Mitsubishi Montero Sudden Acceleration Accidents [MERGED]

[kagalingan]

Mitsubishi Montero Sport SUA Info Group Public Group | Facebook

Comments on the Horiba Mira Report
by Dr. Ronald Belt
8 January 2017

The Horiba Mira report is defective in the following respects:

1) Its analysis of vehicle functions prior to testing concluded incorrectly that battery voltage compensation is not performed on the fuel injection system. Enclosed is a report by Mitsubishi’s supplier, Denso, showing that battery voltage compensation is performed on the fuel injection timing.

2) It misrepresented a theory of sudden unintended acceleration (SUA) advanced by Dr. Ronald Belt, creating a straw man substitute that could be easily refuted. Enclosed is a paper by Dr. Belt which explains his theory as it applies to diesel engine vehicles like the Montero Sport. Note that it does not mention DMA transfer error or the random corruption of SRAM data as the Horiba Mira report alleges.

3) As a result of 1) and 2), it failed to test a critical engine control function identified by Dr. Belt as a cause of SUA. This control function is the battery voltage compensation of the fuel injector timing, the fuel rail pressure, and the variable geometry turbo control, which use the same battery voltage sample. If this voltage sample gets corrupted by a negative voltage spike, then all three voltage compensation functions cause a higher engine speed. Such negative voltage spikes are produced on the battery supply like by other vehicle functions like the air conditioner, the radiator fans, and the ABS brakes and brake lights.

4) One of the three vehicles tested had an engine that was never involved in SUA. The report identifies these vehicles as vehicle 1, 2, and 3. But it never identifies how these numerical designations apply to the three vehicles described.

5) Some tests were performed on a vehicle while idling in NEUTRAL. This mode has never been reported by drivers as a condition supporting SUA.

6) When standard RFI tests and reduced power supply tests proved negative, and a standard conducted EMI test that did cause unintended acceleration was ruled out because the stimulus with the same magnitude could not be found in the Philippine environment, it was concluded that the only remaining explanation for unintended acceleration in Montero Sports was pedal confusion by vehicle drivers. This conclusion failed to consider Dr. Belt’s theory as an alternative explanation. Consequently, this theory was never tested.

7) The report’s conclusion that SUA is caused by the driver and not by the vehicle rests on the assumption that a vehicle origin of SUA requires simultaneous brake failure to explain the ineffectiveness of the brakes during SUA incidents as reported by many drivers. A driver origin, on the other hand, explains brake ineffectiveness by the driver pressing on the accelerator instead of the brake. But the report does not consider that brake ineffectiveness can occur during vehicle-originated SUA as a result of the higher torque produced by the engine, making it more difficult for the driver to apply the brake pedal force required to stop the vehicle. Also, it does not consider the driver’s reaction time to apply the brakes in time to forestall a crash. See the enclosed document that explains how brake pedal force and driver reaction time are important considerations for brake effectiveness, and that the brakes do not always overcome the engine torque if the driver cannot apply the brake pedal force required when the engine is running at maximum RPM.

8) The report’s conclusion that pedal confusion is the cause of unintended acceleration in Montero Sports fails to explain Mitsubishi’s own statistics showing that the SUA incident rate is higher in vehicles with variable geometry turbochargers (VGT). Dr. Belt’s theory can explain these statistics by the fact that VGT turbos use voltage compensation.

9) The report’s conclusion that the Montero Sport is more susceptible to pedal misapplication than other vehicles because of its lateral pedal positioning is inconsistent with other vehicles having similar lateral pedal positions while not having higher SUA incident rates.

[kagalingan]

Continuation

A copy of the Horiba Mira report annotated with Dr. Belt’s comments on these topics and other issues is provided with this critique.
One may ask how the Horiba Mira report could contain so many deficiencies when Horiba Mira is considered to be a world-renowned RFI/EMI testing company. The answer is that Horiba Mira is an expert in RFI/EMI testing, but is not an expert in the design of automobile engine control systems. And to test automobile engine control systems thoroughly, one must know how they are designed. Testing an automobile engine control system requires testing a specific system function. If a function is unknown, it cannot be tested. If Mitsubishi does not explain to Horiba Mira some of the important details of their engine control system design, then the only way for Horiba Mira to know what functions to test is to apply their own imperfect knowledge of the system design. Specifically, if Mitsubishi does not explain to Horiba Mire that battery voltage compensation is performed in the control system, and when and where the battery voltage is being sampled for this function, then Horiba Mira cannot test this important control function. In this case they can only test the obvious functions that they know about. This is what was done by Horiba Mira in creating their test plan and in analyzing their test results.

