being able to fix things, or improve them, on my truck.

 

I have several code readers. Actually, the computer makes it easier by telling you what is wrong.....

 

I know they are in the business of making money. However, the manufacturers do not make any profit from a person taking a vehicle into a dealership, other than from the replacement parts (unless under the ever lengthening warrentty). So, they don't stand to lose much, if any, money by enabling an "end-user" (vehicle owner) instant access to the "on board" diagnostic info.

I know that there are a lot of people that don't want access to that info, as they wouldn't have a clue what any of it means. However, with the different functions for the idiot light, they would at least know whether to get the vehicle into a service center ASAP or risk total shutdown, or to schedule it at their earliest convenience.



Here's what irritates me the most. I've had this truck for a bit over 2 years. In this time, the check engine light has come on several times. Everytime, it has been for something that is not "critical". It's been on for excess EGR flow almost every time I have used the A/C and had to stop at a traffic light for more than 30 seconds. In other words, very often. Hence, the reason I disabled the EGR system. More later.
It has come on a couple times for coolant temp sensor issues. The first time, I had accidentally broken the sensor while trying to inspect the timing belt. The second time, I had forgot to plug the wires back up to it, after having taken the timing belt off. More about this in a minute...
The only other item to ever cause the light to come on, was an evap system leak. I knew it had an evap system leak, as the filler neck (plastic!) is cracked. It became rather obvious the first time I filled up the fuel tank, as I overfilled it, and the fuel inside the filler neck became fuel dripping on the ground. I didn't need the light to tell me it had such a leak, especially 1.5 YEARS after I first discovered it......

EGR issues: The EGR is vacuum operated, thru an electronic solenoid controlled entirely by, you guessed it, the same dern computer that would rather turn on a light, than turn off the vacuum to the EGR valve. It takes just a few seconds for the ECU to sense the excess EGR problem and turn on the light, but took it 3 weeks to figure out there wasn't any EGR flow, and turn on the same dern light.......

Coolant temp sensor/timing belt issues: Engine ran rather poorly when I bought it (cheap, as in $700) and drove it home. I suspected timing belt improperly installed, before I dropped the cash. This is why I inadvertently broke the coolant sensor trying to inspect the belt. It sits right in front of the cover over the belt, and I made the 2 meet. $12 lesson learned, unplug the sensor before moving the cover, which led to the 2nd instance. Failed to plug it back in, and started the engine. Took all of 2 starts (test fire, and test drive) for the light to come. I knew instantly what I done, and shut it down to plug it in. 2 weeks later, I finally went to get the light shut off, which is something it should have done after the issue was corrected.

This same computer runs the entire fuel injection and ignition systems. There is no ignition module (even though several parts books say there is) as the ECU performs the functions the ICM did on 94 and older models.
The ECU uses signals from both the crank position sensor and cam position sensor to know when to fire each fuel injector and spark plug. Sounds pretty straight forward to me. However, the timing belt installed with the cam 20-30 degrees advanced, and this dern "computer" couldn't figure out that the signal from the cam sensor and crank sensor were not correctly timed with each other, and therefore never activated the light. The plot thickens even more when you consider that the cam sensor isn't on the actual camshaft, but rather down on the oil pump (where the aux shaft used to be) which is also driven by the timing belt. This was timed over 120 degrees off.
Engine ran, but quite poorly. The ECU never saw an issue with the crank/cam not being sending the correct signals, at the correct time, and therefore was totally useless at diagnosing what I would call a rather serious engine problem. This step required using the oldest computer known to man, the noggin.

In summary, the ECU has only set the check engine light for piddly little issues, while missing a rather blatant serious problem. Therefore, check engine light is totally useless, period.

 

I agree with the idea that the manufacturers should give us easy access to the data. My new Murano has a nice LCD that is used for nag, backup camera, etc and would make a perfect place to display the OBD data.

 

I'm not against the idea of buying my own code reader. In fact, I actually intend to buy one. But, I don't want one of the lower cost readers that can only pull codes from the ECU. These can be found for $50 or less.
I want one of the higher end readers that can display real-time data, and access the airbag, ABS, and any other type of system that can be read thru the OBD-II com port. These cost closer to $200.

Even the higher end "professional" systems cannot always tell you what is wrong. When the timing belt was installed incorrectly on my truck (PO did it, not me) there wasn't any trouble codes to diagnose. Should have been, since the cam and crank sensors were 120 degrees out of time........ Granted, that's just a bit further out of time than an engine could possibly run with, but since the cam wasn't but 30 degrees off, it did. All without setting off any trouble codes.......

 

Edited, for simplicity.

The i-phone has plenty of capabilities, but I never knew it could be used as a code reader, with or without added hardware.
Brings me to another (valid) point. The on board displays can even be synced to use as a link to your phone (i-phone or not). If it can place a call, why can't it tell what that silly light is trying to indicate?

 

Are you guys sure the newer cars don't already have this (or similar) capability? Displaying OBD stuff on a dash display? I wouldn't expect it to be described in the Owner's Manual but it'd be in a factory shop manual I'd bet.

