April 2004 Issue
Issue Summary:
The 341E type of valve bodies used in various Toyota, Lexus and Volvo models look alike but are very different and are not interchangeable.
Before or after an overhaul, a vehicle equipped with the RL4FO3A/V transaxle will not upshift after warm-up.
Nissan Quest/Mercury Villager models may exhibit persistent codes for the throttle-position and/or vehicle-speed sensor.
Ford Motor Co. vehicles with the 5R55N/5R55W can experience delayed or no engagement that is more frequent when the transmission is cold.
Diagnostic Dilemmas
So what is fuel trim? Fuel trim is rebalancing the fuel mixture for reduced emissions. It is a number that represents the computer’s learned amount of total fuel need. That number is derived from the time the fuel injectors are pulsed on and off. The higher the fuel-trim number, the more fuel is being commanded, the more injector pulse-on time. The lower the number, the less fuel is commanded, the less the injector is pulsed on. The fuel-trim command is a result of what the oxygen sensor tells the computer. You don’t want to see short-term fuel trim over 10 on your scan tool. Fuel trim starts at 0 and can go positive (more fuel) or negative (less fuel).
I Lost My EPC!
The AODE/4R70W transmission has a problem with wear in the pressure-regulator-valve bore that can cause a reduction or complete loss of EPC pressure when the unit is hot. This equates to no or minimal line rise, causing the transmission to have medium- to full-throttle slipping in gear and sliding shifts.
Once a pressure gauge has revealed that EPC pressure remains near 0 at any throttle opening (as well as when the transmission is unplugged), the technician usually replaces the EPC solenoid, yet the problem remains.
Making Money with Transmissions and Transfer Cases
At least 50% of the calls on the tech line are generated by shops that are not fully educated in the work they are doing or have not learned to look at the whole vehicle. The modern automobile is a combination of very complex interconnected systems that must function together correctly. Do not let the unit you are working on isolate your thought patterns from the whole vehicle. A knowledge of how these connected systems affect each other is a must for you to remain profitable.
Retirement – Will You Outlive Your Money?
People are living far longer than the Congress and Senate leaders thought they would when they drafted the Social Security Act. Back then people were lucky to reach even 65 years of age. Many were not likely to go beyond collecting their first few years’ worth of payments. Now we live into our 70s and 80s. That’s one reason Social Security is running short of money. Alan Greenspan, Federal Reserve chairman, mentioned in a recent speech that we may have to cut back Social Security or make the retirement age higher. I wouldn’t be at all surprised if people in their 30s and possibly 40s never get to benefit from the program.
Fast, Easy and Simple
It may have taken a while for transfer-case technology to catch up with the technology seen in transmissions, but it has, in fact, arrived and it shows no signs of letting up. The Sport Trac, Control Trac II, Active On-Demand 4WD operation and Progressive On-Demand 4WD operation are examples of the types of computer-controlled transfer cases on the road today.
AX4S or AX4N?
Their turbine-speed sensors look similar but won’t interchange.
At first glance you might think the AX4S and AX4N turbine-speed sensors are the same. However, a closer look will show you that the AX4S sensor is a little longer – which means you easily could install the wrong sensor in a unit by mistake.
March 2004 Issue
Issue Summary:
Mitsubishi’s onboard computer system presents transmission-related “P” codes that are misleading, causing needless, unproductive diagnostic routines and repairs.
The A4AF3/A4BF2 transaxles used in Hyundai Accent, Elantra and Tiburon since model year 2000 are nearly identical to the A4AF1/A4AF2 units they replaced but have some differences.
Solenoid locations, connector-pin ID and bench checks are provided for Mitsubishi F4A-41/42/51 series transaxles.
For the 1995-98 Mitsubishi Eclipse non-turbo 2.0-liter with the Chrysler A604 transaxle, you gain diagnostic access through the Chrysler partition of the Snap-on Scanner’s Domestic Primary Cartridge.
Tips for Transmission-Business Buyers and Sellers
Many of us have reached the age when we are thinking seriously about selling our shops and retiring. At the same time there is a new crop of 30- and 40-something-year-olds who are leaving the corporate world for a variety of reasons, ranging from being laid off or downsized to simply not wanting to deal any longer with the corporate grind. Some are finding their way to the transmission business through brokers who help them locate opportunities commensurate with their abilities and goals.
Fun with Fords
As almost all of us are aware, a technician can easily create a scary nightmare when trying to mix and match parts while making repairs to some of Ford’s automatic transmissions. A classic example of this is interchangeability of the lockup solenoid (LUS) for the 1991 AXOD-E (AX4S) transaxle.
The Tremec TKO Series of Transmissions
The business of doing business for our industry has become much more complicated in the past few years. The general advance of complex designs and electronic functions has made severe changes in the cost and volume of the work the average shop can produce. Add to this the competition for market share that the car dealers through reman programs and the centralized rebuilding centers have placed on the transmission shop, and it is easy to see how the industry is contracting.
February 2004 Issue
Issue Summary:
On a GM vehicle with the 4T65-E automatic transaxle, OBD-II service code P0742, “TCC Stuck On,” can be caused by a sticking TCC release switch on the pressure-switch manifold, a clogged TCC PWM solenoid or a short to ground of the TCC release-switch wire.
A squealing noise from the bellhousing and converter area of a Ford Escort with the F4EAT transaxle can be caused by a clogged pollution-control valve.
