Diagnosing AS68RC intermittent pressure switch/linear solenoid performance codes
Intermittent pressure switch codes on vehicles with the Aisin Seiki AS68RC transmission have been very difficult to nail down to one specific cause. The two most common pressure switch codes for this transmission are P0746 clutch pressure control solenoid A or linear solenoid A performance or “Stuck Off,” which also includes pressure switch 1 mechanical

Chrysler ZF8 generations 1 and 2 identification guide
In 2019, some Chrysler/Ram/Jeep applications that utilize the ZF8HP transmission moved to a second-generation unit with a new designation and numerous changes for better performance and durability. Gen. 1 units are classified as 8HP45, 8HP70 and 8HP90; while Gen. 2 are classified as 8HP50, 8HP75 and 8HP95. Internally, the Gen. 2 transmission had numerous hard

GM 6L series no-movement conditions: Analysis and repair tips
I am certain that many have experienced a no-movement forward, no-reverse or abnormal pressure condition with a GM 6L series transmission, especially since they are one of the most popular unit families in shops today. So, let’s examine some conditions and causes along with a few diagnostic tips for troubleshooting. We’ll go through a few

Critical wear areas and vacuum test locations: GM 10L and Ford 10R series
Sonnax has provided the following guide on critical wear areas and vacuum test locations for the GM 10L series and the Ford 10R series. Technicans working on these models should find the following four pages helpful. Read more columns from the TASC Force Tips series here.

Diagnosing Chrysler transmission max line pressure and P0933, P0869, P1745 codes
This article applies to Chrysler RFE, RLE and TES transmissions that utilize pressure control solenoids (PCS) for line pressure control. The subject is a rather common electrical fault that may occur on the PCS line pressure solenoid circuit, which results in max line pressure. Diagnosis and correction of a max line pressure condition may become

How to fix GM 8L45/8L90 no-move and no-pressure conditions
By now you may have heard of, or even experienced, a GM 8L45 or 8L90 transmission with a no-move or no-pressure condition. Conditions of no movement or no pressure after repair have plagued this unit since its inception. Here’s what you can do about them. Condition 1: No movement after fast learn or programming If

Stop/start accumulators: What you don’t know can hurt you
It’s no secret that the auto industry is making big moves these days, but while a lot is new, one thing that never changes is that the men and women servicing vehicles need to be learning almost constantly in order to do their jobs safely and effectively. Everybody knows not to touch hot exhaust parts,

How to get started with OE ECU reprogramming
The conversation goes like this: I have been paying mobile programmers or remote access programmers (RAPs) far too long. I believe I can save money and time by doing this myself. What type of equipment is needed and what is the cost to get up and running? Let’s find out! In a nutshell, four basic

Troubleshooting Ford 6R80, 6R140 2-3 shift quality issues
We are all too familiar by now with the numerous band numbers on Ford 6R80 and 6R140 transmissions. We know that — unless you are programming in a new calibration code — it is best to replace a solenoid with the exact same band number as what was taken out of that position on the

Ford 6R80 & 6R140: Troubleshooting timing-related shift issues
As the old saying goes: “timing is truly everything.” Or is it? Either way, we know for sure that this is extremely true in the world of transmissions. Timing problems with clutch apply or with combined clutch apply and clutch release can create all kinds of complaints from flared shifts to harsh shifts to a

Ford 6R140: Identifying unique torque converter features and avoiding application pitfalls
The Ford 6R140 was introduced in 2010 (for 2011 model year trucks) as a six-speed used in Super Duty gas- and diesel-powered applications. Today, these units are in high-value, hard-working trucks at the peak of the repair cycle. Aftermarket programming (especially with the diesel variants) is pulling additional power from the engines, putting further loads

Ford 6R140: Repairing the elusive intermittent neutral condition
The 6R140 has been in large Ford trucks since 2011 and is now considered a common unit in most shops. Our discussion today concerns the elusive intermittent neutral condition. At one particular time, this complaint was so common at one particular California utility company with a fleet of trucks that there seemed to be no
