VEXED, ONLY discussing ETM Failures

[DonWillson]

VEXED is an acronym for Volvo Enthusiasts eXposing Egregious Design.

VEXED means; irritated, troubled, agitated, disturbed or p----ed off.
Egregious means; conspicuously bad, glaring, flagrant.
So we have 'Volvo lovers showing Volvo that their design is criminally defective."

VEXED members are a loosely organized group that have (or did have) love for
Volvo automobiles, not just as 4-wheels and an air conditioner, but as a safe, reliable and well designed piece of machinery.
Our purpose is to force Volvo into a recall action by using all means available to get the word out that these are just not random failures but are the result of poor design of the throttle position feedback potentiometer.

Your experiences, ideas, help and encouragement are welcome. Think of this as a town meeting where there are no dumb questions.

I will start this with some things I am writing for the VEXED web site.

I just found alternate ways to view these threads. It looks like the Hybrid mode is easies to navigate. You can link you reply to the appropriate topic,


Don Willson
[email protected]

[DonWillson]

First let me introduce myself. I am a 73 year old retired metallurgical engineer. For 27 years I managed a chemical, metallurgical, physical test and failure analysis laboratory for Collins Radio/Rockwell International in Richardson, Texas. Our customers within the plant were the industrial engineers that put the designs into production, the component engineers that evaluate transistors, integrated circuits, resistors, capacitors and any device used in our products and the reliability engineers that determine the likelihood for failure of a device and calculate the mean time between failures. We built devices as simple as the circuits in the Volvo ETM to systems as complex as would be found in the back room of Google or Yahoo. In summary, I have the experience and curiosity to determine the failure of this Magneti Marelli built electronic throttle module, though I no longer have the resources to work down at the individual electronic device level. From my experience very few of the failures we examined in my lab were caused by the electronic device, they were caused by improper application (such as overloading a device or improper cooling) or by the mechanical portion of the device ( such as switch contacts, connectors or wipers within variable resistors.) As you can see I have the background and credentials to this type analysis.

Don Willson
[email protected]

950 Southridge Greens Blvd
Unit 21
Fort Collins, Colorado 80525

970 266-9797
You may call from 8:00 AM to 10:00 PM (If I am not up by 8:00 I should be.)

[DonWillson]

See the attachments for the failure analysis of units 1 through 4. Unit 5, though showing heavy grooves does not as yet show a wear through.

This electronic throttle module, made for Volvo by Magneti Marelli, a division of Fiat in Italy, has a part within it that will fail in 30,000 plus miles. While the wear is gradual, the symptoms of rough idle, poor throttle response and surging often precedes a dramatic failure which results in the engine going into a limp-home mode or stalling. The repair, generally not covered by warranty, is to have the ETM replaced which costs are in the range of $800 to $1200.

Of particular concern is, not if, but when and where this failure will occur. It becomes a major safety issue if the Volvo goes into a limp-home mode on a busy Interstate Loop at 5:00 pm on Friday.

Through the Internet dozens of instances of failure are on record from 7 countries plus the United States. A major worry is that the replacement part has the same design deficiency ant it too will fail.
Edit/Delete Message

[DonWillson]

See the attachments for the construction of the ETM.

Within the ETM are two potentiometers that generate an electrical signal related to the angular position of the throttle plate. The plate moves through 86 degrees from full closed to full open. As the throttle moves it turns a wiper riding on a painted resistance element. After a finite number of cycles the wiper wears grooves in the resistance element. Depending on the type of driving, this wear eventually penetrates the element allowing the wiper fingers to ride on the plastic film. When this occurs there is no position feedback signal to the ETM computer. Without this reference the computer 'fails safe'. In this case that is turning off the current to the throttle servo motor. When the servo motor shuts down the throttle goes to a position mechanically defined as the 'limp-home' mode. This is a mechanical stop that sets at a sufficient speed to engage the transmission and yet not so fast that the brakes cannot hold it, about 20 mph.
There is no way to easily replace the potentiometer resistance element. Besides, who would want to accept the liability to reinstall a known defectively designed part.

Don Willson
[email protected]

[DonWillson]

As early as 2000 these failures were beginning to appear. Without a complete failure analysis the diagnosis is a hit or miss affair. Complicating the diagnosis was the intermittent nature of the failure, from intervals of daily, weeks or even thousands of miles. As yet, no one has uncovered any evidence that Volvo gave the dealers and guidance or instructions as the the real cause of the failure, but let them each do an ineffective job of troubleshooting. This of course caused the customer time, money and aggravation, and not a few lost loyalties. This can be summed up in " It is like treating their dealers and customers like mushrooms: keep them in the dark and feed them on that stuff that starts with B and ends with T".