I have my brother's 1993 Taurus SHO to figure out various electrical problems, he bought all sorts of wonderful Ford documentation for it. The HVAC system has its own computerized controller and its own diagnostics one accesses by pushing certain buttons in a certain sequence.

Point being, it wouldn't at all surprise me if modern cars don't have something similar to see what the OBD computer thinks is happening.

 

Some vehicle do have a way to access this info, but it typically requires doing something that resembles entering a "cheat code" into a playstation. In other words, it's a totally "hidden" feature, that requires doing something totally off the wall to "unlock".
Example, some Neon's could be turned into a self-test mode by starting/shutting off the engine repeatedly, in a very short time. Something like 10 times, in under a minute. Who would "normally" try such a silly thing?

 

Well I agree with what you said. I would add thou that my Aunt had a 2004 Ford Five Hundred, and to some extent it could tell you warning messages through a display about some of the problems. It might not have been been very detailed but it would give some indication to some of the problems and whether a visit to the service center was needed and how important it was to be checked asap. Now with that said I have no idea about the newer cars. My same Aunt has the New Explorer, and I can say the dash is loaded with all the bells and whistles. The specifics of what it had? I have no idea. But like you said, they were probably capable from the beginning.

Here is a list of some of the messages on the 04 five hundred that would warn the driver.

LIFTGATE AJAR
TRUNK AJAR
CHECK ENGINE
CHECK TRACTION CONTROL
FUEL GAUGE Op 1/2 to E Only
LOW COOLANT LEVEL
OIL LIFE 0%, CHANGE OIL
OIL LIFE XX%, CHANGE SOON
LOW BRAKE FLUID LEVEL
LOW WASHER FLUID
TURN SIGNAL ON
CHECK ENGINE TEMP
CHECK CHARGING SYSTEM
ENGINE FAILSAFE MODE
TRANSMISSION OVERHEATED
AWD MALFUNCTION
CHECK BRAKE SYSTEM
CHECK TRANSMISSION
LOW FUEL LEVEL
OIL PRESSURE LOW
CHECK FUEL CAP

See link below for more info, my Aunts warning message was check traction control, because the car was driving funny.



The Egr systems works the same on my Dodge and I find it odd that the light didnt come on when you disabled the egr, other than the low flow because a code should have been set. If i can remember correctly, the computer detects the signal from the oxygen sensor voltage didnt change when the egr preset conditions were met when the egr then were to be activated.

But yeah, that should be standard on the new cars. I rather have a more precise warning system rather than those displays telling me what songs are and etc!

 

My 1983 Mazda RX7 has full guages, like every other 1983 RX7. It also has light/warning alarm for low oil level and low coolant. These items can be low, without causing the guage to read abnormally.
It also has lights to indicate a malfunctioning headlight or brake light, even a way to let you know if a turn signal bulb isn't working (won't flash).
There's even a warning beep that happens if the tach exceeds 7K.
All of these warning lights function without the aid of any "computer", as does everything else on the car.
The only warning light that is missing, is a "low fuel" light. That came along in 84......

Notice, I didn't say anything about a backup for the volt meter? Turns out, Mazda accidentally invented a warning system to alert you when the alternator wasn't charging. Every one of those other warning lights will light up. The module that lights these up when the key is on, uses a signal from the alt to turn them off. A side effect, if the alt quits, it turns them all back on......

Point being, even most OBD-II systems don't monitor some of these same items, in spite of the serious engine damage that can occur from having low coolant or oil.


I jokingly comment about raising the hood and checking that engine is still there everytime the light comes on, and haven't yet seen it MIA.......

 

On my 1992 Oldsmobile 98 Touring sedan, the DIC (digital information center) would certainly let me know what was going on. My son's newer 08 Super Duty also has a pretty good driver information system.

For example, if the oil pressure or temp sender was out of expected range, it would report such. Of course such a system is a extra cost option, and just like buying a service manual for your paticular vehicle... some people are just to cheap to either select the optional (if offered) DIC or they will totally screw something simple up because they did not buy the proper service manual.

As to the "durn" computer not picking up that a engine has a horribly out of time timing belt, well that is because it is NOT programed to monitor that, nor is there any need to as there was NEVER any need for a ignorant or just plain stupid person to work on his/her own truck if they did not know what they were doing in the first place... Ahemmm...... perhaps that ignorant or just plain stupid person should have bought the service manual FIRST!

Computers only monitor what they are programed for.... if they were also programmed to stop peoples ignorance or stupidity, a whole lot less of us people would be driving in the first place as the computer would sense and monitor a "idiot" behind the wheel and refuse to let the car start!!

BTW - OMC (of Evinrude and Johnson fame) tried the single, but multi function warning system, in horn form, and it was not totally accepted as some people were just not able to remember what horn tone, long or short, repeating or not, meant what! (more stupid operators I guess, it was only five different and distictive warning sounds, I mean really, if someone cannot remember just five things, how can they even be trusted to be in control of anything?)

Ok ok I will shut up!

David