Showing articles & questions for topic
diagnostics

Related articles

How to Know When to Replace Car Tires
Car tires get worn out after miles on the road. Inspect tires for damage and check tread depth with a coin to make sure car tires are in good shape.
How to Diagnose Your Car's Air Conditioning System
There There is never a good time for your air conditioning in your car to stop working, but it typically seems to happen in the dead heat of summer. If your AC system has either quit working or has stopped...
How to Diagnose a Cooling System Problem
You may be driving down the road or sitting at a stop light when you first notice the temperature gauge in your...
How to Troubleshoot a Gas Cap That Won't Come Off
Gas caps stick and won't come off when the gas cap is broken, there's a mechanical defect in the gas tank filler neck, or gas cap is locked.
How to Troubleshoot a Gas Cap Cover That Won't Open
Gas cap covers, or fuel doors, get stuck closed and won't open if there's a faulty internal spring or lever, lack of lubrication, or bent fuel door.
How to Troubleshoot a Clutch Pedal Sticking to the Floor
Clutch pedals in manual cars stay on the floor if there's a failed clutch release bearing, slave cylinder, clutch master cylinder, or clutch linkage.
Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?
If If your car was manufactured after 1996, it has an OBD II system that monitors emissions and other systems on board. While it’s primarily focused on emissions, it can also report other problems that are only peripherally related to...
Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?
If If your car was manufactured after 1996, it has an OBD II system that monitors emissions and other systems on board. While it’s primarily focused on emissions, it can also report other problems that are only peripherally related to...
How to Troubleshoot a Power Moon Roof That Won't Open
Car moon roofs won't open if the tracks are clogged or the cables, electric motor, or moon roof switch is broken.
How to Troubleshoot a Parking Brake That Won’t Release
Emergency brakes won't release if there's a damaged parking brake, return spring, rear caliper pivot arm, or a caliper with a stuck piston.
Should I Buy a Bidirectional Scanner?
Automotive technician jobs require mechanics to use bidirectional scanner to take as well as input information when diagnosing car problems.
10 Best Automotive Scanners
Automotive scanners are a great tool to get quick diagnostics on a car. The Donop Professional U480 can help you troubleshoot issues on the road.
How to Diagnose Your Car Problems If You Know Nothing About Cars
Learn how you can diagnose car problems like engine issues without using diagnostic tools or any prior knowledge about cars.
How to Test Your Alternator
Having your alternator fail can leave you stranded on the side of the road. Though it is not necessary to know every aspect...
How to Troubleshoot Car Overheating Causes
Car overheating can be caused by low coolant, a faulty radiator fans, a broken serpentine belt, or a stuck thermostat. Stop driving an overheated car.
Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?
If If your car was manufactured after 1996, it has an OBD II system that monitors emissions and other systems on board. While it’s primarily focused on emissions, it can also report other problems that are only peripherally related to...
Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?
If If your car was manufactured after 1996, it has an OBD II system that monitors emissions and other systems on board. While it’s primarily focused on emissions, it can also report other problems that are only peripherally related to...
I Have No Idea What's Wrong With My Car - Where Do I Begin?
Any driver can use their senses to diagnose a car problem. Use your sense of smell, touch, and hearing to figure out what's causing the issue.
How to Troubleshoot a Small Engine Problem
Small car engines need attention if the car won't start, there's a loss of power, the car stalls or overheats, or if the car backfires.
How to Troubleshoot a Parking Brake or Emergency Brake That Won't Hold the Car
Emergency brakes won't hold a car if the parking brake level is stuck, the parking brake cable is stretched, or the brake shoes or pads are worn out.

