Baby, You Can Drive My Car Now That It's Fixed

The Testing Process

Trying to really pinpoint what was wrong with my car was quite the task.

One thing that was a big help to me was when I noticed that whenever I shook the first connector on the PCM (powertrain control module), I would hear the throttle plate sweep and the vehicle would start communicating once again.

The PCM is pretty much a fancy way of saying engine computer for your car.

Now don’t let those three letters fool you because the PCM plays a very intrical and complex part in all of your vehicle’s various operating systems from something as simple as turning on your ac to something more important such the vehicle’s various transmission controls.

In fact, anytime you hear the word module just think of a series of computers on a network that pass information back and forth to one another. It pretty much works the same way that a network of computers in your home does.

These networks are labeled CAN-B or CAN-C. (CAN is an acronym that stands for Controlled Area Network)

*Note: Newer vehicles come with even more networks then the one’s mentioned.

The fact that every time I shook and held down the first connector everything would work made me believe that there was some sort of short in that area.

One thing, that I have heard Ad nauseum is about how PCMs very rarely fail.

Well, I’ve had extensive experience with different computer-based electronics other the years and my answer to that statement is that it depends.

It depends on the quality of the electrical parts were used in the circuitry and how well it was soldered also.

I watched a video from a guy who specializes in soldering electrical components of all sorts and he said that sometimes they don’t use enough solder when soldering components inside the computer.

He added that the solder must also be at a certain temperature for it to cure properly.

If the solder is not hot enough, it can lead to cold solder joints or breaks in the solder joint which can cause intermittent problems later on down the line.

Now he was referring to receivers which get hot nowhere near as hot as a car engine so you would have to figure maybe something like that figured into its decline.

And computers do fail I might add.

Just look at desktops, laptops or even your favorite game systems. Over time, these items are subseptible to failure.

I’ve had to replace hard drives, power supplies and blown capacitors in power supplies. I’ve had laptops that reach an early electronic grave on account of overheating.

Electrical components inside a PCM are no different. Components such as capacitors and relays can fail over time.

Even with all this knowledge, I still wanted to be sure that it was the engine computer and not something else so I started performing a series of tests to see if I could troubleshoot the electrical issue.

I performed a series of tests on it using a multimeter.

I first looked into the battery.

*Note: I did have the battery checked out by Walmart, which is were it was purchased and I also took it to O’Reillys and they both informed me that the battery was good just discharged. I felt that the battery wasn’t holding a full charge like it’s supposed so I did my own testing on it.

I noticed the battery voltage was really low and having a hard time starting I had a ODB II (onboard diagnostic) scanner my dad had borrowed from a friend that I plugged into the OBD port.

The voltage was sub 12 volts. I believe it was about 11.65 volts or around that so it was extremely low.

This was during the prime of Winter and harsh climates can take a huge toll on batteries especially the ones that may be on their way out.

I ended up taking the battery out of the car completely and hooking it up to a charger and letting it set overnight.

The charger that was used was an automatic charger and it would cut it self off when the battery reaches full charge to prevent the battery from overheating and potentially exploding.

I wanted to see if it would reach a full charge as well as maintain a full charge.

A fully charged battery should read 12.8 volts when fully charged and with nothing attached to it. The battery would get around 12.75 volts and the machine would cut off.

I let the battery sit overnight and the voltage kept going down. I knew then that my battery was on its way to the big O’Reilly’s Auto Parts store in the sky.

I ended up turning it in for a new battery that I wiped clean of all the dust that it had and I gave it good charge.

I only allowed it to get around 13.2 volts because I didn’t want to overdo it. I just wanted to be sure that what I had was good battery which it was.

I also learned a lot about the charger I was using. A good battery should never stop at 12.75 volts.

The voltage should keep going and going up. Now you don’t want to go to high because that would cause the battery to overheat and possibly explode.

There’s 6 cells in a car battery and each cell is 2.2 volts so 2.2 times 6 equates to 13.2 volts so I let it get that high with the charger.

I put the new battery in the vehicle and the problem still existed but I got it started.

I ran it for a bit and then turned it off. I came back about several hours later and I noticed that the battery voltage was still going down. I realized that I had a parasitic drain and that led me to a series of testing.

One of the most crucial questions I learned when diagnosing car troubles is whether or not it’s a no-start or a no-crank.

A no-start is when you try to start your car and you hear something trying to start but it doesn’t.

A no-crank is when you go and start your vehicle and you don’t hear anything which is what I had.

The first thing I learned to do is check for a 5 volt reference which I learned about while watching Scannerdanner videos on Youtube.

I left the link at the bottom of the article if you want to check out his channel.

