www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2014 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You



Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW MKIV-A4 TDIs (VE and PD)

VW MKIV-A4 TDIs (VE and PD) This is a general discussion about A4/MkIV Jetta (99.5-~2005), Golf(99.5-2006), and New Beetle(98-2006). Both VE and PD engines are covered here.

Reply
 
Thread Tools
Old March 23rd, 2008, 08:02   #16
concours
Veteran Member
 
concours's Avatar
 
Join Date: Jul 2001
Location: Kensington, NH
Default

Quote:
Originally Posted by vzdude
I have to respectfully disagree. I work on numerous brands of vehicles every week, and very few of them have an actual inertia switch. There is absolutely nothing mandated by the federal government on the issue as well. I've been wrong before, but I'd bet my next paycheck on this one! What they DO require is a rollover valve which simply blocks the vent on the tank. Doesn't work real well, and if there is a hole in the tank it's useless. Here is just one example of a vehicle that I can guarantee doesn't have an inertia switch.


OPERATION

All models pass a full 360 degree rollover test without fuel leakage. To accomplish this, fuel and vapor flow controls are required for all fuel tank connections.
Two check (control) valves are mounted into the top of the fuel tank. Refer to Fuel Tank Check Valve for additional information.
An evaporation control system is connected to the fuel tank to reduce emissions of fuel vapors into the atmosphere. When fuel evaporates from the fuel tank, vapors pass through vent hoses or tubes to a charcoal canister where they are temporarily held. When the engine is running, the vapors are drawn into the intake manifold. Certain models are also equipped with a self-diagnosing system using a Leak Detection Pump (LDP) or NVLD Pump, and/or an On-Board Refueling Vapor Recovery (ORVR) system. Refer to Emission Control System for additional information.
That's fine... you won't hurt my feelings. The verbiage you pasted above is an abstract description of a fuel system design, nothing more. Ford was the first domestic OEM to have inertia switches and manual resets in the trunk, before it was commonplace. Think about the thousands of accidents that happen every day, engines are mashed, displaced, fuel lines torn. How many wrecks are there with 15 gallons of gas pumped onto the ground??? NONE... because the switches are there.

Please share with us how you know the following statement you made to be true... we'd like to know.
"There is absolutely nothing mandated by the federal government on the issue as well"

I just checked the four factory service manuals I had here, 2001 Full size GM P/U's and SUV, 2001 Jeep Grand Cherokee, 1998 Taurus, 2000 Impala, all schematics show inertia switch. I remember diagnosing and fixing a faulty inertia switch on my Nephew's '86 Monte Carlo 4.3TBI.

I stand with my initial statement.
__________________
2001.5 Jetta GLS TDI 5-spd, 508,000 miles, 1999 Jetta GL TDI, 222,000 miles, 2000 Jetta GLS TDI, 184,000 miles, 1983 Jetta turbo diesel, 2-dr., 5-spd, A/C(RIP)
1980 Scout Traveller SD-33T
1986 Chev K10 6.2

Last edited by concours; March 23rd, 2008 at 08:05.
concours is offline   Reply With Quote
Old March 23rd, 2008, 08:21   #17
vzdude
Member
 
vzdude's Avatar
 
Join Date: Feb 2008
Location: NW Indiana
TDI(s): 98 Jetta TDI
Default

Quote:
Originally Posted by concours
That's fine... you won't hurt my feelings. The verbiage you pasted above is an abstract description of a fuel system design, nothing more. Ford was the first domestic OEM to have inertia switches and manual resets in the trunk, before it was commonplace. Think about the thousands of accidents that happen every day, engines are mashed, displaced, fuel lines torn. How many wrecks are there with 15 gallons of gas pumped onto the ground??? NONE... because the switches are there.

Please share with us how you know the following statement you made to be true... we'd like to know.
"There is absolutely nothing mandated by the federal government on the issue as well"

I just checked the four factory service manuals I had here, 2001 Full size GM P/U's and SUV, 2001 Jeep Grand Cherokee, 1998 Taurus, 2000 Impala, all schematics show inertia switch. I remember diagnosing and fixing a faulty inertia switch on my Nephew's '86 Monte Carlo 4.3TBI.

