Technically Speaking

Technically Speaking: VLP-Line Pressure Too High

Monday, April 1, 2019 12:00 AM

A 2014 Dodge Journey 2.4L with a 41TES transmission came in to Electronica & Transmisiones in Buenos Aires Argentina. It had code P0869 set for Line Pressure High. Leonardo Luercho went out with the vehicle using his scan tool to begin his diagnostic approach. While observing the data parameter IDs in his scan tool, he noticed that there was a difference between desired and actual line pressure. Figure 1 is a photo of the graph displayed in his scan tool. The blue, more-active line is actual line pressure provided by the VLP sensor. The black, less-active line is the desired command given to the VLP solenoid by the computer.
Technically Speaking: CVT 7 Troubles

Friday, March 1, 2019 12:00 AM

Wayne Colonna discusses the issues with the CVT7 transmission.

The CVT 7 used in Mitsubishi and Nissan vehicles (Figure 1) is unique in that between the pulley assembly and the differential is a planetary gear set controlled by a reverse brake, a low brake and a high clutch.
Suburu 4AT Phase ll Version ll Control and Valve Body Changes

Friday, February 1, 2019 12:00 AM

Sometime at the beginning of the 2004 model year, Subaru redesigned the 4AT Phase ll Control system that placed the transfer clutch control solenoid into the valve body. The new design valve body (referred to as Version II) contained 3 clutch control solenoids, 2 brake control solenoids, a TCC and pressure control solenoid (Figure 1).
Mazda’s SkyActiv-Drive 6-speed automatic unit: Magnet is Loaded with Metal

Wednesday, January 2, 2019 3:54 PM

The progressive development of Mazda’s “SkyActiv®” engine and transmission has resulted in an engine that should be available in 2019 called the “SkyActiv-X.” The name SkyActiv given to this drivetrain reflects their back-casting developing method.
Technically Speaking: When it is Broken

Saturday, December 1, 2018 12:00 AM

Planetary gear sets and their operation are unappealing for many. Know what is turning and what is holding for each gear can challenge one’s thinking. Particularly so when there are 10 speeds and 3 planetary gear sets involved. I actually enjoy pushing my mind to visualize powerflow and indeed, it can be challenging at times. But it sure does go a long way when trying to isolate a noise problem. It also helps when you have missing gears or no movement. This too helps to know where to look. A perfect example of this is in the Technically Speaking column back in December 2017.
Technically Speaking: Very Odd Issues

Thursday, November 1, 2018 12:00 AM

Wayne Colonna illustrates the odd issues that pop up with valve body bolt lengths with an example of Toyota’s U660.
Techincally Speaking: The P0763 Headache

Monday, October 1, 2018 12:00 AM

A call came in to ATSG’s technical help line concerning a 2009 Kia Borrego with a 3.8L engine using a 5-speed RWD transmission called the A5SR2. This transmission is very similar to the Subaru 5AT transmission, a derivative of Nissan's RE5R05A transmission. Mounted on top of the valve body are the solenoids, a sub-ROM and pressure switch frame assembly (Figure 1).
Technically Speaking: An ECU Dilemma

Friday, August 31, 2018 12:00 AM

A 2009 Toyota Corolla LE with a 1.8L engine and a U341E transmission arrives to a shop with code P2757 Torque Converter Clutch Pressure Control Solenoid Performance (SLU Solenoid) Malfunction stored. The unit was removed and overhauled with a new SLU solenoid and a replacement torque converter. When it was tested, the car seemed to be working well but the Malfunction Indicator Lamp came on after reaching highway speed.
Technically Speaking: A Clever Variable Cylinder Management Fix

Wednesday, August 1, 2018 12:00 AM

The number of vehicles containing VCM exceeds 4 million to date, as far back as 2005 – Odyssey, Pilot, Ridgeline and Accord – and Acura MDX/RDX/TLX that have an I-VTEC engine. This problem affects many more vehicle owners than you could imagine.
Technically Speaking: The Variable Line Pressure Solenoid

Sunday, July 1, 2018 12:00 AM

The 41TES and the 42RLE-VLPS are known to produce a “Line Pressure to High” code P0869 due to defective TCM/PCM’s immediately after a 2-3 shift. When this call comes in on our help line, we ask the tech involved to run some tests so we can be certain that a defective computer is the cause. Being a pattern failure, a repair tech can be as costly as buying a computer that doesn’t fix the problem and makes for a bad day.

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