"Dr. Gizmo"
By Phil Arendt
Two Door Locks Work, Two Don’t
Question 1
The door locks on the driver’s side of my
2004 Audi A4 will not lock or unlock from the remote or with the switch. The passenger side locks work fine.
I checked the fuses in the panel inside the
engine compartment and interior but all the fuses are okay. Is there a module or switch that I can
replace to fix the problem? A.L., email
Answer 1
Guess work might find the
trouble but it is a long-shot. If you
have automotive electro-mechanical skills, are adept at do-it-yourselfer
projects and have the proper tools including wiring diagrams consider removing
the door panel to check power and ground circuits for faults. Since the fuses are okay, more than likely a
switch has failed either in the main control or sensing switch in the
door. It is also possible a wire in the
conduit between a door and door frame may have broken.
Also, it is possible a
control module has failed but without a scan tool to check communication
between modules, activate devices and retrieve and read trouble codes or
program, it is impossible to determine if a module is in trouble.
Repair depends upon your
findings.
Engine Runs Hot Despite
Repairs
Question 2
The temperature gauge in my
2003 GMC Sierra with a 6.6-liter diesel engine is hovering around 240
degrees. I checked the coolant level and
it’s right where it should be. I also
had the thermostats replaced but this has not brought down the
temperature. The temperature rises at
highway speeds. When I’m in stop and go
traffic the temperature drops to the normal range.
This trouble began about six
months ago. At that time the water pump
was leaking. The temperature reading was
not the issue as I made sure the coolant tank was always full. A shop replaced the pump and vacuumed all the
air out of the system so there is absolutely no air trapped anywhere in the
cooling system. When the temperature
rose I returned to the shop and a mechanic tested the gauge and water
temperature to make sure the gauge was okay.
It’s reading fine. In addition
ever since the initial work the temperature of the heater has been lower than
normal.
I suspect something is wrong
with the water pump. What do you think
is causing the trouble? G.N., email
Answer 2
Your suspicions might be on
target. It is possible there is a
manufacturing defect in the water pump such as a loose impeller that may be
causing reduced coolant flow. To find
out for sure the technician who installed it should consider removing it for
examination. If indeed it has a defect,
repairs should be covered under a parts replacement warranty.
Let’s hope this is the cause
of the high temperature readings.
Replacing the pump may be the resolution.
Illuminated Warning Light Is
A Mystery
Question 3
I own a 2008 Dodge Ram 1500
with a 4.7-liter engine and automatic transmission. It has 46,000 miles. I have owned the truck since it was new. I follow the factory maintenance schedule for
all services. The truck is in great
condition.
The trouble is the check
engine light intermittently turns on.
Over the last year and a half I have taken it to three different repair
shops. Each shop found codes that
indicate a problem with an oxygen sensor.
The sensor has been replaced. One
of the exhaust manifolds was replaced and technicians have looked for leaks in
the exhaust system and on the engine.
They have done all kinds of tests but nothing they have done has cured
the trouble. With exception of replacing
the oxygen sensor and manifold I’m told that everything is within
specifications.
Now I’m at my wits end. The light is on. I have taken the truck to yet another repair
shop. I’m told everything is fine. The mechanic has no idea why the light is
on. Can you help? P.D., email
Answer 3
Sometimes there are
conditions that evade logic, but don’t despair.
From your explanation it appears technicians are attempting to address
symptoms associated with fuel trims and oxygen sensors. A close examination of the wiring for the
oxygen sensor circuit is in order.
Perhaps there is a loose pin in a plug.
Maybe there is something on the threads of a sensor that inhibits proper
operation. Something unusual is causing
the trouble. Once the cause is
determined the condition will be repaired perhaps in a matter of minutes.
There is one process for you
to consider. If you have basic
automotive do-it-yourselfer experience, remove the battery cables from the
battery terminals. Secure the cables
tightly together with a clamp, electrical tape or duct tape for about ten
minutes. This will erase learned values
in computer modules. This also will
erase radio settings and other personal settings such as seat and mirror
memories if your vehicle has these options.
Once time has passed, reinstall the cables to the proper terminals on
the battery and drive the vehicle normally.
The powertrain control module that turns on the check engine light will
go through a relearn sequence as you drive.
This procedure is a long shot but may reset values and the check engine
light may remain off until something authentically slips beyond specifications.
