Diagnosing Transmission Problems
Figuring Out the Fuso

We have had some confusion on the ATSG help lines in reference to 1999 and later Mitsubishi Fuso tilt-cab medium-duty trucks equipped with the Aisin Seiki.

The first problem is, how do I get codes out of these trucks? Since aftermarket scan tools do not communicate with these trucks, data is not available and code retrieval must be done via the flash-code method. That means that a certain procedure must be performed, after which a light somewhere on the dash will flash a code pattern. The illustration in Figure 1 shows the locations of the diagnosis switch and the memory-clear switch, both of which are single-pin connectors.

Coolers and Contaminants

Most of us have been battling cooler and contamination issues for years. We may not realize it, nor care to look for it, but it does manage to rear its ugly head.

First we need to look at the sources. Mike Steen (technical director at Certified Transmission) has spent considerable time on finding these sources. Along the way, I have found a few as well. Hung valves and stuck governors have plagued us for years. We thought the contaminants came from coolers. We bought flushers and flushed coolers, and the problem went away – well, not quite. We still have problems.

The 4T65-E: ‘Slip-Sliding Away’

Three to six months after you overhaul a 4T65-E transaxle, the vehicle may come back with a code, either P0730 (incorrect/undefined gear ratio) or P1811 (maximum adapt and long shift).

Generally, code P0730 occurs immediately after installation of a transaxle with an incorrect ratio. This could mean that either an exchange unit with an incorrect ratio was installed or incorrect sprockets and/or final drive was used during rebuild in the shop.

August 2003 Issue

Issue Summary:

Vehicles equipped with the RE4RO1A transmission may exhibit a 2nd gear start, with no first or fourth gear.

Mitsubishi Fuso trucks have a diagnostic lamp that will flash if the automatic-transmission control unit detects a fault. We cover procedures for retrieving and clearing codes on 1988-94 and 1995 and later models.

July 2003 Issue

Issue Summary:

On 1996 and newer Dodge and Jeep vehicles, deteriorated PCM connectors can cause a variety of diagnostic trouble codes.

Ford Escort/Mercury Tracer sedans have experienced a condition in which the transmission operates properly until the headlights are turned on, at which time the transmission is stuck in third gear and remains there until the headlights are turned off.

At the start of production for the 1996 model year, Nissan redesigned the throttle-position sensor and idle/full-throttle switch assembly.

Ford Taurus/Mercury Sable cars with the 3.0-liter, 12-valve Vulcan V-6 engine may develop a leak from the engine rear-main oil seal after fly-wheel replacement.

Where Do We Go From Here?

There is an old Chinese blessing that says, “May you live in interesting times.” As far as the auto-repair and automobile-manufacturing industries are concerned, these are very interesting times. The balance of this year and the next few years will bring about some profound changes in these interdependent industries.

Signal the Return of Weird

Believe it or not, the cause of all of this was a faulty signal switch, or what Ford calls a multi-function switch. Replacing the switch solved all the complaints.

Stepless Ratios in CVTs

Continuously variable transaxles use pulleys and a drive belt as the components needed to provide the vehicle with stepless gear ratios. The basic construction of a pulley is movable and stationary surfaces (see Figure 1). The drive belt Honda uses, constructed of about 280 elements held together by two 12-layer steel loops, is manufactured by Van Doorne Transmissie (VDT) of the Netherlands, with Honda giving it a little tweaking of its own (see Figure 2).

Close Counts Only in Horseshoes and Hand Grenades

Watch out when swapping stator shafts from one pump cover to another on 700-R4/4L60-E transmissions. We have all been there before. You have a unit with a good pump cover and a damaged stator shaft, and in your pile of parts there is a good stator shaft in a damaged pump cover. All you need to do is press the good stator shaft into the good pump cover and you will have what you need to get this car down the road today. Sounds simple, but how often are things that simple in this business?

Solving a Tough Problem With the Tremec T45 Transmission

The T45 five-speed transmission was introduced in the Ford Mustang in the 1996 model year and continued in production through the 2001 models. Tremec Transmissions Corp. in Mexico manufactures this transmission for Ford.

Troubleshooting One-Way Clutches

There was a time when the only fact that you had to know about a one-way clutch was the direction in which the clutch freewheeled. Today you also must be able to troubleshoot some difficult problems related to one-way clutches.

What’s in Your Wallet?

For years now, almost everyone in the automotive-aftermarket repair business has been complaining that we did not have access to the same technical information that the car dealerships have. Well, now you do! But did you think it would be free?