I stand with my initial statement.
O.K.....here are some FACTORY wiring diagrams for the 2001 Jeep Grand Cherokee you referenced , just for 1 example. I have access to ALL Chrysler products online, so these are easiest for me to reference. This is only to disprove the blanket statement about ALL vehicles having an inertia switch. The Jeep uses an ASD ( Auto Shut Down) relay that you may have mistaken for an inertia device. The ASD relay uses an input from the PCM to energize the coil and fuel pump, but no actual inertia switch either. IIRC as well, the 01 Chevy pickups use the oil pressure sensor to kick the fuel pump relay off if it loses oil pressure. No actual inertia switch.

http://pics.tdiclub.com/showgallery....00&page=0&sort=
__________________
98 Jetta 1.9L TDI 5 spd. Bone stock.......for now!
vzdude is offline   Reply With Quote
Old March 23rd, 2008, 08:26   #18
compu_85
Gadget Guy
 
compu_85's Avatar
 
Join Date: Sep 2003
Location: Springfield VA
Fuel Economy: 56.3/44/41
Default

On the A2 VWs the fuel pump relay has an RPM input. When the motor stops the relay will shut off, close for just a moment, then shut off again.

-Jason
__________________
Present:
2012 Passat SE TDI DSG. 60,000 miles. Factory Alarm, LED tails, Memory Seat, HIDs 38/48 MPG.
99.5 Jetta "GLX" TDI. 295,000 miles. Half way there!!! Power Memory Seats, HIDs 11mm pump, BV39 Turbo, RCIII 36/47 MPG.
1991 Mercedes 350SDL 230,000 miles, 70,000 on engine. 18/27 MPG.
Past:
1988 Audi 5000S Quattro, 1992 Jetta ECOdiesel, 1991 Jetta ECOdiesel.

Check out the official TDIClub Chat Room!
Quote:
Originally Posted by BRUSSELS BELGIAN View Post
Maybe I should pay MYSELF to do bad work on my car!
compu_85 is online now   Reply With Quote
Old March 23rd, 2008, 08:29   #19
vzdude
Member
 
vzdude's Avatar
 
Join Date: Feb 2008
Location: NW Indiana
TDI(s): 98 Jetta TDI
Default

Here is another example.....lots of reading, but just Ctrl-F and search for inertia.....here's a couple of examples.

Volkswagen of America, Inc. (VW) was concerned with potential reliability problems associated with inertia-activated fuel cut-off switches. VW explained that it was using an engine rotation sensing device for cutting-off fuel flow in its vehicles. VW also stated that additional fuel tank filler valve systems were unnecessary. In addition, VW recommended that we refer to ECE Regulation No. 34 for possible component test requirements, but did not specify particular tests.


Chrysler Corporation (Chrysler) argued that fuel system integrity should be evaluated as a system and expressed its opposition to any initiative to introduce component design or performance requirements into Standard No. 301. Chrysler explained that it used a fuel shut-off device that senses engine rotation for stopping the fuel flow and stated that additional protection had not been shown to be any more effective in reducing fuel related fires. Chrysler stated that it was premature to consider using an electrical power shut-off device for reducing fuel induced fires. Chrysler argued that more research is needed to verify that the proposed mitigation approach will not harm other systems that are critical to occupant protection, during and after the crash event. Chrysler opposed the concept of using fire extinguishers and fire retardant systems for engine compartment fires and stated that the ignition of a vehicle fire does not necessarily occur at a predictable point in time during a vehicle crash. In addition, Chrysler stated that, in some fires, a "second ignition" is encountered that would not be mitigated by these proposed systems.

Volvo Cars of North America, Inc. (Volvo) stated that shutting off fuel flow quickly during and after a crash could help to reduce the risk of engine fires and the spread of fires once one had started. Volvo stated that since a number of methods could be employed to stop the flow of fuel, there should be no requirement mandating certain equipment. Volvo stated that we should give manufacturers the freedom to design their own systems by specifying performance criteria for them to meet. Volvo suggested that we incorporate the plastic fuel tank test requirements of ECE Reg. No. 34 into Standard No. 301.

