#CTSPedal

When it comes to mountains of data like the NHTSA vehicle complaint data base, one man’s junk is another man’s treasure(trove). Yes, there are limitations. But the remarkable degree of similarity of the UA rate between most badge engineered cars, and GM’s consistently low UA ratings speak of statistical relevance to some of us. One of those is David Lapidus, (TTAC handle: David42), whose data diving and Excel skills vastly overshadow mine.

In the last data dive, I used numbers from Edmunds to come up with a UA complaint rate for 117 cars from MY 2005-2010, excluding the flurry of complaints filed with NHTSA after the Toyota mat recall 0f 9/29/09. But those are cumulative, over the five years. David has taken it to the next level, to the individual model year. We may come back to the whole list another time, but initially we decided to focus on the Toyota Camry, since its large volume of sales and UA complaints would inherently increase the statistical accuracy of the numbers. And although this data dive may not solve the UA puzzle, it does raise serious questions about the most recent recalls and the Congressional barbecue of Toyota.

In the TTAC Pedal Series “Toyota Gas Pedal Fix Simulated: Friction Reduced, But By Too Much”, I anticipated that the crude shim fix for the recalled CTS “sticky pedals” would result in an uncomfortable pedal feel at the least and quite possibly unsafe characteristics at worst. A quick refresher: a carefully controlled degree of friction (hysteresis) is essential in an e-pedal, otherwise smooth changes and maintaining steady states in throttle position become difficult if not impossible. I wrote: “Undoubtedly, Toyota’s intended degree of friction will be compromised by this fix, to one degree or another. And drivers may find the fix unpleasant or uncomfortable, also to some degree or another. Clearly, this fix is a band aid to fix the intrinsic limitations of this design.”

I’ve been counting the days until someone complained about the results of the pedal fix. Yesterday it came, from TTAC reader JAQUEBAUER:

My daughter took her 2009 Camry in to the dealer today for the Gas Pedal recall, and were very surprised and disjointedness with the “fix” that Toyota has chosen for this problem. We picked the car up, getting the keys and a copy of the repair order from the cashier. We were not told about any precautions to take or be aware of changes in the operation of the car. The Repair order indicated that the cars computer was reprogrammed, and some work was done on the gas pedal. I asked her to test drive the car in the dealers parking lot before she went home, to check for any problems.

There were 2 issues she found unacceptable, that I want to talk about here.

Update: a portal to all of TTAC’s articles on the subject of Toyota gas pedals is here:

Toyota uses two different electronic gas pedal designs in its cars. The version built by CTS (lower) is the subject of a massive recall, and the 2.3 million units in affected Toyota cars are to be “fixed” by the insertion of a steel shim. This CTS design is also being modified for new Toyota production, currently suspended. To our knowledge, Toyotas built with the other design (by Denso, upper) are not subject to any recalls or NHTSA investigations,. We have spent the last two days tearing down both units, and familiarized ourselves with their designs, reviewed Toyota’s “shim fix”, and replicated the fix ourselves. Toyota’s planned fix will undoubtedly reduce the likelihood of sticky pedals in the short term, but after examining both units, we are convinced that the CTS unit is intrinsically a flawed design, and poses safety risks in the long term, even with the fix. The only right action for Toyota is to acknowledge the long history of problems with the CTS-type unit, and replace them all with the superior Denso or another pedal unit that lacks the intrinsic flaws of the CTS design.

Update: a portal to all of TTAC’s articles on the subject of Toyota gas pedals is here:

We’ve taken it apart, explained Toyota’s intended fix, and now we’ve replicated the “fix” to see what effect it has. It works, but does it work too well?

Update: To see all of TTAC’s related articles on the subject of Toyota gas pedals, go here:

In yesterday’s post , we offered a bounty for anyone to open up both the CTS (bottom) and Denso (top) Toyota gas pedal assemblies. No one took us up, and no one anywhere else has done it, so we took it upon ourselves . Here they are, both e-pedal assemblies taken apart and examined, in our quest to understand if and what the significant differences are, and how Toyota’s possible “shim” fix would work. On initial observation, it appears that the CTS may be perceived as being the more solidly engineered/built unit, in that the pedal pivots on a traditional and solid steel axle whose bearings are brass or bronze sleeves. The Denso’s whole pivot and bearing surfaces are relatively flimsy-feeling plastic. But that can be deceptive, and we’re not qualified to judge properly if it is indeed inferior or superior. So the question that goes beyond the analysis of these e-pedals is this: are these units really the full source of the problem, or are they scape goats for an electronics and/or software glitch? Pictures and tear down examination and analysis follows:

Update #2: It’s clear to me now that the CTS unit I took apart already had the side cover plates (sheet metal) removed before I examined it. One can see where they fit, and are obviously intended to protect the exposed axle pivot and bushing seen above and below:

(Update #3: Also see our follow-up stories on Toyota’s fix and our replication of the fix and its results)