Arguing With A Dang Computer

I’m a reasonably good automobile mechanic and a very good computer programmer. Put the two together, however, and I got stymied by our 2003 Dodge van. Here’s the backstory.

I started learning to be a mechanic on the remote cattle ranch where I grew up. If you live at the far end of nowhere, you can’t call a mechanic or a plumber or an electrician. So you have to learn to be all of those. As a result, by the time I got out of high school, I could fix a lot of stuff. I also had a totally unjustified, unsupported, and unrealistic opinion that I could fix anything … ha.

I only got good at mechanics, however, when three friends and I opened up the People’s Garage of Santa Cruz in 1968. I was twenty-one, the other guys about the same age. The master mechanic among us four was Jeffrey. He was one of those guys who seem to have been born with a wrench in his hand. Can’t tell you how much I learned from him about auto mechanics in general and infernal combustion engines in particular. He really could fix anything.

The most important thing I learned from Jeffrey was that when you get into disputing the toss with a nominally inanimate machine, you have to be convinced that you will win. For example, Jeffrey taught me that if a gasoline engine has spark, compression, air, and fuel, it has to start. No question, no debate, it would start for Jeffrey. He knew no matter what an engine threw at him, he would always be able to get that engine running … and he always did.

So I took up that point of view, and it has served me well in a lifetime in which I can’t count the amount of internal combustion engine surgeries I’ve participated in.

And computers? Well, I first programmed a computer in 1963 … it used punch cards, and it took up a whole room. I was entranced by the process, and I have been writing programs ever since. When Tandy brought out the first “personal computer”, the TRS-80. I bought one. I wrote navigation programs for it and used it to navigate from Fiji to Tonga … however, that’s another story, and a rollicking good one to be sure, it’s the sequel to my sea tale about Modern Piracy … but it’s not this story.

And to return to this story, when IBM came out with the first IBM PC, I bought one. I drove it non-stop for a couple of years. Then Apple came out with the Mac. I bought one. I figured I’d use the Mac for graphics and the IBM for all the real work. But once I bought the Mac, I never used the IBM, and when the dust got a half-inch thick on the PC, I traded that poor computer for a piano and never looked back. Since then, among other jobs, I worked for a while running the service department for the only Apple Computer Dealer in Fiji … hey, someone’s got to do it, and the waves weren’t going to surf themselves …

So as a mechanic and a computer programmer, when I found out that our Dodge van didn’t pass the smog pretest, I figured hey, no problemo. I thought that because the issue, according to the paperwork, was that the van’s computer monitor for the catalyst wasn’t kicking in. I knew automobile engines, I knew computers, I could fix them both … and I knew absolutely nothing about automobile computers.

But hey, how hard could it be to get an automobile computer monitor to kick in?

… little did I know …

Now, all US cars since 1996, and all European cars since 2001, have an onboard computer called the “OBD” system. The acronym refers to the On Board Diagnostics computer. These days it’s mostly the second version, OBDII. The OBDII system is what watches the automotive monitors and turns on the infinitely irritating “Check Engine” light …

Now, my only good fortune in all of this was that I got a “Check Engine” light a few months ago. Sounds like bad fortune, but it wasn’t, because after I said the requisite number of bad words, I figured I should check the engine out myself. So I went and bought an OBDII reader. The one I bought is called the “BlueDriver”, ninety-nine bucks plus tax from Amazon, and it is slick. It’s just a small Bluetooth-equipped unit that plugs directly into the OBD port underneath the dashboard near the steering column.

It hooks up wirelessly with an app for my iPhone. And it is amazing what the BlueDriver can tell me about any car I plug it into. Incoming air temperature, RPM, speed, atmospheric pressure, there are monitors throughout the car that the computer uses to adjust the fuel mixture and watch for malfunctions. Man, I could have used this when I was part-owner of the People’s Garage …

In any case, I found out that the Check Engine light was telling me that there was a slight leak at the O-ring gasket at the gas cap … who knew that the car watched my gas cap O-ring?