AND FINALLY...........The proof!.........
Based on the foregoing, we have decided not to pursue rulemaking with respect to fuel system component performance at this time. Our own review of NASS data did not reveal a significant difference in the rate or severity of post crash fire occurrence in vehicles with and vehicles without inertia activated fuel pump shut-off devices. GM crash test data support this conclusion. GM monitored the fuel pump circuitry in all of the crash tests that it conducted for its above-mentioned research. All of the crashes caused electrical circuitry shorting that disabled the fuel pump before the inertia switch could be activated.
__________________
98 Jetta 1.9L TDI 5 spd. Bone stock.......for now!
vzdude is offline   Reply With Quote
Old March 23rd, 2008, 08:29   #20
vzdude
Member
 
vzdude's Avatar
 
Join Date: Feb 2008
Location: NW Indiana
TDI(s): 98 Jetta TDI
Default

It's amazing what you can come up with in ten minutes and Google!
__________________
98 Jetta 1.9L TDI 5 spd. Bone stock.......for now!
vzdude is offline   Reply With Quote
Old March 23rd, 2008, 08:45   #21
concours
Veteran Member
 
concours's Avatar
 
Join Date: Jul 2001
Location: Kensington, NH
Default

Quote:
Originally Posted by vzdude
O.K.....here are some FACTORY wiring diagrams for the 2001 Jeep Grand Cherokee you referenced , just for 1 example. I have access to ALL Chrysler products online, so these are easiest for me to reference. This is only to disprove the blanket statement about ALL vehicles having an inertia switch. The Jeep uses an ASD ( Auto Shut Down) relay that you may have mistaken for an inertia device. The ASD relay uses an input from the PCM to energize the coil and fuel pump, but no actual inertia switch either. IIRC as well, the 01 Chevy pickups use the oil pressure sensor to kick the fuel pump relay off if it loses oil pressure. No actual inertia switch.

http://pics.tdiclub.com/showgallery....0&page=0&sort=
Soooooo.... you feel that all the manufacturers interupting the fuel pump in the event of a crash is just a coincidence? They are all just "good corporate citizens"? Sorry, they must made (in most cases) to do the right thing. I stand by my claim.

When I said "Inertia switch" I refer to some way to shut off the fuel after a frontal impact. Whether the SRS signal is monitored and used, the GM oil pressure switch thing was back in the TBI days, now the ECM turns on the fuel pump relay with an output, the ECM's programmed logic to turn that off may be based on the condition(s) of the signal(s) coming from crank sensor, cam sensor, both, oil pressure, SRS G forces sensed or whatever the resident wizards chose to accomplish the task. Same result.

"Factory" manuals... Alldata? JC I cited the four paper HELM books I had laying around.
__________________
2001.5 Jetta GLS TDI 5-spd, 508,000 miles, 1999 Jetta GL TDI, 222,000 miles, 2000 Jetta GLS TDI, 184,000 miles, 1983 Jetta turbo diesel, 2-dr., 5-spd, A/C(RIP)
1980 Scout Traveller SD-33T
1986 Chev K10 6.2
concours is offline   Reply With Quote
Old March 23rd, 2008, 08:54   #22
vzdude
Member
 
vzdude's Avatar
 
Join Date: Feb 2008
Location: NW Indiana
TDI(s): 98 Jetta TDI
Default

Well......they are not "INERTIA SWITCHES" as in the statement that you claimed. Yes....they do shut off the fuel pump, but by other means than the typical "Ford" style inertia switches. My factory manuals are accessed via Dodge's Dealerconnect website. And yes, I have access to Alldata as well. Everything Alldata has is copied from factory service manuals as well. I just call a spade a spade, when I see it. You know, tomatoe vs. tomato. Again.....nothing personal, just want everyone to be informed. I'm no VW expert, but I'm working on it. I'm an admitted newbie to the TDI world, but have been a Master Certified A.S.E. Tech since 1994 and a Dodge Bronze and Silver Certified Tech since 2000.
__________________
98 Jetta 1.9L TDI 5 spd. Bone stock.......for now!
vzdude is offline   Reply With Quote
Old March 23rd, 2008, 08:58   #23
concours
Veteran Member
 
concours's Avatar
 
Join Date: Jul 2001
Location: Kensington, NH
Default

Quote:
Originally Posted by vzdude
Here is another example.....lots of reading, but just Ctrl-F and search for inertia.....here's a couple of examples.