The 5 volt reference test is pretty much the voltage output that the computer puts out which is usually around 5.02 volts.

I also learned that my vehicle has two 5 volt references: a primary and a secondary.

Since I was dealing with a no-crank issue, I checked both of my 5 volt references and the numbers where right where they needed to be.

After that I knew that I wasn’t dealing with a shorted sensor or a shorted wire in the wiring harness but I still wanted to perform this other test just to be certain.

I performed an IOD (Ignition Off Draw) test which involves disconnecting the negative terminal on the battery and connected one end of your multimeter to the battery post and the other to the battery cable you just disconnected.

You have to make sure that the multimeter is set to read amps. You also need to make sure that all of your switches on your car are turned off completely.

I had a dome light slider switch on slightly which was one of the causes of me receiving high amperage readings in the beginning.

The other cause was from my battery being in the back trunk and lifting up the hatch causes you to use amperage as well so I had to disengage the door so that I could receive an accurate reading.

Once I did all of that and took a reading I found out that nothing was receiving any amperage so everything check out well as far as it being a wiring problem.

Next thing I did was check to see if any of the fuses was open when they shouldn’t be.

The only thing about an IOD test is that it doesn’t test for modules because the modules are not “awake.” They’re “sleep” when you disconnect the battery for the IOD test.

What I did was put the key into the ignition module and turned it to on to awaken all of the modules.

I turned the key off and allowed for adequate time before reading voltage on each of the fuses in the vehicle.

Now the time that it takes for modules to go to sleep can differ depending on what type of vehicle that you have.

I can’t really remember what the timeframe was for my particular vehicle but it was probably around 15 to 45 minutes so I gave it an hour to rest before testing.

Interesting enough, I would this information later about how my car’s modules went to sleep literally right after I took the key out the ignition module.

I set my multimeter to the lowest voltage setting and proceeded to test every fuse in the car. All the fuses went to sleep except one and that was the PCM fuse.

The final test that I did was slowly disconnect connectors under the TIPM (Totally Integrated Power Module).

I disconnected all but except the first one which had the battery positive lead.

I disconnected each of other 5 connectors one at a time and performing a voltage reading after every test.

After every test, I was still receiving voltage from the PCM fuse. The reading would be between 00.1 to 00.9 volts.

Not a lot you might think but it should be reading 00.0 volts just like all of the other fuses.

I made my way over to the PCM. I rubbed my hands against an unpainted metal a few times to get rid of any static electricity I mgiht have before I unbolted it from the frame and placed it on top of the strut.

I followed the same procedure as I did with the TIPM. On a PCM, there are 4 connectors.

Now I didn’t disconnect the 1st one because that is also where the battery positive wire is located along with the power and ground leads.

I disconnected connectors 2 thru 4 one at a time while checking the fuse for voltage between each time.

Come to find out that when I disconnected the 4th connector, the fuse read 00.0 as it should.

The 4th connector is exclusively for your transmission sensors and controls.

At this point, I figured that either the short was in the connector and leading all the way down to all of those other transmission sensors or it was in PCM itself.

I pretty much determined that I wasn’t dealing with a shorted sensor or wire before so it ruled out my first guess.

I even checked the 4th connector itself for any type terminal spread out and to make sure that all the connectors were firmly seated into the slot which they all did.

I checked the pins on the back of the connector and everything was prestine so right then and there I knew that it was the pcm.

Now I know that it’s the PCM, all I have to do is order one and plug it in and I’m done right? WRONG!

If only it were that easy but it’s a little more complicated then that when you’re dealing a lot of these vehicles that in my opinion have an overreliance on the computer.

Unfortunately, these modules have to be “married” to the vehicle. The year, the make and the model, along with the VIN (Vehicle Identification Number) as well the correct mileage of the vehicle have to be programmed into it.

The keys and the win module also have to be programmed to match the “new” pcm.

I put new in quotations because this car that I have is an 08 model and I know that new computers aren’t being made for it so it’s a remanufactuted unit.

That could be problematic as well because sometimes you can get a tomato can instead of a working unit.

And don’t let get started on integrating a new PCM into the security part of the vehicle. If you don’t do that correctly, your vehicle will not run correctly or maybe not run at all.

I read somewhere that you need to have a pin code to program the new PCM to your vehicle so that it will work with your ignition module.

You also have to be a high end locksmith to get access to this code from the dealership. I’ve also heard that you need to program the code you get that very day otherwise it won’t work.

I even heard stories about those codes changing daily. This sounds like a case of these carbuilders doing a little too much.

Another thing was the pricing of one of those things.

If you go to a dealer, you’re probably looking at anywhere from 1500 to 2000 for a PCM replacement job or maybe even more.

