Starting with model year 2005 with the 6F50N family transmissions, Ford introduced solenoid strategies. Since then, they’ve introduced the 6F35N, 6R80 family, and the 6R140 units with solenoid programming needs.
It can be a strange and ominous item to deal with from diagnosis to the final test drive. Any test drive with poor shift quality might have you wondering whether the computer needed to be programmed or not. While there are enough programming updates around to warrant a bulletin search, there’s little information on the impact that the solenoid strategy has on shift quality and unit durability.
About the Solenoid Strategy Number
What prompted the need for a solenoid strategy in the first place? Shift solenoids, torque converter clutch control solenoids, and a pressure control solenoids are manufactured to perform within specific operating parameters. In the past, manufacturers produced and tested solenoids for electrical, mechanical, and hydraulic compliance. If they didn’t meet the test standards, they discarded them.
Of course, from a manufacturer’s standpoint, the fewer solenoids that fail, the less product they waste. And the more solenoids produced per day, the more money they make. There’s always a tradeoff between quantity and quality for solenoid manufacturing to remain cost effective.
With simple on/off solenoids, it was easy to pass the necessary test standards. But with pulse width modulated solenoids, force motors, and PWM solenoids with integral valves, it became more challenging to introduce manufacturing processes that satisfied all the test parameters. It also became much more expensive when a solenoid failed.
When those solenoids were combined in groups, it became more cost effective to measure solenoid flow rates relative to the electrical input and assign them a calibration number. In turn, the manufacturer could assign a computer algorithm to the calibration number to provide satisfactory performance characteristics. This enabled more solenoids to fall in the acceptable range. Fewer solenoids get rejected thanks to computer programming-based compensation.
How Does This Work in the Real World?
Here’s where things get interesting: Several shops are handling solenoid strategy programming differently. Many top shops are playing by Ford’s rules and programming the TCM whenever they change the solenoid group. But other shops are experimenting with plug-and-play methods. Understanding what the manufacturer is attempting to achieve will help you examine these options intelligently and weigh the pros and cons.
Of course, using the manufacturer’s recommended process is the best option for staying out of trouble. Whenever you build a unit with a different solenoid group from the one that came with the vehicle, you could end up with poor shift quality, engagement problems, or torque converter clutch control complaints that you can’t correct because of the mismatch between the software and hardware.
The manufacturer’s recommended procedures involve programming the solenoid strategy into the computer system after you’ve installed the new solenoids. First, you’ll need to know the solenoid strategy associated with the new body or solenoid group (figures 1-4).
If you’re installing a used assembly in 6F35N applications, the solenoid strategy number on the lead frame may be incorrect. If someone replaced the lead frame with one from another assembly, there’ll be no way to identify the solenoid strategy.
Use your scan tool to match the solenoid strategy number for your unit. You can use Mode $9 in the OBD Generic function, but most scan tools will allow you to access this information from the VIN-specific scan mode when you perform a health check scan or enter the transmission or PCM data modes (figure 5).
You’ll also need to purchase a subscription from the Motorcraft web site to enter the solenoid strategy number. And you’ll need a J2534 passthru device (or OEM Ford IDS).
This is where shops and remanufacturers have chosen to seek out possible options. The inconvenience of the additional step of physically programming the TCM usually makes it difficult to project an accurate delivery date for customers. And it leaves remanufacturers at the mercy of the end user who installs the unit.
One option is the RAP (Remote Access Programming) kit. With this device, a shop can offer a diagnosis-to-delivery time. The RAP kit also takes away the anxiety that’s often associated with J2534 programming, especially when technicians have no programming experience.
What Else Works?
So, what happens if we skip this programming stuff and just plug and play? This is where we get into gray areas. When you change the solenoid assembly and not the programming, you run the risk of a mismatch between the computer control and the solenoid response.
Several shops aren’t performing solenoid strategy programming and are receiving what they consider to be acceptable driveability results. I say “acceptable,” because, while they’ve cleared the transmission adapts and driven the vehicle to allow for adaptation, and the shift quality is reasonable, there’s always an underlying question of durability.
Here’s where we in the aftermarket industry must provide an answer by using the old-school method of following up repairs periodically with 30-day, 90-day, and annual maintenance checks. To assess this repair method accurately against the OEM process, you need to bring these vehicles back in and compare them honestly with vehicles repaired using the OEM method.
By observing shift quality, torque converter clutch operation, and transitional pressure management, you can uncover signs of premature failure or shift quality management issues that could relate to not having the correct solenoid strategy in the TCM.
For 6F35N and 6F55N applications
Several shops and remanufacturers are simply using the plug-and-play method. Whether they install a new, reconditioned, or used solenoid assembly, the plug-and-play method appears to work most of the time.
Keep in mind that ATRA doesn’t support this method, but we are looking at all aspects related, as we’ll explore further in this article.
For 6R80 and 6R140 applications
Here’s where logic seems to be taking hold. Several rebuilders are changing the solenoids to the #3 ID band across the board (figure 6). The reasoning is that, no matter what the solenoid strategy happens to be in the TCM, you’ll never have a solenoid strategy mismatch that’s too extreme.
For example, suppose you replaced shift solenoid A with a #3 solenoid. If the TCM/PCM happens to have a strategy requiring a #5 or #1 (the extremes of mismatch), it’ll most likely allow the transmission to shift smoothly after you’ve cleared the adaptive values and performed an adaptive test drive. Turns out those shops are having good results using this method. Unfortunately, without supporting data, ATRA can’t support this process either.
This doesn’t apply to the earlier 6R60/6R80 applications with the TCM in the lead frame. These units have the solenoid group and valve body calibrated as an assembly; much like the 6F applications.
Of course, when making an assessment to determine the source of a transmission control-related fault, it’s extremely important to consider the mileage on the vehicle, based on the repair and the engine-side maintenance that was (or wasn’t) performed.
It’s becoming more important to pay attention to the mass airflow sensor and related engine air inlet components to make sure they’re functioning correctly without restriction. High mileage mass airflow sensors rarely set codes, but they can be the source of TCC and shift quality issues that mask themselves as solenoid strategy or solenoid/valve body related problems.
When performing repairs on these late-model Ford applications, you must be aware of the repair procedures to determine the results of your actions. By accurately tracking units that you repaired using OEM procedures relative to those with plug-and-play, you can provide some useful information for future repair procedures.
Comparing unit durability versus not programming solenoid strategy numbers, tracking repair histories of affected vehicles will offer supporting documentation to either validate or invalidate the need to program solenoid strategies.
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