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A look at Toyota's fourth generation of hybrids

Sunday, January 1, 2017 - 09:00
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Toyota Safety Sense
Toyota’s proprietary safety system includes advance collision avoidance technologies such as a pre-collision system with pedestrian detection, lane departure warning with steering assist, automatic high-beam lighting and dynamic radar cruise control that works at a range of speeds and down to a full stop. The TSS-P system on the 2018 Prius is the first among Toyota’s fleet to offer this dynamic set of safety features that will be making their way across the Toyota lineup.

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(Image courtesy of Toyota Media) The fourth generation Toyota Prius
(Image courtesy of Toyota Media) The LED headlamps on the new Toyota Prius

Toyota’s new global architecture seeks to “change how Toyota cars drive” by creating platforms that are “direct and smooth” and “fun to drive,” according to Toyota Media. The global architecture affects all areas of the vehicle and is leading to the production of an array of new powertrain units that began with the introduction of the 2.4L Direct Injection motor on the 2018 Camry. In all, Toyota plans to release 17 versions of nine new engines, 10 versions of four new transmissions and 10 versions of six hybrid systems over the next five model years.

The array of new technologies found on the Prius are immense and some of the new twists on servicing these vehicles are particularly interesting to those who will be repairing these vehicles.

(Image courtesy of Toyota Media) A newly designed rear-wheel drive transmission developed under TNGA

Seven-digit DTCs  
As technology progresses, so has the need for new diagnostic trouble codes. Beginning with the 2016 Toyota Prius and Highlander, Toyota has transitioned to the new format for DTC structure. Gone are the days of alpha-numeric categorization that we have become accustomed to. New DTCs such as a P0A7F began a transition into this new era of DTC structure. Each DTC now features an additional two-digit identifier that helps further narrow a diagnostic process by providing the technician with more information. While this can be initially confusing, it is further proof for the need for good information and appropriate tooling.

Toyota is now using a 7 digit DTC code structure

HV Operation History

Imagine a scenario in which a customer purchases a vehicle and comes to find out that the shifter has been replaced by an Atari-like joystick. This joystick is an entirely new concept, which is not attached to any type of mechanical function and does not provide a resistance such as felt in the “shifter” on a traditional automatic transmission vehicle. Adding to this confusion is the fact that the joystick shift pattern is non-linear and requires pushing an additional button to park the vehicle. This is exactly how the “shifting” is laid out on the Toyota Prius and many other Toyota hybrid vehicles. To put this into context, imagine an elderly relative or another person who lacks tech savvy purchasing this vehicle. Then multiply that by millions of customers and you have the reason for the development of HV Operation history.

Mr. Customer drives his newly purchased Prius into the dealership and complains that his new joystick-operated HEV is not “shifting” properly and does not respond the way that he anticipated. The service advisor creates a work order and the technician is now spending time to determine what the “problem” is with Mr. Customer’s vehicle. You will recall that in any diagnostic routine the first step is to verify the concern. As you may have guessed, this vehicle is scanned for diagnostic trouble codes with none found and the technician has very little information to go on. There is little to no data available to capture this type of complaint, and if there was it would be difficult to find the answer for the problem within the data. The technician returns the clipboard and work order to the advisor with the letters “NPF” for No Problem Found. This is the result of the technician’s work that could have been anywhere between ten minutes and two hours. The result of this expedition is a frustrated customer, technician and service department. If only there was a way to determine what the customer’s problem actually was. Now there is in the form of HV Operation History.

(Image courtesy of Toyota Media) Toyota's new inverter improves on its predecessors
(Image courtesy of Toyota Media) The new independent rear suspension on the Prius was designed with the Toyota New Global Architecture

HV Operation History is a data value set that is available within the hybrid control ECU. This data list can be accessed through the Techstream software by visiting the data list and selecting a custom menu of operation history data. Don’t have a Techstream? These types of repairs make it an attractive option (see below). Within the HV Operation History is a variety of PIDs that make it easier to pinpoint unusual behavior of the hybrid system that may not result in a DTC. Keep in mind that as with DTCs and freeze-frame data, HV Operation History will be lost with the clearing of all DTCs, as well as with the interruption of battery power.

The data in the HV Operation menu is a bit difficult to discern, and as such Toyota corporate has created a Quick Training Guide (QTG) that is available with the purchase of a TIS subscription and can be bought on a 2-day basis if a short-term subscription suits your needs better than a full-year subscription. Toyota’s QTG provides valuable insight into a variety of Toyota vehicle diagnostic scenarios. In particular, the QT014A guide provides some great information on dealing with HV operation data. For more information on accessing Toyota service information see below.

(Image courtesy of Toyota Media) The Prius P610 transaxle features a newly improved, dual shaft electronically controlled transmission assembly.

A complete understanding of the operation of HV Operation History will help you to get to a conclusion of whether a customer’s complaint was perceived or actual.

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