It is clear from reading the report that Horiba Mira had little assistance from Mitsubishi in creating their vehicle test plan:

1) The report states incorrectly that battery voltage compensation is not performed on the fuel injection system. This contradicts Mitsubishi’s own service documentation on the common rail fuel injection system and the documentation of its supplier, Denso. Mitsubishi could have corrected this mistake by Horiba Mira, but they did not.

2) The report confuses the operation of the idle control system with the operation of the torque control system. It does not state that the idle control system is active only in PARK and NEUTRAL and uses a closed-loop controller that can increase or decrease the idle speed in response to disturbances in voltage and engine load. In DRIVE and REVERSE, on the other hand, the torque control system uses an open-loop controller that can only issue set-points for motor torque. An open-loop controller cannot decrease engine speed in response disturbances in voltage and engine load, but can only increase the engine speed. This knowledge explains why the engine speed never rises while in PARK or NEUTRAL during an SUA incident, which would alert a driver that something is about to happen. Engine speed only rises when the transmission is shifted out of PARK or NEUTRAL and into DRIVE or REVERSE, causing the driver to be surprised by the instant engine noise and torque. This knowledge means that any tests performed while idling in PARK or NEUTRAL are meaningless because they cannot produce SUA. Mitsubishi could have explained this to Horiba Mira, but they did not.

3) Mitsubishi provided three vehicles to Horiba Mira for the test. But one of the vehicles had an engine (the 4D45) that was never involved in any of the 206 or more SUA incidents reported in the Philippines (90% of which used the 4D56 engine and the remaining 10% used the 4D41 engine). Horiba Mira apparently used the vehicle with the 4D45 engine in many of their tests. Mitsubishi could have pointed this out to Horiba Mira before the tests, but apparently did not.

4) The report misrepresents a theory of SUA advanced by Dr. Ronald Belt by stating that his theory involves a DMA transfer error or the random corruption of RAM data. It does not correctly state that his theory involves the sampling of the battery voltage for use by a voltage compensation function in the fuel injector timing, the fuel rail pressure, and the variable geometry turbo control. This compensation function normally increases the three actuator outputs when a low battery voltage is sensed, returning the actuator outputs to the values experienced under normal battery voltage conditions. This prevents the three functions from changing with low battery voltage. However, when a negative voltage spike occurs while the battery voltage is being sensed, compensation is applied to the normal value of the actuator output, causing a higher actuator output than normal. This is the origin of unintended acceleration. Mitsubishi could have corrected this misunderstanding by Horiba Mira of Dr. Belt’s theory because his theory was explained to Mitsubishi by Mr. Nieto during previous discussions of third-party testing sponsored by the Philippine government. These discussions even addressed which circuit node to test and how the test must be performed precisely at the time when the battery voltage sample was being taken. But apparently Mitsubishi did not explain this information about Dr. Belt’s theory to Horiba Mira. Instead, Horiba Mira merely consulted one of Dr. Belt’s earliest papers from 2012 found at Dr. Ronald A. Belt’s Sudden Acceleration Papers – Center for Autosafety and did not look at any of his most recent papers which explained his theory more clearly. The other possibility is that Mitsubishi deliberately misled Horiba Mira about Dr. Belt’s theory, but this possibility has been discounted. In either case, Mitsubishi did not help Horiba Mira to correct their misunderstanding of Dr. Belt’s theory. This failure led to the exclusion of Dr. Belt’s theory in Horiba Mira’s analysis and test plan.

5) In the report’s discussion of the results of bulk current injection on the APS-to-ECU harness, Horiba Mira mentions that a 500 Hz modulation frequency causes an increase in the main APS sensor signal that causes an increase in engine speed with a period of 500 Hz. Horiba Mira theorized that this might be due to RF resonances. Mitsubishi could have explained that this increase in the main APS sensor signal might have been associated with the A/D sampling time of the APS signal, which is the same as the loop rate of the torque set-points to the fuel injector PID loop, and which also may have a 500 Hz period. But apparently they did not, leaving Horiba Mira in the dark.