In some cases it seemed that excessive black gunk built up was causing a 'sticky' throttle that responded to cleaning of the throttle bore. The reason this seems to work is that in the early stages the failure is very intermittent and the fact that cleaning is helpful is purely coincendental.

Oxygen sensors were sometimes identified as the culprit.

As the Air Mass Meter is also an input to engine management, changing it sometimes seemed to be the repair, until the next intermittent failure occurred.

One mechanic reported a 'wallowed' out throttle shaft bushing that let unmetered air enter the throttle. Of course replacing the ETM fixed the problem but for the wrong cause. (The throttle shaft rides in two double shielded precision ball bearings so this cause is highly suspicious.)

Of course 'bad' and 'cheap gas' is an unidentified source.

One dealer accuse the owner of lack of periodic maintenance. This was patently false as the owners records showed perfect adherence to the recommended maintenance schedule, with all the service being done by that dealer.

Another, reported by an independent Volvo garage, that I have yet to check out, is oil in the end caps. For this to happen oil would have to enter the end caps around or through the bearings. Since, in non turbo engines the throttle bore is always under negative pressure, it could only happen with turbo engines, that pressurizes the engine intake, including the throttle. Another clue is that is appears to happen on poorly maintained engines where the nipples on the EGR valves were clogged causing oily blowby to enter the intake.

It is very unlikely to be caused by the electronics. The actual electronic components, if they make it past the first 100 hours or operation should literally last forever. As the manager of an electronics failure analysis laboratory we seldom saw electronic failures unless they had been over stressed (plugging a 115 volt bulb in a 230 volt socket) or ill designed. Most failures of electromechanical devices were due to failures of the mechanical (read 'moving') parts. These failures usually show in within the 'burn in" periiod of 24 to 48 hours.

I am sure we will pick up more horror stories at the information gets out.

Don Willson
[email protected]

[DonWillson]

1. Perform failure analysis on as many ETMs as are available.

2. Collect data on failures from:
Owners via Defect Investigation of National Highway Transportation Safety Administration
Internet forums; Brickboard, Swedespeed, VolvoXC, VolvoSpy, VolvoSpeed, Volvo-forums and others.
Postings on The Center for Auto Safety
From 'friendly' garage owners.

3. Contact Volvo Customer Care with the evidence and ask for their response. (this was mailed on March 15th)

Note, on March 31 they mailed their response,http://www.volvoxc.com/forums/editpo...tpost&p=47129#
Mad
" ---Safety is a core value for us and our vehicles are equipped with a "limp home" module. This feature allows the car to be navigated to a safe area or, if the distance is short, to the repair facility.

"In the event a Volvo driver has a problem with this part we support our vehicles with a four year or 50,000 mile warranty. Our network of authorized Volvo Retailers can address all warranty as well as customer pay repairs."

4. Spread the word:
I have a tentative interview with a local network TV station, think 60 minutes.
Send press releases with backup data to auto magazines, USA Today, Consumer Reports and many more yet to be defined.

5. Contact our US Senators and Representatives and ask them to build a fire under NHTSB as there is plenty of evidence there to support our claim that this is a safety issue as the failure mode may leave you as a target on the freeway at 5:00.

Don Willson
[email protected]

[DonWillson]

Nowonmy7thvolvo said that he occasionally felt a fault at 73 mph. However, since the dealer could never find a code, they would not replace the ETM.

Check out http://www.obdii.com/ It confirms what I originally posted below.

There are two categories of DTC's that apply to OBDII. They are listed below with Type A being the more severe.
Type A
1. Emissions related.
2. Requests illumination of the MIL after one failed driving cycle.
3. Stores a freeze frame DTC after one failed driving cycle.

Type B
1. Emissions related.
2. Sets a Pending Trouble Code after one failed driving cycle.
3. Clears a Pending Trouble Code after one successful driving cycle.
4. Turns on the MIL after two consecutive failed driving cycles.
5. Stores a freeze frame after two consecutive failed driving cycles.

My reply:

I would suspect that the program for ‘throwing a code” has an intentional timing imposed to that you do not get a code unless the problem persists. Just like you might not get up every time a baby whimpers but you do respond for sustained crying. This would prevent false alarms.

I checked and all cars sold in the US since 1996 and newer must be equipped with On Board Diagnostics. The EPA has mandated that all manufacturers have to have a certain core set of codes for checking the emission components. However, each manufacturer can have additional codes unique to their cars.