Delayed Start Raises Concern
Question 4
For about the last month
when I start the 3.4-liter engine in my 2001 Chevrolet Monte Carlo I turn the
key to start and it may be five seconds before the starter motor activates to
crank the engine. I called a garage
about the trouble. The person who runs
the shop did not have any idea what would cause the trouble. He suggested I bring the car in for
diagnosis. Other than this problem the
car runs fine.
I’m afraid that one day the
starter will not crank at all. Do you
know what causes the trouble? E.S.,
email
Answer 4
This condition is
unusual. There are many possible
causes.
Perhaps the battery
terminals are dirty or corroded. Maybe
one of the bolts on a battery terminal is cross-threaded or loose. Just maybe there is a loose or corroded
ground connection. Maybe a starter relay
has a poor connection or internal fault.
Perhaps the battery has low voltage due to a failing cell or the
alternator is not performing as designed.
Maybe the serpentine belt or belt tensioner pulley is excessively worn
causing the belt to slip a little.
Perhaps there is a fault in the antitheft system or the powertrain
control module has a poor connection.
Maybe the there is a loose connection at the starter motor. It’s also possible the starter motor has an
internal fault.
There are more possible
causes. Depending upon your expertise
you may be able to check for some of these possible causes. If not, consider giving authorization to an
experienced technician who more than likely has all the tools and equipment to
diagnose and repair the condition.
Air Conditioner Fails to
Work After Repairs
Question 5
I have a Ford Freestyle with
an air conditioner that quit working. I
took the vehicle to a repair shop where the mechanic found a leak at a seal on
the compressor. He flushed the system,
replaced the compressor, and charged the system but when he was done, the
compressor did not engage. He performed
many tests but cannot determine the trouble.
He thinks the system needs reprogramming and suggests that I take the
vehicle to a Ford dealer to have the reprogramming work done.
Does this make sense to
you? Why can’t he do the work? What do I do if he made a mistake and the
Ford garage does not want to repair the trouble? N.L., email
Answer 5
Dump the vehicle and
purchase a new Ford. Of course I’m
kidding.
What you explain does indeed
make sense. More than likely the shop
does not have the equipment to program the system. Apparently, they have the equipment to
perform diagnostic tests and activate the compressor to charge the system with
refrigerant but the equipment lacks the ability to reprogram the control
module. I’m surprised the technician did
not provide an explanation. Also, often
an independent shop will provide the service of taking the vehicle to another
shop with advanced equipment.
At this juncture, take your
vehicle to your favorite Ford dealer shop or independent shop that does have
the equipment to reprogram the system.
Perhaps your shop has a business relationship with a dealership or
another shop that can perform the suggested work.
If indeed the shop that
installed the new compressor did make a mistake or the compressor is defective
the shop that installed the part should cover repairs under a warranty policy.
Attempted Repair Fails
Question 6
Recently, the check engine
light in my 2005 Ford Thunderbird has occasionally been turning on. When it is on it feels as though the engine
misfires. When this occurs I can be
traveling at highway speed or in town at slow speeds. It occurs suddenly without any warning. Once it starts I can travel a few feet with
the misfire and light and then everything returns to normal. Sometimes I might travel a mile or two before
the trouble stops. When the trouble
starts the engine feels as though it is running on two cylinders. It runs awful. When things return to normal, I might drive
days without any problem at all.
I took the car to an auto
supply store to have the computer checked.
An employee hooked up a scanner and found code PO2107. He said the throttle actuator was causing a
problem. I replaced the part and had the
computer cleared of codes, but this did not cure the trouble. Can you help?
L., email
Answer 6
First, it would be a good
idea to have the car tested again to determine if the same code has returned or
if other codes have popped up. Address
new codes as necessary. If the original
code has returned more work is needed.
Code PO2107 does indicate
trouble in the throttle actuator control processor or associated circuits. Check the wiring for breaks in the
insulation, poor connections such as bent or loose pins in plugs and for broken
conductors under insulation. While it is
possible the throttle actuator is defective it is more likely you will find the
cause of the trouble in the wiring.
Thanks for all of your great
questions. Dr. Gizmo can’t wait to
answer more.
Phil Arendt is a columnist, consultant and
A.S.E.-Certified Master Technician.
Readers may send questions to Dr. Gizmo at P.O. Box 548, Cary, IL. 60013
or e-mail address drgizmo@drgizmo.ws. 6/29/2012 ® DR. GIZMO © 1989-2012
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