Washing a car with a Sponge

I have heard that you should never wash a car with a sponge. What's wrong with using a sponge? Also, when waxing the car I know I should use a microfiber towel. Is there something about using the Microfiber towel I need to be concerned with?

You should be using a wash mitt such as the one on the left, especially if the car happens to be black in color! The reason is real simple. If you look at a sponge the little pores in it are closed, and as you wash those pores pick up little pieces of dirt. As you go along it becomes like sand paper. Since most people wash in circular motions you will see a lot of dark colored vehicles that have circular, almost swirl marks seen under a light. Use a mitt with a deeper nap for less chance of damage.

Yes, when you use a Microfiber towel, on the corner there is this paper looking tag that gives you some instructions on where it is made, and if you look real close it will tell you to remove this tag before you use it. If you don't, again this Innocent looking tag will scratch the paint of a clear coat paint finish.

Diagnostic Tech: '97 Olds Cutlass Supreme

This Olds Cutlass came in as a no-start. The customer tried to repair the car by replacing the ignition switch but when it still wouldn't start he had the car towed in. I found the battery dead and even if I didn't know someone had been working on the car it was pretty obvious when I opened the driver's door.





I guess the car owner didn't want to waste a lot of time putting things back together in case he had to scrap out the car (grin). You may think that an ignition switch is where the key goes but that is an ignition lock. The actual ignition switch is electrical and mounts to the top of the lower portion of the steering column. In the picture above it is left hanging below the brake pedal. Since the switch has been removed and only one bolt is left holding the steering column in place I can drop the column down and show you what you'll see in the switch mounting area with the switch removed.

The long metal rod is an actuator for the switch. When you turn the ignition lock back and forth the actuator moves back and forth. The end of the rod you see sticking up fits into a slot in the ignition switch. The ignition switch body fastens solidly to the column with two machine screws and when the actuator moves it causes the inner portion of the switch to move creating paths for voltage to operate the various electrical systems in key on, accessory and crank positions.

Since the switch is hanging there so handy I can insert a small screwdriver into the slot and operate the switch using the screwdriver as an actuator.





When I slide the switch to the crank position I should get ignition voltage to the yellow wire at the switch, and I do. But, I don't get starter engagement. The antitheft system on this car uses a small resistor pellet in the key. Even though I'm not using the key to actuate the ignition switch the key must be in the lock cylinder so that the theft deterrent module can read the pellet resistance. If the resistance isn't correct then the module won't enable the starter. The trouble here is that since I already know this I have the key in the lock cylinder and still have no starter engagement.

I have power at the yellow wire when the switch is in crank position. This power should show up at the starter relay fuse #11 in the fuse block. It does and the fuse is good. From the fuse the power should go to the transaxle range switch, through the switch in park or neutral to the theft deterrent relay. Now the theft deterrent relay and the theft deterrent module are accessible (just barely) if you remove the glove compartment. Feel around in the area directly above and you'll find them. There are metal screws to mount them in place. Now it could be that the car just needs a starter and the cranking voltage is reaching all the way to the solenoid. It could be that the range switch is bad and the voltage is never reaching the relay. What I'm going to do though is test the key resistance since all of this wiring is still laying there handy in the column area. If you look closely at the wiring coming from the steering column you will see what first appears to be a large orange wire but if you follow the wire to its connector at the lower end you will see that it is two small white wires covered by an orange sheath. Disconnect those two wires from the car harness and place your ohmmeter test leads on the column side of the harness. With the ignition key in the lock cylinder you should get a resistance reading that matches the resistance of the key pellet. You can measure the pellet resistance directly by placing a lead on each side of the pellet, one on one side of the key, one on the other.

This key pellet measured 1,100 ohms at the key but infinity at the wires. That means that either the lock cylinder isn't reading the key or there is an open in the wiring. Not reading the key can be a bad lock cylinder but it can also be a bad key with the pellet worn too badly to make good contact within the cylinder. There are 15 legitimate key codes, each with a different resistance range. When you take the key to your GM parts department they can place the key into a tester that will check the resistance and tell them the pellet code number. If it is the key that is not good it should show up while trying to read the pellet code. If you know the resistance you can tell the parts person the pellet code number even if the key doesn't read well enough for his tester to show it. There is a chart for this.