I sure didn’t know … but I fixed it on the spot by using some spit to clean off the O-ring and I got it working again. Like I said … cattle ranch trained, use what’s at hand.

In the case of our Dodge van, my BlueDriver was able to check out the status of all of the onboard monitors. And it agreed with the guys at the smog shop. It said that the catalyst monitor wasn’t integrating into the OBD system. This kinda made sense because we’d replaced the catalyst a few months before. Upon asking the smog guy, he said that if they had changed the catalyst we just needed to drive the car for a hundred miles or so, and the monitor would kick it.

Since we’d put about three hundred miles on the vehicle since replacing the catalyst, driving another hundred miles didn’t seem like it would work. So we went back to the muffler shop where they’d changed the catalytic converter. The owner said, just drive for an hour at 55 on the freeway and the monitor will long in … hmmm. We’d already done more freeway miles than that. At this point, my mechanic’s urban legend detector was starting to go off. We called another shop. They also said put another hundred miles on it, but turn on the air conditioner and the rear defroster. Whaa?

The muffler guy recommended another mechanic. We went to him. He said the thing to do was to disconnect all of the monitors from the OBD and start over … sounded drastic, but I was out of ideas, so we said OK, and he disconnected them all. Then, he said, start your car, let it idle with the air conditioner on, and drive it on the freeway for a couple of hours. Hmmm again …

I went home and thought about all of this. None of it made sense. Why not just have monitors that logged in when they were installed? What was the driving about? Clearly, further research was in order.

So I went on the web and found what was claimed to be a “universal driving cycle” that was supposed to integrate all of the monitors and kick them back into action. It was necessary because the monitors need to know what the normal conditions for your particular car are. The claim was that “A complete universal driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.” Sounded good. It went like this:

• Park the car overnight. In the morning, start the car up and let it idle for five minutes so it will be in “closed loop”, whatever that meant.

• Then speed up gradually to 55 mph and hold it there for four minutes.

• Finally, coast to a stop.

Sounded like voodoo to me. Plus, I live at the end of a twisty road in a forest. No way I could get in my car in the morning and immediately accelerate to 55. So I did the best I could. I started, idled, drove to where I could do 55, went through the routine … nothing. There were four monitors not logging in—the monitors for oxygen, for the oxygen heater, for evaporation, and for the catalyst. They were all still giving errors. So I went through the driving cycle again, but without the five minutes idle … and the BlueReader reported that the oxygen monitor came online.

Encouraged, I went through the whole routine again, up to 55 again, coast to a stop. Nothing. No more monitors coming to their senses. Go figure.

Next day, after more research on the web, I found instructions for the universal driving cycle specific to General Motors vehicles including Dodges. Here’s that charming bit of instructions:

To perform an OBDII Driving cycle do the following:

Cold Start. In order to be classified as a cold start, the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen monitor diagnostic may not run.

Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge “No Flow”, Misfire and if closed loop is achieved, Fuel Trim.

Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.

Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.

Decelerate. This will perform the same diagnostics as in step 5. Again, don’t press the clutch or brakes or shift gears.

Zowie, sez I …

So I did the best I could to emulate their special cycle, and after two tries, the oxygen heater monitor woke up and logged in. Great, I thought, this is working, this won’t be a problem.

But three more tries did nothing for the evaporation monitor or the catalyst monitor … grrr. So it was back to the web, where to my surprise I found instructions specific to Dodge catalyst monitors, as follows:

The catalytic converter monitor will not run unless the Check Engine light is off, no pending codes are present, the fuel level is between 15 and 85 percent full, and the coolant temperature is above 70 degrees F. If these conditions have been met, the engine must have run at least 90 seconds, and the engine speed must be between 1,350 and 1,900 rpm. Idle vehicle for five minutes (to reach closed loop operation), then drive at a steady speed between 30 and 45 mph for two minutes.

