how to get quality vehicle diagnosis and repair


How to get quality vehicle diagnosis and repair.


Julie was driving home from work to pick up her son from day care, “when the check engine light came on”. That annoying  little red light in the shape of an engine, glaring over the other lights & gauges on her dashboard of her 2014 Lexus GS 460. Thoughts went racing through her mind all at once. Should she pull over right away? Is there fluid or smoke coming out the back? Will the SUV make it to the day care to pick up her son? Is the car safe to drive? Then she looked out the back of the car, “no smoke”, she looked at the rest of the gauges, “all ok” . Day care was a few miles away, Julie continued to the day care to pick up her son. On a slight hill to the day care, the truck began to buck, and that little red engine on the dash started to blink fast!  Carol parked in the day care parking lot, “now what?”  Thinking about the safety of her son, and the four mile trip home, Julie called AAA for a tow.  Kids can not ride in a tow truck, so she called her husband for a ride. At 6pm the tow truck finally came and towed the Lexus to a local shop, which was closed.  They filled out a night envelope, and went out for some overdue dinner now that it was too late to cook at home.

Lexus GS 460 Repair
Engine light diagnosis and repair.


The bottom line is: “We all need our cars to get through life on a day to day basis”, no car means “a messed up day”.

To get quality vehicle diagnosis and repair, you need three things, the correct diagnosis, the correct part in time for the repair, and a qualified technician to preform the repair.

  • How do you get the problem repaired, and fixed correctly, so the vehicle is not down for the count again?
  • Is the Dealer always the best place to go?
  • Do all shops use the factory parts for a quality repair?
  • Could this problem be avoided?
  • Does the technician working on the vehicle know what he is doing?

Cars and Trucks today are some of the most complicated pieces of equipment we use, each year more amenities and safety items are added to next years model.  Modern cars could have up to twenty or more computers on board, all communicating in real time, seamlessly in the back ground. The days of the shade tree mechanic are gone.  THE KEY to a good repair is a good diagnosis- the most expensive part you will ever buy for your vehicle is the one you did not need. A good diagnosis will get to the root of the issue using a pin point diagnostic flow chart, and equipment to test parts and computers.

The Dealer is a good place to get the car repaired, they do have the needed equipment made for that brand of vehicle. The price at the Dealership is most likely high, due to the tremendous overhead at such a big location, you may get a free ride, car wash, rental car, and other things, all included in the high price tag. The repair may or may not come out as planned, all Dealers pay their technicians on flat rate, per job basis. With flat rate, the pay is set for a given job no matter how long it takes, if a one hour job takes half the time -the technician gets paid for the full hour, if the job takes more than an hour, the job only pays one hour. Flat rate makes it so a technician may turn a blind eye to repair he will not make money on (one that would take too much time). That is why so many times a Dealer may say ” We could not duplicate the issue”, as they hand you a list of other items needing attention and $$. Most of the training at Dealerships is online these days, and a good repair comes from a technician that has worked at the dealer for a while, with on-the-job training as they see different items that come in to the shop.

Independent Shop
Independent Shop full of cars, Top Shop Auto

The correct parts for the repair are very important, the OE or manufactures’ parts should be the best. Sometimes an aftermarket or specialty part is made to correct a factory part with a known issue. The vehicle manufactures source the parts to build cars and trucks world wide from a varity of parts manufactures. Good independent shops will buy from the same parts source as the vehicle manufacture, others will try to cut cost by using aftermarket part brands only made for use as aftermarket replacements. Parts prices and quality go hand and hand, if it’s cheap- the part is cheaply made and may not preform as the original part did. Some parts can only be bought from a dealership. Always ask about the parts going in to a repair. Parts can take time to order, an appointment with your local independent shop will help keep your repair timely.

Maintenance on the vehicle will help all the parts last longer. The manufacturer has guidelines to keep the vehicle on the road, most major services follow a 30,000 miles recommendation- 60/90/120/150… (every 30,000 miles). Oil service will very from 5,000 to 7,500 miles, and intermediate services may be needed at each 15,000 mile points. Just look in your owners guide, and/or online to see the manufacturers scheduled service mile points. Other parts can wear out over time and just need to be replaced.  California is a special place, being that it is one of the only parts of the country we can keep a vehicle for 20 to 30 years without the body rusting apart. (Parts only need to be provided from the manufacture for 7 years  past the build date)

Most shops have a set of Master Technicians who diagnose the needed repairs.  Other normally younger technicians, may just do maintenance, brakes, and installation of needed parts while they go to school and learn the ropes.  Most Master Technicians specialize in a few car brands, and can handle other brand repairs, referring to the repair guide as needed. Look for training certificates, and awards of merit for the technicians at the shop doing a repair on your car. Ask if you can talk with the technician, ask about his experience.

If you can get the correct diagnosis, part, and a qualified technician,  all at the time of the repair, no matter what shop you are at, the repair should fix the issue and last.


Quality Diagnosis
Master Technician providing a quality diagnosis with a scan tool.

As for Julie and her Lexus GS 460, a ignition coil had gone bad, causing a miss-fire on #4 cylinder. When the engine light was flashing fast, the problem needed to be repaired right away as not to damage other parts. If driven with the light flashing, Julie could have damaged the catalytic converter with the unburnt fuel from #4 Cylinder. The coil was replaced with a Nippon Denso coil, (the factory brand for Lexus coils). With a quality vehicle diagnosis and repair, Julie drove the Lexus home the following day.


Names and vehicle information have been charged in the story.

Written by Frank Powell, Top Shop Auto, Lafayette, CA

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