DonWillson
[email protected]

My guru in Texas says,

When a fault is sensed the code is stored in a data bank, and coded as ‘pending’. If the next time the car is started and the same fault occurs the code is stored in the data bank and coded as a ‘fault’. However, if on the next trip, the fault is not encountered the code is erased.

So, you drive to the next county to get a six pack and hit 73 mph, a code is stored as pending. No matter how many 73 mph hicoughs you get it only stores one fault per trip. But your trip home is hindered by construction and you never hit 73, so when you stop the pending code is erased. For the code to be reported by the OBD II. You must have the same fault on two successive ‘starts’.

This may shed light on why some high mileage cars have no problem. They drive 50 miles to work then drive 5 miles to lunch, so the code is never set. But a city driver, that hits the idle, low speed, fault on every trip will get a code thrown often. Does this describe your driving habit; your 73 mph trips are interspersed with under 73 miles per hour trips. Next time try this. If you sense a hesitation pull off in a safe place, turn off the engine and wait a minute or so, then start and drive, hoping to feel the 73 mph hesitation. Now, if my source is correct this should have ‘thrown a code”. My source, also says that it take several restart starts, without a fault, to erase a fault code. Of course the OBD can be reset manually.

Let me know if this works. Does the second instance turn on the ‘check engine light’?

Does this pattern fit others?

[DonWillson]

Of course file a compaint with Volvo
http://www.volvocars.us/_Tier3/ContactUs/
The Assistant Manager of Volvo Customer Care is Susan Campbell

Then NHTSA (National Highway Traffic Safety Administration)
http://www.nhtsa.dot.gov/

The Center for Auto Safety:
http://www.autosafety.org/index.html

These are all places that the individual, not active on the Volovish forums would register a complaint. Be sure to give them enough information that the realize it is an electronic throttle module and it is a safety issue.

Don Willson
[email protected]

[DonWillson]

Hello International Friends,

Up to now VEXED has found postings from Sweden, Scotland, England, Malaysia, Italy, New Zealand and Australia. In the years 1999, 2000 and 2001 there were 517,000 series 70 and 80 Volvos produced and only 250,000 sold in the United States. What is going on with the other quarter million cars?

Is there some other bulletin board that VEXED should be posting on. I presume that since there are some complaints the cars are the same world wide. Or is there a difference in European and Asian cars? Help me out.

In the different countries how do you file complaints? Is there some European Union organization we ought to get into the act?

VEXED need all the help we can get to put our story together. If you are reading this just click on POST REPLY and let us hear from you, or e-mail VEXED directly at the address belos..

Don Willson
[email protected]

[DonWillson]

Hi anyone with a failed ETM,

You can send me the whole part if you only have one. Include the VIN code, mileage, model and year. A brief paragraph about the symptons, failure, where you were, were you in danger and what the dealer claimed was the problem. http://www.volvoxc.com/forums/showpo...41&postcount=1

Copy the VIN code to include when you send a complaint to Volvo, NHTSA and others. See the following URL for complaints
http://www.volvoxc.com/forums/showpo...41&postcount=1

If you are only sending the end caps of if you can get into the dealers box under the bench of bad ETMs, what I need are the end caps. I don't believe there is anything else that I can test. If you only send the end caps do the following:

First: Does the throttle move smoothly? When pushed fully closed can you see light around the edge of the throttle plate, or is cruded up enough to cause the throttle to stick?

Take an electric screwdriver with a T-20 tip, ( a star shaped tip), a pair of wire clippers and a blade screwdriver. Unscrew the end caps, 4 screws each. Wedge the 1/2" x 1" rubber cap off of the left side and clip 2 wires. Then brute force wedge the end caps off The solder joints near the front of the module will break nicely. This does not damage the potentiometer. Send me the complete end caps. These contain the resistance film and the wiper. One mechanic in Denver reported oil in the end cap, especially if it was a turbo. Are the end caps clean and dry inside ( of course there will be some engine dirt on the outside. )

Copy down the information off of the front label, is the label yellow or white. If available, which I doubt, the model and year of the car. Also the date codes off of the module. One is molded into the cable where it connects to the module and one is cast into the casting, it is a circle with a bar across it. Put each endcap pair in a separate baggie with the data. Then the post office now has a 8.5 x 11 x 6" box that is a flat rate priority mail for about $7.85. You should be able to get a dozen or so pair in the box.Also at www.usps.com you can print an address label with or without postage on line. It's slick.

Another question for your mechanic. Has he seen the same problem with the S80 series? Are they the same part number? All information is relavent.

My Address is:
Don Willson
950 Southridge Greens Blvd
Unit 21,
Fort Collins, Colorado 80525
of course the E-mail is: [email protected]