By this point I was getting frustrated by not knowing what “closed loop operation” was. After more research, I found out that when modern cars start, the fuel-air mixture is determined by factory settings. This is called “open loop” since the car’s monitors aren’t feeding information back to the computer. It’s just running on the hard-wired average numbers set at the factory.

But once the engine gets warmer, the monitors kick in and start sending information back to the computer, closing the loop. At that point the computer can fine-tune the fuel-air mixture based on real-world conditions. This is called “closed loop operation”, because the monitors are sending information back to the computer and thus “closing the loop”.

So … next day, after figuring out how to use my BlueDriver to verify that the car was actually in “closed loop operation”, it was back out on the highway, and to my surprise, after running that specific catalyst driving cycle for only four times, danged if the catalyst monitor didn’t kick in! Pure joy!

Well, not quite pure. That left only the evaporation monitor. The instructions said the drive cycle for the evaporation monitor was the same as for the catalyst monitor, so I ran that drive cycle about six more times … no joy. Head home.

So it’s back to the web, where I find that the evaporation drive cycle instructions part I’d already found were only the first part of the drive cycle for the evaporation monitor … there’s also a second part, viz:

Evaporation: There are two-parts to this test. The first part runs after idling for five minutes, then driving at 30 to 45 mph for two minutes (fuel tank must be half to 85 percent full).

The second part runs after the vehicle has sat for 8 or more hours (cold soak) without being driven. Start the engine and idle for four minutes, then drive in stop-and-go traffic for five minutes using smooth accelerations and decelerations. Stop and idle for 4 minutes. The EVAP monitor should be complete.

I’d only done the first half … and besides, by the time I’d fixed the catalyst monitor and gotten to the evaporation monitor, I had less than half a tank. So, drive to the city, get gas, do some real stop-and-go city driving, come home, park the car. I was hoping the evaporation monitor would come on from that city-type driving, plus the extra miles on the highway … no joy.

Next morning, start and idle. Now, we live way out of town, no stop-and-go traffic, but that’s no problem. I just drove the back roads for five minutes, stopping every thirty seconds or so at imaginary stop lights. Then I idled the engine for four minutes just as the instructions said, and used the BlueDriver to check the evaporation monitor …

Nothing.

However, after working with Jeffrey for a couple of years at People’s Garage, I’ve got Jeffrey’s mindset—when I start fixing a car, that sucker is gonna get fixed, no options, no question.

So I sighed, and I must confess that I said some impertinent and anatomically improbable things about the designers of the Dodge van in general and about OBDII programmers in specific … and I went out to do yet another cycle of stop-and-go driving.

And wonder of wonders, halfway through that drive cycle, the tenth or twelfth drive cycle I’d done over four days, the evaporation monitor finally decided to join the party.

As you might imagine, we took the vehicle to the smog shop immediately, before any of the tiny monitors could change their tiny minds, and it passed the smog test with flying colors.

Is there a moral in all of this? I’d say the moral is the old phrase from the I Ching, the one that says “Perseverance Furthers”. Like everything else in this life, fixing cars is a matter of intention.

Remember, when I started this I knew nothing about car computers. I’d used my BlueDriver once, for a “Check Engine” light diagnosis. I’d never heard of a “drive cycle”. I didn’t know what “closed loop” or an “open loop” was. I didn’t know my car even had a catalytic monitor, nor that there was a specific drive cycle to make the monitor come to life.

All I had was my intention, my unbreakable determination to mess with that vehicle and not stop messing with it until it finally gave up and came to the party. If the first driving cycle doesn’t do it, repeat the same cycle four more times, that’s what it took for our van. Intention is magic. Focus it, stay with it, and there are few limits to what any of us can achieve.

Best wishes to all, offered in my firm and unwavering conviction that we can all realize our dreams,

w.