This video is dedicated to helping you locate the cause of your no-start. The video outlines five common causes of an engine light on with a no-start condition and by the end of this video, you’ll have a good understanding of where to begin fault-finding.
You’ll find other useful resources on this page, tips, links to tools, parts, and supplies required to troubleshoot and complete common repairs to various engine systems.
No start Common Causes
Here we’ll look at each of the common causes of no start in a little more detail, I’ll give you the inside track on how to approach the diagnosis of each.
Reading Fault Codes With Code Reader
Since we have a MIL (Malfunction Indicator Lamp) also known as “Engine light on” we should begin with that useful piece of information. Of course to do that we’ll need a code reader. I’ve included a link below to a useful inexpensive code reader the Topdon which I wrote a post on previously you can check that out here “Topdon vs Autel”.
Locate DLC – Reading codes is a simple task, locate the Data Link Connector (DLC) usually under the driver’s side dashboard but older cars like to hind them in some hard-to-find places. The most common places include under the driver’s dash area, in the passenger glove box, inside the fuse box, below the center console panel, or ash tray. If you’ve exhausted these reach out to Google and you’ll find the answer.
Read Codes – After plugging in the code reader you’ll need to turn the ignition to position two (ignition on) this powers up the code reader and allows it interrogate the PCM (Powertrain Control Module). After that, reading codes is easy, follow the onscreen menu – hit “Read codes”.
About thirty seconds later you’ll get a fault code(s). That code as you know is related to a fault or faults detected by the PCM. Since the engine light is on we know there will be a hard code logged.
Having a symptom and an engine light is a good thing, it’s not uncommon to have a symptom without an engine light or fault code.
Sources of Information
With code in hand now you’ll need to make sense of it. Here’s the fastest way to make sense of your fault code.
Google – Google is your best resource once you have the code. Inputting your year and model car with the fault code will likely have you well on your way to getting to the bottom of the cause. You’ll also get a feel for how serious, difficult and expensive the repair is.
Car Club Forum – There’s a club for every make vehicle on the highway and that’s useful, the members are a great bunch too. They love the brand and most just love to help a fellow owner out by giving them the benefit of their experience.
The most common cause of a no-start is a battery fault. While a flat or faulty battery in older cars emits an audible click..click…click when you hit the key. Many modern cars don’t, especially high-end modern vehicles. They employ a battery control module (computer) dedicated to maintaining battery health.
If battery power is insufficient (faulty or just flat) the battery control module won’t allow the starter to crank the engine. It may however set the check engine light (MIL).
But even if your vehicle does crank, it may not crank over fast enough. Many vehicles require a min crank spend in order for the crankshaft sensor to register engine rotation. More on this later.
For now and without knowing what the engine code is, it is a great plan to check the battery health.
Jumpstarting – As an alternative to running checks on the battery, since time is money to most folks, attempting to jump-start your vehicle is a great elimination test. If your vehicle starts after a boost, you know you have a battery issue. You’ll find a jump-starting video here, it covers identifying battery terminals and the actual jump-starting process.
Jumpstarting sequence as follows: add cables in sequence 1, 2, 3, and 4. Remove them in reverse order 4, 3, 2, and 1.
Battery Checks – A very common and easy to fix battery issue is loose or dirty battery terminals. Loose and dirty terminals prevent the free flow of power to the vehicle’s electrical system. Before testing battery health the terminals must be clean and tight.
You can use a battery test tool or a voltmeter to test a battery. A test tool is more reliable and easier to use. I covered battery testing using the Topdon battery tester and you can check that out here “Best battery tester for home use”.
The fuel pump is located in most vehicles inside the gas tank towards the rear of the vehicle. Its job is as you guessed to move gas from the tank to the engine, no gas means no start. The pump on most vehicles emits a buzzing or humming noise when the driver’s door is opened or ignition is turned to position two. Scanning for fault codes you may find a fuel rail pressure low code P0087.
The buzz or hum is the pump preparing the fuel system for start. It’s building pressure inside the fuel rail ready for the injectors to dispense.
We can use the knowledge of this buzzing noise to our advantage. If when opening the door or ignition in position two, you don’t hear the pump operation, you may have found your problem. A mechanics hack – banging on the bottom of the gas tank (use something soft like wood) may cause the pump to start momentarily. That’s a sure sign your pump is faulty.