The car is 15 years old and the value in a more realisitc era is probably around 6 grand so for that price I would just get another car and be done with it.

The only problem is that we’re not in a realisitc era when it comes to car prices. A new car that came out the same year with the same amount of mileage like mine would probably run around 12 to 15 grand.

Now we know good and well that these vehicles are worth only a fraction of that. Not only is rent too darn high but so are these car prices.

The Solution

A few weeks ago, my brother and I were at the grocery store. He had just finished loading up all the groceries in the hatch where I heard a loud but muffled noise that seemed like it came from the rear axle.

I didn’t say anything to him at first because I had no clue what was going on.

I thought because of all the issues we had with the PCM that it might’ve been a situation involving too much transmission pressure.

He started driving it and everything seemed fine. I asked him how the car felt to him and he told me that it felt pretty well.

When we got it back home, I got down on the asphalt to see if I could see any kind of damage and everything looked good so I went back in the house.

A few days later he and I headed to the bank to take care of some business. I noticed that there was liquid on the ground in front of the bumper.

I thought maybe it was from the rain the other night. We get in the car and make our way over to the bank and take care of some things and then headed back home.

All of a sudden, as we’re about maybe 6 miles away from home, the check engine light comes on and the engine coolant temperature gauge is way over towards the hot side.

We knew right then that we had to hurry up and get this crap home which we were able to do safely without causing anymore harm to the engine.

I popped the hood and I see engine coolant covering the catch pan. I knew then that we had a radiator leak.

I noticed that one of the radiator fans wasn’t turning which explained the noise that I heard a few days ago and also the clanking when we driving the car home from the bank.

Apparently, one of the radiator fans broke off and separated causing damage to the radiator which was the cause of all of the massive leakage.

I remember reading a TSB (Technical Service Bulletin) about that very same thing happening in other vehicles of the same make and model.

I immediately started looking up how you replace the radiator and the radiator fans and how much all of the work was going to cost.

There were many videos stating that the bumper cover doesn’t have to be removed to swap out the radiator but because of the size of my arms, I think that it would be the easier way for me to access the radiator.

Everything would’ve ran about 350 or so after tax. Not a bad price at all but I just didn’t know if I had enough time to do all of this.

Plus, I was still dealing with the same computer issues that quite frankly had gotten a lot of worse of the last year and better.

I didn’t want to further “turn a mountain into a mole hill” so I talked to my father about it.

He told me that he knew a mechanic that we could take it to and I asked how much did he think it would all cost.

He said it would be free because of the insurance my grandmother had took out on it.

We went down to see the mechanic and wrote down my information and he sent a tow truck to pick it up about 4–5 hours later.

To my surprise, this man’s shop could program PCMs.

That was a bit of a shock to me being that many of the mom & pop mechanic shops don’t really handle anything pertaining to electrical problems on vehicles made after 2005.

That led me wondering about how in the heck do those places stay in business.

When it was all said and done, the PCM was finally replaced and flashed with the newest update. The radiator and the radiator fans were also replaced along with the antifreeze.

Everything in all was about 2400 dollars but all I had to pay was 500 bucks for everything so shout out to CarShield.

You never know about these insurance companies. They can be problematic at times when trying to collect from all the money you invested in them.

Everything’s all good as long as you’re paying that sweet, monthly premium but the minute you need to use it, they act skiddish and don’t want to pay for a darn thing.

My grandfather had Traveller’s Insurance way back when and there was a big storm so he filed a claim in.

These people tried their very best to work him but he eventually got them to pay for everything.

*Note: Unfortunately, they kicked him out the insurance afterwards though so go figure.

As far as the car goes, it really runs like a new car now. I did get a check engine light for the P1004 code which has to do with the short runner valve performance.

I’ve been getting that code every so often for the past 5–7 years now though. There was a TSB on how you can fixed that issue without taking the car back to the dealership.

All it said was to remove the short runner valve actuator and spray some carburetor cleaner in those little gears and work it back and forth. That should clean up any carbon buildup in that area.

They have the propensity to get stuck in one place and the srv just can’t activate the valve to open properly.

I did that the other day and all I have to do is clear the DTC (Diagnostic Trouble Code) and everything should be back in working order.

I could disconnect the negative cable on the car battery and that would clear but because of it being a “new” computer, I’m going to allow it to go through more driving cycles before I do that.

I might just use my dad’s OBD scanner and clear the code that way. So far, so good.

One last thing

Before I go, I want to leave a few links to some of the Youtube channels that were very helpful to me in diagnosing electrical problems that were associated with my vehicle.

https://www.youtube.com/@ScannerDanner

https://www.youtube.com/@AutoRepairGuys

https://www.youtube.com/@OnlineMechanicTipsPi