Related questions

What Is an ECU and What Does It Do?
The electronic control unit (ECU) used in today’s cars and trucks is used to control the engine and other components’ functions. An ECU is a computer with internal pre-programmed and programmable computer chips that is not much different from a...
No start
If Diagnostic Trouble Codes were downloaded, those codes would really would be key to advising you. If there is no spark, obviously all ignition system components are possible suspects but if the coil(s) and spark plugs are new, the crankshaft...
Loss of power under acceleration
Hello, thank you for writing in. The components you have checked thus far have been valid steps. You want to go through system by system, and make sure the engine is getting what it needs. Start with the fuel system,...
Check Engine Light
If your vehicle's check engine light (https://www.yourmechanic.com/article/what-does-the-check-engine-warning-light-mean-by-spencer-cates) illuminates, there is a malfunction that should be diagnosed and repaired. If the check engine light is flashing, that means there is a serious fault, such as cylinder misfiring, that requires immediate repair....
A/C problem
There are innumerable things that can go wrong with the A/C system and so the best thing to do is request an air conditioning system inspection (https://www.yourmechanic.com/services/ac-is-not-working-inspection) and the responding certified mechanic will get this resolved for you. The possibilities...
Can I turn off the SES Light ?
The purpose of the SES light is to alert you that there is a malfunction in the engine or powertrain. When the SES light turns on, you can attach a code scanner to the vehicle's OBD-II port under the steering...
My engine light turns on, and i went to autozone to diagnosis, and it's faulty o2 sensor. Would you be able to replace it?
If code P0136 (https://www.yourmechanic.com/article/p0136-obd-ii-trouble-code-o2-sensor-circuit-malfunction-bank-1-sensor-2-by-jay-safford) sets the only way you can determine if the oxygen sensor has failed is to use an automotive scope to graphically depict the sensor output waveform (it will look roughly like a sine wave) and switching...
Does the Mechanic verify the replacement part I think I need is what a actually need?
If you call out a mechanic to install a part that was diagnosed by another company then to answer your question is no. The mechanic that is to install a previously diagnosed parts cannot in most cases verify the part...
Is diagnostic fee applied to repairs
The diagnostic service fees are not included in the service call. If a diagnosis is needed to find out the problem then the mechanic needs to be compensated for their time to do the diagnosis service.
I have a Po171 code on a 2006 trailblazer
The cause behind diagnostic trouble code P0171 (https://www.yourmechanic.com/article/p0171-obd-ii-trouble-code-system-too-lean-bank-1-by-andrew-quinn) is easiest to find by looking at the secondary firing patterns on the Bank one cylinders. That will confirm if the too lean condition, that has caused the code to set, affects...
Truck won't turn over
The battery should be load tested by a professional. Load testing can only be reliably performed on a fully charged battery. If the battery passes a load test be sure it is NOT a marginal pass in which case you...
Need car diagnosed.
I would call YourMechanic to come and diagnose this problem.
Engine light on with P0171 code
The cause behind diagnostic trouble code P0171 (https://www.yourmechanic.com/article/p0171-obd-ii-trouble-code-system-too-lean-bank-1-by-andrew-quinn) is easiest to find by looking at the secondary firing patterns on the Bank one cylinders. That will confirm if the too lean condition, that has caused the code to set, affects...
ABS and brake light is on
If the ABS warning light is on, that means that there are downloadable ABS diagnostic trouble codes, much like the codes you would download if you have a Check Engine Light diagnostic (https://www.yourmechanic.com/services/check-engine-light-is-on-inspection). The ABS trouble codes will give a...
I have a 2000 honda civic EX and check engine light with D4 blinking ... and pulled the codes p1705 and p1768 ...
Trouble code P1705 implicates the throttle position sensor (TPS). A transmission fault (which is indicated by a flashing "D4") can arise if the TPS is malfunctioning. Consequently, I would recommend testing the TPS first. Once code P1705 is resolved, then...
I have a 2002 chevy avalanche z71 it won't move forward in any gear,but it will move in reverse
Check to see if any diagnostic trouble codes have been stored in both the PCM and TCM. Check the fuses in the circuits that power the transmission controls. Occasionally, a short in a sensor such as an oxygen sensor will...
voltage warning light still coming on 30-45 seconds after car starts.
Nothing should be replaced until you have in hand a definitive diagnostic pinpointing the faulty segment of the car's electrical system. There may be too much voltage drop in the charging circuit, as well as elsewhere, but start with the...
Car won't start key turns and lights dim when it cranks. I just don't hear a buzzing sound from the fuel pump when turn key to on
Code U1100 signifies a communications error which is either a module fault or a deficiency in the wiring harness between communicating modules. There's a possibility that a dying battery is a cause of such a code (and a cause of...
my 04 sentry has the service engine light on.
If your vehicle's check engine light (https://www.yourmechanic.com/article/what-does-the-check-engine-warning-light-mean-by-spencer-cates) illuminates, there is a malfunction that should be diagnosed and repaired. If the check engine light is flashing, that means there is a serious fault, such as cylinder misfiring, that requires immediate repair....
how do i know if i have an bad PCM
PCM's are usually replaced at the end of a "process of elimination". That is, with most engine management control failures, there are a whole host of common causes that are evaluated first. Once that long list of most common causes...

Need a mechanic?

Our certified mobile mechanics make house calls in over 700 U.S. cities. Fast, free online quotes for your car repair.

Get a quote