Not only does it seem that Mitsubishi did not help Horiba Mira with an understanding of their engine control system design, but Mitsubishi also seems to have requested that Horiba Mira modify the contents of their original test report to emphasize the conclusion that the driver was the cause of the sudden acceleration incidents as a result of their negative test results and the lack of any alternative theories to test. This change of emphasis was in lieu of Horiba Mira’s original draft report which recommended only that further tests should be conducted to determine the cause of SUA. Mitsubishi then made the modified Horiba Mira report part of a larger public relations effort to blame sudden acceleration on driver pedal confusion, even before the final report was issued, by making world-wide press releases and an advertising campaign in the Philippines which put information on Philippine TV and in the Philippine press. Before undertaking the third party test, Mitsubishi could have consulted with Dr. Belt and Dr. Anthony, who would have been willing to explain their theories to Mitsubishi in detail and help them with a test plan. But Mitsubishi never did this. After the test, Mitsubishi could have provided the report to Dr. Belt and Dr. Anthony to get their opinions before releasing the results. But Mitsubishi never did this. It appears that Mitsubishi is more interested in stimulating new sales of Montero Sports than in finding the true cause of sudden acceleration. This makes the Horiba Mira report less of a third party test and more of a one-sided Mitsubishi advertising campaign to increase sales for the Montero Sport.

R. Belt
8 January 2017

References:

DR RONALD BELT-Comments on Horiba Mira Report.pdf
Dropbox - 4xx

Mitsubishi Service manual Showing voltage compensation of injectors and spark.pdf
Dropbox - 4xx

Denso common rail service manual for the 4D56 shows voltage correction p1-33 BATT voltage monitor p1-45.pdf
Dropbox - 4xx

Brake Effectiveness During SUA.pdf
Dropbox - 4xx

Some Facts About Sudden Acceleration in Mitsubishi Montero Sport Vehicles -Revised.pdf
https://www.dropbox.com/…/Some%20Fac...%20Sudden%20A…

Sudden Acceleration in Vehicles with Common Rail Diesel Engines.pdf
https://www.dropbox.com/…/Sudden%20A...n%20in%20Vehi…

[jut703]

I was just thinking, bakit nung issue yung SUA sa news, sobrang daming nagcocomplain na nagka-SUA daw sila?

Ngayon, wala nang nagkaka-SUA. Ano yun, lahat ng Montero na nasa daan biglang "naayos" mag-isa?

Nasan na yung mga staunch defenders that SUA exists?

Sent from my SM-N9208 using Tapatalk

[cast_no_shadow]

^

Ask kabayan and Dominic Almelor bro sila yung mahilig sa SUA hahaha


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[monty_GTV]

I was just thinking, bakit nung issue yung SUA sa news, sobrang daming nagcocomplain na nagka-SUA daw sila?

Ngayon, wala nang nagkaka-SUA. Ano yun, lahat ng Montero na nasa daan biglang "naayos" mag-isa?

Nasan na yung mga staunch defenders that SUA exists?

Sent from my SM-N9208 using Tapatalk

you will hear from them when mitsu start to bring the next iteration in the market...

[dr. d]

I was just thinking, bakit nung issue yung SUA sa news, sobrang daming nagcocomplain na nagka-SUA daw sila?

Ngayon, wala nang nagkaka-SUA. Ano yun, lahat ng Montero na nasa daan biglang "naayos" mag-isa?

Nasan na yung mga staunch defenders that SUA exists?

Sent from my SM-N9208 using Tapatalk

popular or not.
correct of doctored.
the horiba report does give some sort of credence to the suggestion that the driver's foot made a mistake.
perhaps some would-be complainants gave it some thought, and... decided on the silent approach...

[RedLabel46]

Hindi nman din pwedeng start engine wth automatic transmission unless it is in park position, so yung SUA will start once the lever is shifted to Drive position.

[minicarph]

Nasan na yung mga staunch defenders that SUA exists?

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Baka nag SUwA na


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[kisshmet]

Hindi nman din pwedeng start engine wth automatic transmission unless it is in park position, so yung SUA will start once the lever is shifted to Drive position.

From P it will pass R first before it reach D. If the driver is not stepping on the brake while shifting gear from P to D then SUA will happen.

In that scenario who is at fault?

SUA claim is a blackmail attempt to fleece money from car manufacturers. Other manufacturers give in to this blackmail modus while others dont

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[mokong22]

From P it will pass R first before it reach D. If the driver is not stepping on the brake while shifting gear from P to D then SUA will happen.

In that scenario who is at fault?



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sa toyota sir hindi mo ma shift from P to R to D without stepping on the brake. Ewan ko lang sa montero.


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