by Sam Dillinger (comments: 0)

Top 5 Questions We Get Asked

Top 5 Frequently Asked Questions

One of the features we have here at www.mycheckenginelight.net is the ability for our customers to email us with questions about their vehicle, and the problems they're experiencing. We get asked questions about the entire spectrum of check engine light issues, as well as other concerns, across the entire spectrum of vehicle lines, from all over the world. I thought it would be useful to everyone for me to make a short list of the most frequently asked questions we get, and some general advice for each.

How Do I Turn Off The Check Engine Light

This is by far the most common question we get asked here (in fact we have a tab dedicated to it here). This is an easy, but deceptive question to answer, because it doesn’t have to be the same answer for every year, make, and model of vehicle. For an older vehicle, think 1996 or so, you can disconnect the battery and reset the check engine light (back in this era some manufacturers had it labeled as the Service Engine Soon light). There are multiple issues with this method, probably the most important of which is the fact that this can really hinder diagnostics. For example: if there is a misfire, and you disconnect the battery while the problem is still present, this will also reset the information the misfire monitor has already learned. When this happens, it will learn the misfire as normal and no longer report which cylinder (or cylinders) are misfiring, which puts you at a big disadvantage for diagnosing the problem. Also, on some vehicles, disconnecting your battery can cause the radio to be inoperative until the factory code is input again. This isn’t a huge deal for everyone, but an inconvenience nonetheless. One last note on this method- on most brand new vehicles, disconnecting the battery won’t turn off the check engine light for most failures.

The best way to turn off the check engine light is with a scanner. For a list of the scanners we recommend click here. The advantage here is that clearing out the Pcode with a scanner won’t reset the misfire monitor, or reset the radio. It will definitely turn off the check engine light, unless the failure is still present, which will bring the check engine light back when the failure occurs again. It’s great for an intermittent condition or just to verify repairs in general. Also, there is such a thing as a Pcode being set once and never again, for any number of reasons.

The final option for turning off the check engine light is quite simple. If the condition that caused the light to come on is fixed, extremely intermittent, or a one time failure, the light will go off by itself after it passes the self testing protocol for that particular Pcode a pre-determined amount of times. This varies by every vehicle and by every Pcode, so it isn’t really much of an option at all.

What Part Do I Need To Replace For (insert here) Pcode

This is easily the next most popular question we get asked here. The reality of the diagnostic information the Pcode represents is that some Pcodes only have 1 cause, some have 2 or maybe 3, yet others still can have 7 or more. In most cases there isn’t an a single part that should be replaced for a given Pcode. The diagnostics should always be followed first because the cause of the Pcode could be a wiring failure or a controller, as easily as it could be a failed component. Repairs get much more expensive if a guess is made and it ends up being the wrong guess! In some rare cases the diagnostics will only give you one repair option, but those are definitely the exception and not the rule.

What Maintenance Should I Do At x Mileage

This is a question I'm always happy to answer for anyone because it’s great to see people being proactive in making their vehicle last as long as they possibly can. The key to that has always been preventative maintenance. The basics are an oil change at every 3,000 miles for organic oil, and every 5,000 miles for synthetic oil. This contradicts what synthetic oil makers recommend (I recommend doing it sooner than they do), but the idea behind preventative maintenance is preventing a system failure. The next one is a tire rotation every other oil change. That’s just a rough guideline to help you remember when it’s time to rotate the tires. If you go a full 10,000 miles between oil changes with synthetic oil, you should rotate the tires every 6,000 - 7,000 miles. Other than those 2 essential maintenance items, you've got air filters, fuel filters if your vehicle is equipped, all the various fluids on your vehicle, brake pads or shoes, spark plugs and wires (if equipped), etc. There isn’t a set mileage for any of these items and all should be replaced based on wear. See our other articles for more specifics on maintenance items.

I Have Pcode P0700 Should I Replace The TCM

This one is a question I get asked very frequently. The check engine light comes on and the vehicle gets scanned, returning the Pcode P0700. Too many people take this to mean that the TCM (Transmission Control Module) has failed. The reality is that this Pcode is informational only and doesn’t indicate any specific repair, or failed component. The PCM (Powertrain Control Module) is the only module that can turn on the check engine light. There are quite a few failures that can occur in the transmission system that will require the check engine light to be turned on, but the TCM isn’t capable of it. So, the TCM sends the P0700 to the PCM to turn the light on. In short it means that the TCM needs to be scanned for the real Pcodes that are causing your troubles, for diagnosis.

Can You Call Me To Discuss My Condition

This question is very close to a tie for the 2nd or 3rd most frequent question I get asked through the website. In the beginning of this adventure I only had email communication with my customers to be of service. After so many requests I’ve decided that adding a way to communicate in real time would be hugely beneficial, as well as being a major function you guys want! Just a phone call won’t be very helpful to either of us. I won’t be able to show anything, hear anything going on, or see anything on the vehicle. I’ve decided to add a Skype calling schedule to our arsenal of offered services, so be sure to be on the lookout for that very soon!

As always if you have further questions or concerns, and if you're looking for advice, make sure to visit us at www.mycheckenginelight.net!

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Meet Sam Dillinger

My name is Sam Dillinger. I've been a professional, dealership technician for 18 and a half years. My first introduction to mechanical repair was when my own vehicle broke down in the fall of 1995. I was 18 and couldn't afford to pay to have it fixed. So I borrowed tools and asked a ton of questions and, eventually, was able to replace the clutch on my truck by myself. During the course of that project, I found that I really enjoyed having a wrench in my hand and figuring out the puzzle of disassembly and reassembly of a motor vehicle.

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