Now to verify that the antitheft system is the problem and to give you a better idea of where to find the theft deterrent relay I have removed the glove box and the metal screw mounting the relay so that the wiring can be accessed. The two yellow wires should be powered with the switch in the crank position. They are. The yellow/black wire should be grounded by the theft deterrent module to enable the starter. It is not being grounded because the module doesn't see the correct key pellet resistance.

You could jumper the big yellow wire to the big purple solenoid wire and the starter would engage with the switch or you could jumper a ground to the yellow/black wire and the starter would engage with the switch but the car wouldn't run because there is a fuel enable circuit as well. This is the point though where the rumors are true. If you know the resistance that the module is looking for you can place a resistor of that size in the car harness connector of the two small white wires and the system will allow fuel and starter to be enabled. Another interesting note, the modules are not programmed when new. Each new module will "burn" in to the first resistance measurement it sees on a crank and that will be what it looks for each time.

Since the goal here is a proper repair what I need to do next is remove the turn signal switch. With the turn signal switch out of the way I'll be able to see the two white wires at the lock cylinder. I expect to see one of them is broken. This is very common because the flexing of the wires while turning the key over the years eventually causes a wire to break. Sometimes the break will be inside the insulation and not seen but can be found by carefully pulling on the wires.

I won't go through the procedures for turn signal switch removal. They can be found in any good repair manual. You'll need a couple of special tools. One for removing the steering wheel and one for removing the steering wheel lock plate.

I didn't disconnect the turn signal wiring or airbag clockspring but pulled enough slack to get them out of the way. I can see the broken wire.

This lock cylinder will need to be replaced. I usually cut the connector off at the lower end and pull the wires up through the column. A trip to the friendly GM dealer gets me a new lock cylinder and key with good wiring and the proper resistor pellet.

To feed the wiring of the new lock cylinder down through the steering column I usually run a piece of mechanic's wire down through the column tube until it has several inches sticking out at the bottom. At the top, loop the metal wire to the lock cylinder wire connector, tape it all in place and pull the wire down through the steering column.

After that it is just a matter of putting everything back together. As a plus, the car even starts and runs now!

Kenneth Hayes

AKA Deranger

Why are cell phones banned, while in flight?

I know this does not have much to do with automobiles, but I have heard that cell phones are not allowed to be used during the flight because they might interfere with the navigation equipment. Is this so?

No! They are banned because they might disrupt cell service on the ground. The cellular system is designed to handle calls from ground based surface that are traveling at slow speeds. When operating a cell phone, your call is being routed up to four cell towers at a time. So when your calling from high speeds from the air, hundreds of towers simultaneously are trying to route your call which can play havoc on the cell system and overload the cell network, which can result in dropping calls from people who are on the ground. As a result of this the Fcc has ruled that the airlines ban cell phone use while the plane is in flight.

Diagnostic Tech: '98 Buick Century 3.1

This particular Buick came in with a no-crank complaint. I found the battery to be discharged but after a charge the starter still would not engage. Everything seemed in working order with the key on. The lights all worked. I watched the headlights while turning the key to start and they stayed brightly lit. There was no starter noise, not even a solenoid click. A quick check of fuses with a test light found no problems. I suspected at this point that the car was getting no power to the starter solenoid from the ignition switch.

One of the fuses that tested good was the crank signal fuse. The crank signal fuse is powered from the ignition switch. Put the ignition switch in start position and power should be directed to the crank signal fuse. The power should go through the fuse to the PCM at pin 23 of the C2 (Clear) connector.

Since I had power at the fuse I knew the ignition switch was working. I didn't know if the power was reaching pin 23 of the C2 PCM connector but I also didn't know if I was getting power to the starter solenoid. I only suspected I was not. What I decided to do next, since the starter was very accessible, was to check for power at the solenoid. I clamped a jumper wire to the S terminal at the starter solenoid and the other end of the wire to a test light placed under the hood in a position I could see from inside the car. Since the test light did not indicate power when I turned the switch to start position I knew I had no power to the S terminal of the starter solenoid.

