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Why Find a Cheap Service Manual 11/09/2011

I am going to give it one more shot at convincing people that a service manual can be worth the $12 it costs to gain access to it. I totally understand that these are bad economic times. But there are some occasions when spending a few dollars can save many more.

Wire diagram from service manual Picture

service manual diagram

I know how it feels to be broke. When the economy crashed in 2008 I was not immediately affected. But now that we are at the end of 2011 I am totally engulfed in the destruction that the crashing economy has caused. I purchased (what I thought was) an affordable home in 2007. It was the cheapest house in town (and crappie). I paid 185K and put 20k into it to make it livable. Now I have abandoned houses on both sides and the house is valued at $55,000. I know what it's like to be underwater.

So when people send me questions and I tell them they should find a cheap service manual they e-mail me back and say... what "do you think I'm rich". I say it's only $12 and they say if I had $12 I could buy a new car. I then tell them that if I had to do this specific repair that I would find a service manual to follow. If I didn't follow the service manual I could do damage to the vehicle and extend the repair time.

Vehicle speed sensor problems 05/31/2011

What car problems will a bad vehicle speed sensor cause? Defective vehicle speed sensors can cause many problems in the computer output control systems. Speed is used by the control module as an input for many systems. If the input is bad the output will not be good either.

Vehicle Speed Sensor

Examples: defective vehicle speed sensors may cause improper torque converter clutch lockup as well as a cruise control malfunctions. A bad VSS can also cause inaccurate speedometer operation. It's really nice to have the vehicle hoisted up on a lift so that the drive wheels can spin freely when you attempt to diagnose vehicle speed sensor problems.

When it is not possible to have a safe way to spin the wheels without moving the vehicle it may be necessary to take the vehicle in for proper diagnosis. There are a few checks that can be made to vehicle speed sensor without spinning the wheels. One test would be to connect an automotive electrical volt ohm meter and get an accurate resistance reading on the sensor.

Car Radio Problems 03/06/2011

A site visitor asked me how to handle his car radio problems. So I decided to write a quick article about how we handled radio problems at the dealerships I worked for. The short answer is we would do some basic checks and then send the unit out for repair if the problem was internal.

First of all the kind of car radios we are talking about would be factory installed units not aftermarket ones. In the case of the site visitor that asked the original question his specific radio problem was poor reception.

When your factory car audio system has this problem there are a few things that you can check. The first thing would be to make sure that the fuses are good. Your owner's manual in most cases will identify which fuses power the radio. Some car manufacturers will use more than one fuse to power the audio unit.

Also note on some factory car radios that there will be an additional fuse in the back of the unit itself. On some models you may have to pull the radio out to gain access to this separate fuse. Another thing that you can check would be the antenna.

Common check engine light problem 12/22/2010

A common check engine light problem that I run into often would be a set code for the evaporative emission control system. Sometimes this code is caused by a loose gas cap. I have also seen defective rubber seals on the cap itself trigger the code.

Please be aware that a gas cap is not the only problem that can set a check engine light code for this system. In fact vehicle manufacturers have actually made it much harder for a loose fuel cap to set a trouble code. But in the end it will still turn the check engine lamp on if it continues to leak fuel vapor.

This page will be about other causes of vapor leak codes. But if you are interested in more information on the loose or leaking fuel cap subject I have put together a gas cap code video that discusses this common check engine light problem. The video outlines steps you can take to correct the issue before spending time and money at the car repair center.

Automotive Heating System Problems 11/22/2010

Automotive heating system problems are usually related to the engine cooling system. Hot engine coolant is diverted to the heater core through some type of heater control valve. The core itself fits inside a plastic case and has an inlet hose and an outlet hose.

stuck open thermostat

In most cases both of these hoses are visible from the firewall on the engine compartment side of the vehicle. The inlet hose should be hot when the engine is at full operating temperature. The outlet hose from the heater core should be warm even when the blower motor is on high and the heat mode is selected. When I have a customer complaint about automotive heating system problems like lack of heat in the interior compartment in most cases I find a problem with the cooling system.

Many times I find low coolant due to a system leak. In some cases a stuck open thermostat can also cause this lack of heat condition. When the thermostat is stuck open all of the engine compartment cooling hoses will be cooler than normal.

Automatic Transmission Diagnosis 11/12/2010

Basic automatic transmission diagnosis should start with some investigative groundwork. Often driver complaints about transmission problems can actually be traced back to malfunctions in other parts of the car.

automatic transmission

You also should take the time before beginning any diagnosis to be sure you know exactly which unit is installed in the specific vehicle. Often technical service bulletins about certain model transmissions can provide a lot of insight on common problems associated with that model.

Knowing the year and model of the vehicle may not be good enough for positive identification of the installed unit. Some manufacturers will perform up grades or even change the models during the manufacturing year. The only positive way to identify the exact one installed in your vehicle is to get the identification numbers off the transmission itself.

Diagnosing Electrical Engine Control Systems 11/02/2010

Diagnosing electrical engine control systems involves much more than accessing the stored trouble codes in the computer memory. As is true during diagnosis of any system you need to know what to test when to test it and how to test it.

Diagnosing engine codes

Because the capabilities of the engine control computer have evolved from simple to complex it is important to learn everything you can about the system the set trouble code refers to before attempting to diagnose a specific problem. Referring to a vehicle specific service manual for this information is highly recommended.

After you have studied and completely understand the system and its capabilities you can then begin your diagnosis using basic and logical methods. I cannot over emphasize the importance of logical troubleshooting. The ability to diagnose a problem that will lead you to the cause of the malfunction and its eventual solution is what separates an automotive technician from a parts changer.

Using logical diagnosis

O2 sensor problems 10/12/2010

On my other blog I recently wrote a post about testing oxygen sensors. My view on the subject is that this is an often replaced in error part. Just because the code sets in the computer does not mean that the exhaust stream sensor should be replaced.

oxygen sensor problems

What I left out of the story and wanted to cover here was that sometimes the emission part simply does need to be replaced. For one thing they will not last forever and if your vehicle has 200,000 miles on it and still has the original part it may be time to replace it for maintenance.

But there is also a situation when the car emission part will definitely need to be replaced. And this is known as oxygen sensor contamination. This is when the emission component is destroyed by a problem with the vehicle.

O2 sensor contamination

How Ohms law Works 09/21/2010

This week I wanted to talk about ohms law since I mentioned it in last week's post about taking the ASE automotive electrical test. Although you may not use this formula while you are solving automotive electrical problems if you plan on passing the electrical test, understanding the law and its principles can really come in handy.

Electrical Circuit

George Ohm is accredited with the term. He was a German mathematics professor and in 1827 wrote a book that included the explanation of how electricity behaved. His thoughts have become the basis for a true understanding of how electricity works.

In his book he states that it takes 1 V of electrical pressure to push one amp of electrical current through a 1 ohm resistor. This equation is the basic law of electricity and is known as ohms law. In a practical example a simple electrical circuit can be connected to a voltage source by conductors better known as wiring.