Volkswagen of America, Inc. (VW) was concerned with potential reliability problems associated with inertia-activated fuel cut-off switches. VW explained that it was using an engine rotation sensing device for cutting-off fuel flow in its vehicles. VW also stated that additional fuel tank filler valve systems were unnecessary. In addition, VW recommended that we refer to ECE Regulation No. 34 for possible component test requirements, but did not specify particular tests.


Chrysler Corporation (Chrysler) argued that fuel system integrity should be evaluated as a system and expressed its opposition to any initiative to introduce component design or performance requirements into Standard No. 301. Chrysler explained that it used a fuel shut-off device that senses engine rotation for stopping the fuel flow and stated that additional protection had not been shown to be any more effective in reducing fuel related fires. Chrysler stated that it was premature to consider using an electrical power shut-off device for reducing fuel induced fires. Chrysler argued that more research is needed to verify that the proposed mitigation approach will not harm other systems that are critical to occupant protection, during and after the crash event. Chrysler opposed the concept of using fire extinguishers and fire retardant systems for engine compartment fires and stated that the ignition of a vehicle fire does not necessarily occur at a predictable point in time during a vehicle crash. In addition, Chrysler stated that, in some fires, a "second ignition" is encountered that would not be mitigated by these proposed systems.

Volvo Cars of North America, Inc. (Volvo) stated that shutting off fuel flow quickly during and after a crash could help to reduce the risk of engine fires and the spread of fires once one had started. Volvo stated that since a number of methods could be employed to stop the flow of fuel, there should be no requirement mandating certain equipment. Volvo stated that we should give manufacturers the freedom to design their own systems by specifying performance criteria for them to meet. Volvo suggested that we incorporate the plastic fuel tank test requirements of ECE Reg. No. 34 into Standard No. 301.

AND FINALLY...........The proof!.........
Based on the foregoing, we have decided not to pursue rulemaking with respect to fuel system component performance at this time. Our own review of NASS data did not reveal a significant difference in the rate or severity of post crash fire occurrence in vehicles with and vehicles without inertia activated fuel pump shut-off devices. GM crash test data support this conclusion. GM monitored the fuel pump circuitry in all of the crash tests that it conducted for its above-mentioned research. All of the crashes caused electrical circuitry shorting that disabled the fuel pump before the inertia switch could be activated.
The last sentence is laughable.... that is the most illogical conclusion that could be drawn. I'd not be so willing to bet not becoming a human BBQ that the right wires were damaged and shorted to save lives.

"All of the crashes caused electrical circuitry shorting that disabled the fuel pump before the inertia switch could be activated."

Sounds like your "proof" is merely a transcript of a hearing...

So you claim there is no law requiring the fuel pump to be shut off in a severe frontal impact??? We all bank our families lives that the wire harness to the engine is going to be damaged and the current limiting devices sense the short circuit and respond as designed? Ludicrous.
__________________
__________________
2001.5 Jetta GLS TDI 5-spd, 508,000 miles, 1999 Jetta GL TDI, 222,000 miles, 2000 Jetta GLS TDI, 184,000 miles, 1983 Jetta turbo diesel, 2-dr., 5-spd, A/C(RIP)
1980 Scout Traveller SD-33T
1986 Chev K10 6.2
concours is offline   Reply With Quote
Old March 23rd, 2008, 09:04   #24
compu_85
Gadget Guy
 
compu_85's Avatar
 
Join Date: Sep 2003
Location: Springfield VA
Fuel Economy: 56.3/44/41
Default

No, he said there is no law requiring an inertia switch for the fuel pump. It can be shut off other ways...

