Parlez Vous Francais?

In the year since Superstorm Sandy hit my area. I have seen lots of flood damaged vehicles. They have seem to have come in waves. No pun intended. Right after the storm every other call was a flood vehicle. Then it seemed to die down a bit then picked up early spring and again recently. Every call always starts the same "It was a light flood it wasn't that bad". It usually ends up just the opposite. There were plenty of times I would show up look at the car and leave. I could see the waterline was at the top of the dash yeah light flood, right. The point I stress to shop owners about flood cars is the corrosion you can't see that causes the real issues. The corrosion we see at connectors is easy to see. The corrosion that occurs down the line from capillary action is another story. Salt water or fresh water it doesn't matter.

That being said I have had situations where vehicles had communication one day and not the next day. It is always an adventure. I have has some success stories. Typically, this happens when the shop understands the issues with water damage and changes harnesses instead of cleaning and praying. I treat every flood vehicle the same. First I try to get communication lines up, get the motor running, then get all the accessories going, then finally airbags. It is amazing to see the shops reactions when the vehicle starts and belches out crazy amounts of water and sand from the exhaust.

Here is one such vehicle. It is a 2006 Jeep Grand Cherokee that a shop inherited. He wanted to get it started and determine how far he wanted to go with the vehicle after evaluating how the motor ran. Most of these flood vehicles have no keys or keys that were cut to fit the ignition but not programmed for one reason or another.  That was the case with this vehicle. Key was cut from a locksmith but he couldn't program it. The reason he couldn't program was the wire that feeds battery voltage from the underhood fusebox called the TIPM (Totally Integrated Power Module) to the ignition switch was rotted in the harness. I bypassed this wire temporarily and programmed the key. A few more bypasses and the vehicle started and ran. It poured sand and water out the exhaust. Overall the vehicle sounded well. I opened the drivers door and took a peek inside at the dash and saw this.

    
Was this vehicle from Canada? I am no linguistic expert but this is not English. It is French! I see weirdness on vehicles all the time. But, one thing is for sure Chrysler vehicles that have bad batteries or that have had batteries go low or disconnected for an extended period of time tend to have the greatest number of issues. Some will lose their VIN in modules, they will lose initialization on certain modules, set erroneous codes, etc. This is the first time I saw a language change. Time to break out the factory scantool and try to correct this language barrier.

     
I go into CCN (Cabin Compartment Node) which is the Instrument Cluster. Miscellaneous Functions and choose language preferences.

I update the language from French to English.

Voila!

2004 Lexus RX330

I get a call from a shop concerning a 2004 Lexus RX330 with 143,707 miles. Apparently the vehicle was jump started backwards and was towed in to this shop. The shop found numerous fuses blown. They corrected all the blown fuses and got the vehicle to run. The vehicle did not run well and at this point the shop is thinking the backwards jump start hurt the vehicles PCM. They pulled some codes and then wanted me to come down and either confirm or rebuke their assessment. A little background here. Toyota/Lexus PCM's I have found to be pretty tolerant to backward jump starting. The industry term is "robust". The other item of note is Toyota/Lexus PCM's are very expensive for the most part.

I arrive at the shop and start the vehicle. The vehicle starts and idles fair. Hitting the gas the vehicle stumbles to a stall. I retrieve some codes. Hmmm, all 6 Ignition Coil circuits being bad. We have a common issue. I can't see all 6 Ignition Coils going bad. But, it was jump started backwards. Or, maybe it does have a bad PCM. Let's roll up the sleeves and get some information. My mind right now is thinking we have a power issue feeding the coils. Maybe, instead of the coil primary circuit getting battery voltage it is getting a reduced voltage and that is why we have the codes and the lack of power. I got this vehicle figured out already. Yeah right.

I break out my scope. I know it will give me the most information in the least amount of time. Next is to get the "lay of the land" of what is involved. Knowledge is power so they say.

 

 

 

 

 

Here is a partial wiring diagram of the coil circuits. Each coil has four wires. They have a shared battery power, ground, and IGF. Then there is IGT. Lets go over Toyota ignition systems. IGT is the signal from the PCM to fire the ignition coil. I always refer to IGT as ignition "trigger". IGF is the confirmation signal sent back from the coil to the PCM that the coil has fired and to allow proper fuel injection operation. Now we can setup a battle plan.

My next piece is to know the coil arrangement and the firing order.

