Hi guys. I'm following this to learn the solution. To speed things up a fuzz, allow me to comment on scanners.
Joe is referring to a scanner as used by all mechanics. This is not a simple fault code reader as is used by the people at most auto parts stores. Some of those, along with some, ... What are called "scanners" can read live data but they update extremely slowly, often to the point of being of little value with intermittent problems. If the tool costs less than a few hundred dollars, it's not what Joe is referring to.
My scanner of choice for all of my vehicles is Chrysler's DRB3. They were available through the manufacturer's web site for $6200.00 for the complete kit. You can find these used on eBay today for around $2000.00. Depending on the year they were manufactured, they will work on Chryslers back to '96 or '98 models with nothing extra plugged in, so they will work on your truck. The first year they went obsolete was on 2004 Dakotas and Durangos. The last models they worked on were some 2008 Jeep models.
There are extra plug-in cards that can be used for other models. One is the "Supercard". That allows the scanner to work on all Chryslers back to 1983 models up through 1993 models. The "Supercard 2" allows it to work on '94 through '97 models. In addition, it will allow you to do emissions-related work on all car brands and models starting with '96 models when they all switched to a common OBD2, (on-board diagnostics, version 2) emissions system. For that reason, a lot of independent repair shops bought them. Since they have all invested in something newer by now, many have old DRB3 s they would probably like to sell. I sell replacement cables and the Supercards at the Iola Old Car Show swap meet every summer for over $200.00 ea. You can find them for considerably less now on eBay. There are a few other specialty cards available such as for the Crossfire, Sprinter, and a version of the Stratus / Sebring, but you don't need any of those cards for your truck.
You will also find good deals on Chrysler's older DRB2, but that won't work on your truck. They require a plug-in cartridge for each specific models year, and for specific older models. The cartridge label colors match the color of the service manual covers for that year. The last one had a yellow label for the '94 model year that combined all of the previous cartridges into one. That is the only one that is needed for every model, and it is used for '95 models as everything is the same.
For those who have older models that can use the DRB2, I also have a Monitor 4000 aftermarket scanner. They are almost identical to the DRB2 and they use cartridges, but in a different way. Both the DRB2 and the Monitor 4000 were made by OTC, but the Monitor 4000 works on GMs, Fords, and Chryslers with one cartridge, up to the model year listed on the label. I also have a specialty anti-lock brakes cartridge but have never used it, so I can't speak to that. These aftermarket scanners usually work on more models than the factory scanners, but they never do quite as much on any one model.
Because my 2014 Ram is too new for my DRB3, I bought a used Snapon Solus Edge on eBay. The seller has a few listed all the time with the latest updates. I became familiar with these from using my friend's at his shop. The problem with these is Snapon is very proud of their updates and charge accordingly. I've heard as high as $1000.00 per year, but this can work to your advantage. A new model costs in the area of $4000.00, but it only covers domestic models. You have to pay extra for Asian import coverage, and still more for European coverage. There are a lot of additional cable adapters for the '95 and older models but I don't know if those are included with those packages. One of them includes Harley Davidson, and I think there's an additional optional package for large trucks.
I bought mine in 2018 with the latest update for $1800.00. There were plenty of others out there for as little as $700.00 updated to around 2012 to 2014. That is all you need for your truck, but it doesn't pay to update them any further. That's what makes them a really good value for you. When updating, Snapon won't let you skip any years. In my case that means if I want to update mine to cover 2022 models, I have to buy the 2019 update before I can buy the 2020 update, then I can buy the 2021 update, etc. To try to update one that is current to 2014, for example, would cost a lot more than just buying a brand new one. That's why they lose their value to shops that work on the latest cars.
You might also consider a scanner by Autel. You'll find them at any Harbor Freight Tools store. The advertising looks appealing as they claim it will do everything my Snapon will do, but for a much lower price. I've never touched one, so you'll need other opinions to make a decision. I've heard good things about them.
I mentioned earlier that some of the inexpensive code readers will display live data, but they are really slow. I bought one for my cousin, and while it did indeed show sensor values, when we did a "throttle sweep" to watch for dropouts or glitches, it took two or three seconds for the display to update. That made it too painfully slow to be of use for that purpose. To just see if a sensor was reporting the right value, it worked okay for that, but for the average user, the money would be better put toward a real scanner.
Most scanners including the DRB3 and the Solus Edge have graphing capabilities too. That allows you to watch four values over about a 20 second period of time and watch for dropouts or changes that occur too quickly to see on normal value displays. These all read fault codes in all of the dozens of computers on today's vehicles. The Solus Edge also allows you to select a fault code by number, then read the diagnostic steps to solve it. If you use the DRB3, Chrysler produced hundreds of specialty diagnostic manuals covering the various systems on different models. The advantage to those is they show every pertinent connector and exactly where to take a reading, along with wire colors, for every step of the diagnosis. They lead you through the chart without having to know anything more than how to read a voltmeter. You don't have to know how the circuit works to get through the charts.
What Joe is asking is if signals are showing up from the crankshaft position sensor and the camshaft position sensor. When they do during cranking is when the Engine Computer turns on the automatic shutdown, (ASD) relay. That relay sends 12 volts to the ignition coil(s), injectors, oxygen sensor heaters, alternator field, and fuel pump or pump relay. The DRB3 lists both sensors with a "No" or "Present" during cranking. You're looking for one that stays on "No". Even when it does, there may not be a diagnostic fault code related to that. The computer often needs more time to detect the missing signal, as in when a stalling engine is coasting to a stop. You don't want to disconnect the battery or let it run dead as that will erase any fault codes, then that valuable information will be lost. A cam or crank code may not set again just from cranking. That's why Joe needs to know what the scanner shows for those sensors, and it's why a scanner is needed for that.
Joe also alluded to your dandy observation that heat and time are variables in this problem. That is exactly how the cam and crank sensors commonly fail, by becoming heat-sensitive. Typically they will remain cool and working as long as the vehicle is moving. Once you stop for a short time, as in when stopping for gas, natural air flow is gone. That allows engine heat to migrate up to the sensors, causing one to fail. They usually work again after cooling down for about an hour. This can go on for weeks or months before becoming a permanent failure.
For my last comment of value, be aware that fault codes never tell you to replace a part or that one is bad. They only indicate the circuit that needs further diagnosis, or the unacceptable operating condition. When a sensor or other part is referenced in a fault code, it is actually the cause of that code only about half of the time. First we have to rule out wiring and connector terminal problems, and mechanical problems associated with that part before we spend our customer's money on that part. This is why very often you'll read where someone replaced a part two or three times and the fault code keeps setting over and over.
Joe will add more information on scanners when he gets back. He will get you to a solution.
Tuesday, November 15th, 2022 AT 1:26 PM