-J
compu_85 is online now   Reply With Quote
Old March 23rd, 2008, 09:26   #25
oilhammer
Certified Volkswagen Nut Vendor
 
oilhammer's Avatar
 
Join Date: Dec 2001
Location: St Louis
Default

Modern GM cars use a similar system as Volkswagen. Ford has gone away from the old 'inertia' switches in many newer models, too. That was kind of '80s technology, anyways.

Essentially, if the car has full CAN, the need for such simplistic mechanical/electrical devices is not needed. The ECUs communicate on a stupid-fast baud rate on the CAN bus, and at the same time the signal is being sent to deploy any airbags and fire any seat belt pretensioners, the signal is also being sent to the rest of the ECUs that would require this information...this all happens much faster than any human could think.

Ford has tapped into Volvo's extensive safety R&D as of late, since Ford owns Volvo. Cars like the Five Hundred and Freestyle (once again a Taurus and Taurus X, respectively) are based on a Volvo platform, and the current Euro Focus, Volvo S/V40, and Mazda 3 are also on a shared platform that was jointly developed with Volvo on Ford of Europe. All of this means the Swedes likely laughed at a mere inertia switch. So, throwback models like the Ranger will still have them for the time being, but the Five Hundred likely does not. Why have an inertia switch when a crash sensor is far more accurate and is already needed for SRS use?

Toyota also links the SRS ECU (via CAN, of course) to any and all high-voltage controllers that the hybrids as well as the electric-steered cars use. Again, to safely and instantaneously isolate any high voltage to the batteries in the event of an accident. If a Prius is in a wreck hard enough to deploy the airbags, the main current relay from the main battery bank will NOT be allowed to power up. And if you interrogate the engine/hybrid ECU, you will see the DTC stored for such.

The complexity of modern cars' CAN and multiplexing systems are far more complex than many realize. At Toyota school we counted 16 different things that happened to the LS430 with Smartkey when you simply walked near the car with the key in your pocket! And you could monitor the CAN bus when this happens and actually watch the graphing of the interchange between all the ECUs, but we had to record it and slow it down so we could even see it....it happens that fast.
__________________
oilhammer
www.cardocautomotive.com
oilhammer is offline   Reply With Quote
Old March 23rd, 2008, 10:49   #26
mrGutWrench
Veteran Member
 
mrGutWrench's Avatar
 
Join Date: Aug 2002
Location: Wallace, NC
Fuel Economy: 63 MPG/56/47 (2nd tank) '02 Sedab
Default

Quote:
Originally Posted by concours
(snip) So you claim there is no law requiring the fuel pump to be shut off in a severe frontal impact??? We all bank our families lives that the wire harness to the engine is going to be damaged and the current limiting devices sense the short circuit and respond as designed? Ludicrous.
__________________
__. Hey, CC. The best rule is "when you're only getting deeper, quit digging"!

__. You said that Federal laws require an inertial switch. Please read/search/whatever:
http://a257.g.akamaitech.net/7/257/2...cfr571.301.htm
and let us know where you find that. (I have a time-saver for you, you won't).

__. The standard says that the vehicle must not leak fuel. It doesn't say anything about fuel pumps or fuel pressure or fuel lines or electrical systems or anything. But your statement about inertial switches is just FLAT OUT WRONG.
__________________
MrG, Wallace NC (2002 Jetta, Totalled by drunk, 11/'06) 130K mi in 4 1/2 years/~57 MPG lifetime; New car, '03 Jetta Wagon, CAT, .681 top gear, 170K mi. in 5 1/2 yr, ~53 MPG.

Last edited by mrGutWrench; March 23rd, 2008 at 10:51.
mrGutWrench is offline   Reply With Quote
Old March 23rd, 2008, 16:57   #27
vzdude
Member
 
vzdude's Avatar
 
Join Date: Feb 2008
Location: NW Indiana
TDI(s): 98 Jetta TDI
Default

Thanks for the support.
__________________
98 Jetta 1.9L TDI 5 spd. Bone stock.......for now!
vzdude is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 17:01.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2014
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2013, All Rights Reserved
Page generated in 0.17041 seconds with 9 queries
[Output: 124.99 Kb. compressed to 106.63 Kb. by saving 18.36 Kb. (14.69%)]