Ok, I typically like to trigger off of #1 cylinder. But, #1 on this vehicle is buried under the intake and is a pain to get to. So I will use coil #2, it is easy. I am using Pomona test leads. I absolutely love these for testing. Secure connections, minimal damage to insulation, and well built. I get mine from AESWave.com. These guys are awesome! So the first thing I do is make sure the ground at #2 coil is good using voltage drop. It was. Then I am going to hook my scope up to Battery power, IGF, and IGT signal wires at coil #2 and start the vehicle.

 

Channel 1 in yellow is our battery voltage at coil #2, Channel 2 is coil #2 IGT signal (it is also what I am triggering off of), and Channel 3 is IGF at coil #2. Anything jump out at you? Well my super genius idea of low battery voltage is off the table. Battery voltage is at charging system voltage. I do see something right away.

It looks like we have a Lexus 5 cylinder. I see no deviation in battery power, no IGF signal, and furthermore the IGF signal seems low to me. Typical IGF signal is about 5 volts in amplitude. Lets add some notes. Remember, we are triggering off of coil #2. Remember the firing order.

Adding some notes it fills in the blanks. It is obvious we have issues with coil #1. But, what about that poor IGF signal? I had a theory. My theory was if coil #1 was bad enough it could pull down the IGF signal since this signal is shared amongst all six coils. How could I test my theory? I had an idea.

I reached around and disconnected #1 coil connector and restarted the vehicle. Bingo! Look at the IGF signal. More importantly the vehicle revved up well. It did have a misfire obviously but accelerated well. Let's check those codes now. If my theory was correct I should only have a #1 coil code due to it being disconnected.

Nice! Now I test battery power, ground, and IGT trigger at coil #1 connector. I explain my findings to the shop owner and recommend an OE coil unit for #1 cylinder. The unit was installed and the vehicle delivered.

To program or not to program

Part of my service is module programming or flashing some people call it. Module programming is steadily increasing as more and more modules show up in todays vehicles. Reprogramming can fix many issues but reprogramming should not take the place of good diagnostics. When I am called in to do a reprogramming I always want to know why does the shop want to do a reprogram. Many times I am called in to a shop who thinks there has to be a reprogram for the problem they are experiencing because they have exhausted all other avenues. They have changed parts-sometimes many times, checked wiring, and now they are at wits end. Here is an example. This shop has a 2004 Toyota Rav4 with 131,629 miles on it. The vehicle flagged a P2238 code related to the Air Fuel Ratio Sensor. The shop diagnosed a bad A/F ratio sensor and did a TSB search and noticed there was a PCM upgrade for that code. Toyota like most manufacturers has specific TSB's for reprogramming. In other words reprogramming is TSB driven.

Here is the aforementioned TSB. I always review TSB's thoroughly. I always make it a point to try whenever possible to get the TSB from the manufacturers website as well. Reason for this is they have the latest information. Maybe, there was a change in procedure, etc. Using the manufacturers website information assures me of the latest and greatest information. I also scan the vehicle as well with my tooling. It is not that I do not trust my customers. It is just assurance that we are going in the right direction. It also gives me an opportunity to see if we have other issues.

 

 

 

Ok, here we have it. The next procedure is to see what calibration is currently in the module. Then compare it to the TSB information.

It is the old calibration that needs updating. Normally, I use Toyota Techstream to program. This shop had sketchy internet and the calibration I needed I had on a Toyota Calibration CD. Toyota no longer uses Calibration CD's. Like most manufacturers it is all web driven. I will have to get out my J2534 reprogramming equipment. I am not a big fan of J2534 programming. I like to use factory tooling. In this case I felt confident using it.

 

 

Here is a laptop with proper software loaded on it and the J2534 interface. It is important to use an approved interface. All manufacturers will list them on their websites.

 

 

Here is another essential tool for programming whether it be J2534 or factory tooling. A battery maintainer. This one is the Midtronics PSC-550. It is pretty much the industry standard. It carefully maintains battery voltage at 13.4 volts with no ripple that you would get from a regular battery charger. The process of programming is menu driven. You have to pay attention! Key cycles have to be done in the allotted time. Let's begin. This flash took about 14 minutes.

 

 

 

   This is the after screen showing the previous calibration and the new calibration. It also shows that it was successful. Like anyone in my business it is not successful until it starts and runs. Most importantly it solves the concern.

 

 

 I check for codes after we start and run the vehicle. Looking good so far.

 

 I always check if the calibration was really updated.