Most ignition coils live on the engine topside just over the spark plugs. Their job as you may know is to create high voltage and feed it to each spark plug sequentially. When a coil fails, and that’s common, it causes the engine to misfire (not fire one of the plugs) in addition the engine light comes on.
Many modern vehicles use an independent coil on each spark plug known as COP (Coil On Plug). If your vehicle has this type of coil configuration, then it’s not likely a coil is a reason your car is not starting. A car will still start even if one COP fails, it will still set the check engine light though.
COP isn’t the only type in use, many vehicles still employ a coil pack. A faulty coil pack may very well cause a no-start and set a check engine light.
Common coil fault codes include P0351 coil circuit fault and misfire codes P0301 – P0312.
The MAF (Mass Airflow Flow) sensor is a sensor located in the air intake trunking upstream of the air filter. Its job is to report air volume to the PCM (powertrain Control Module). This is important information as it is critical to correct fuel ratios.
MAF sensors work hard and although the air that passes over the sensor is filtered it still contains small contaminates. A dirty MAF is common so too is a faulty MAF. Incorrect readings cause a range of symptoms from bad gas mileage to a no-start.
Common codes associated with a faulty MAF include – P0100, P0101, P0102, P0103, P0104. But bear in mind a code isn’t always set instead you may get a system too rich or lean code.
Below you’ll find MAF sensor cleaner and throttle body cleaner conveniently delivered to your door by Amazon.com. Picture links out to Amazon.
The crank sensor is important, sometimes referred to as the CKP sensor. It’s located at the crankshaft, either the front of the engine behind the harmonic balancer or at the rear at the transmission bell housing. The crankshaft sensor is tasked with identifying crankshaft rotation, this information is required to begin the process of starting the engine. The PCM awaits this signal before it initiates the fuel pump and ignition coil operation.
A faulty CKP means nothing is going to happen. CKP lives in a pretty unhospitable space and is prone to failure. Common CKP failure codes include P0337 (low voltage) and P0335 circuit fault.
Tools and Parts
There’s never a good time to break down but when it happens it’s better to be prepared and that begins with tools. It’s not practical to haul a full toolbox around, but I have found it’s surprising what you can achieve with just a few MacGyver-type tools in the trunk.
Anyway below you’ll find a ton of useful tools and supplies to help you solve your no-start.
The NOCO jump starter pack is a serious tool, don’t let its size fool you. This little guy fights way above its weight. Capable of starting a diesel truck engine and yet small enough to fit in your glove box.
It features smart design and technology, it won’t allow you connect it backways and it features a no spark technology, meaning it doesn’t arc when connected to the battery, nice!
It’s powered by latest technology lithium battery. But it’s got a few more tricks, it’s a fast charger too (2 hours), that means you can use it to charge your car, truck, boat, mower, snow blower battery as well as jump start them.
Other features include – a charge port for charging your phone or iPad, comes with a eight mode hand lamp (500 lumens),12v 15amp port to power air pumps or whatever.
It’s first on the list because without battery power our car is going nowhere. Finding somebody to give you a boost isn’t usually a problem, but not having cables is. The Cartman 20ft booster cable is a good quality set of jumpers that will work when you need them.
Copper coated alligator clips for enhanced connectivity and a coinvent carrier bag for neat trunk storage. You’ll never need another set.
PT Stubby set is perfect for emergency repairs, small enough to stow in the trunk. It covers all the basics, a ratcheting driver with bits set. An adjustable wrench and a ratchet set with Metric and standard sizes. An adaptor 1/4 to 3/8 makes it a versatile set.
I can’t work without a good light, if I don’t have good light I find the job goes down hill quickly. Enuotek build this tough mechanics light, I’ve had several of these lamps, not because they break but because I lose them.
I’ve bounced mine on the ground so many times, and it survived. They are a real MacGyver of a lamp, magnet, hooks, led area light and spot light.
- About the Author
- Latest Posts
John Cunningham is an Automotive Technician and writer on Rustyautos.com. He’s been a mechanic for over twenty-five years and has worked for GM, Volvo, Volkswagen, Land Rover, and Jaguar dealerships.
John uses his know-how and experience to write fluff-free articles that help fellow gearheads with all aspects of vehicle ownership, including maintenance, repair, and troubleshooting.