This starting system uses a crank relay. When the PCM sees the crank signal from the ignition switch on pin 23 of the C2 connector the PCM can close the crank relay by grounding pin 76 of the C2 connector. When closed, the crank relay allows the power from the 40 amp crank fuse in the underhood junction block to reach the transaxle range switch. When the range switch is in neutral or park position the power will pass through the switch to the S terminal of the starter solenoid.

This seemed like a good time to connect a scan tool to the car. With a scan tool I might see if there was a reason for the PCM to not engage the starter, such as a problem with the anti-theft system.

Well, there was a problem with communication. My scan tool would not communicate with the PCM. When I have that happen I try to make sure I've entered the vehicle information correctly. The information was correct so I tried to use the OBDII system to access the datastream instead of the GM system but still had no communication. It seemed like a good time to try a different scan tool. The second scan tool didn't help. I still had no communication. I checked for power and ground at the diagnostic connector. There should be battery power at pin 16 and ground at pin 4.

The power and ground were fine. A good class II data line communication can be easily seen with a graphing meter. The class II serial data is at pin 2. Sometimes there is a lot of communication, sometimes less. I had communication activity but I couldn't tell if any of that was from the PCM. There are several modules sharing the class II data bus.

What I could tell is that the bus was operating and there was communication on the line. What I wanted to know next is if I had a good bus at the PCM. The class II serial data line at the PCM is at pin 59 of the C1 (blue) connector. I used the graphing meter to check the data line at the PCM by backprobing pin 59 and I had a good bus. Next I cut the dark green wire feeding pin 59. That would mean that any activity I measured on the PCM side of the wire was coming from the PCM and any on the harness side was coming from another module. The harness side had a good signal. There was no signal from the PCM. I made a check of powers and grounds at the PCM connectors and pronounced this PCM dead.

I left the data wire cut and after connecting a new PCM I had a communication signal on the graphing meter coming from the PCM. I repaired the wire and reconnected the scan tool to look for communication. Success! I had a datastream on the scan tool. A peek at trouble codes gave me P1610 Loss of PZM/BCM Serial Data, P1626 Anti-theft System Fuel Enable Circuit and P1631 Theft System Password Incorrect. I guess the most worrisome part was the car still would not start. The starter would not engage. I suspected the P1610 was related to my having the open wire at the PCM connector and that the two Theft system codes could be handled with a password relearn. I cleared the codes from the PCM and used the following procedure to learn a new password.

Turn the key off, wait at least 30 seconds.

Turn the key to start, just as if you are starting the car, then release the key to run, just as if it had started.

The security light should either be flashing or on steady. Just let it do whichever it likes until it goes out completely. This can take as long as 30 minutes.

Once the security light goes out turn the key back to off and wait another 30 seconds.

Go back through the same procedure, turning the key to start, waiting for the light to go out again. You may have to repeat the entire process as much as a half-dozen times.

The first time you turn the key to crank and the car actually starts you are done.

On this car, the third time I hit crank it fired up. I had to go back into the PCM data to clear any codes that set during the procedure (P1630 and P1631) and then it was outta here!

Kenneth Hayes

AKA Deranger

Using candle wax to stop belt noise

I have heard that if your fan belt squeaks, use candlewax to quiet the noise. Will this work?







Yes, but although the noise will stop, the belts will still slip and cause the pulleys to glaze and the alternator pulley to slip resulting in a dead battery.

Fuel pump longevity

I have heard that running my gas tank low can cause the the fuel pump to work harder to “pull” the fuel through itself, and when the level is low enough, the pump lacks sufficient cooling which can shorten it's life. If this is so, what can vehicle owners do to help extend the life of their electronic fuel pumps?

Maintain a fuel level of at least one-half of the tanks capacity. This may not always be possible, but the more fuel in the tank, the cooler the pump runs.