Was the TDI the first VW Drive-By-Wire Car?

[garciapiano]

Apparently, the first TDI came in the 1989 Audi 100. However, I am not sure if that pump was electronically controlled. Come to think of it, I cannot think of an earlier VW that came with a drive-by-wire accelerator system (there is technically not a "throttle" pedal in a TDI).

Is this correct?

 

[Steve Addy]

Apparently, the first TDI came in the 1989 Audi 100. However, I am not sure if that pump was electronically controlled. Come to think of it, I cannot think of an earlier VW that came with a drive-by-wire accelerator system (there is technically not a "throttle" pedal in a TDI).

Is this correct?

The parts catalogs make no mention of DBW that early, and although the illustrations can be inaccurate I tend to think that 1989 is a not correct.

In fact I went and looked at the list of discontinued TDI engines and according to that list (which came from information in ETKA) the earliest TDI was in fact 1991 when the 2.0L L5 TDI was installed in the Audi 100 08/91. This engine had electronic controls so DBW is likely.

We also know that in the same year a month later the 1Z was installed in the Audi 80 and that engine has electronic control with DBW. The same 1Z was installed in the Golf but not until 1993 sometime.

I think who ever wrote up that Wikipedia listing for TDI with the 1989 date needs to do a little more (but easy nonetheless) research about this.

As for DI though, the first known car with turbo direct injection was the Fiat Croma in 1988, and by 1991 it had VNT variable geometry turbo...talk about early! And even GM was not far off with DBW, which appeared on the 1994 6.5 D & TD engines.

I can't say whether the Croma had electronic controls or DBW, but I doubt it, then again Peugeot was supposed to have Bosch electronic control in 87 on the XD3T but the car never made it to the US so we don't actually know what that looked like. Perhaps since it was a Bosch system there might be pictures online, I think it was called VP17 but I'm not entirely sure.

Steve

 

[oilhammer]

There were some last-gen 3.8L F-body GM cars that were drive-by-wire throttle bodies. That car came out in '93, but I think they used the 60 degree V6 for the first couple years, so I think the 90 degree 3.8L debuted in '95 or so.

I just remember thinking it quite odd that they had the technology, yet it was only used in one [lesser] engine in one [lower production] model.

Of course, there was a period where GM had overhead cams and port injection on some low-end 4 cyl entry level cars, yet the big Cadillacs had pushrods and throttle body injection, so....

Subaru was still using cable controlled throttles up until just a few years ago. Toyota's first electronic throttles happened in '98, on the 4.0L V8s (sold here in the Lexus GS, SC, and LS), but they evidently did not have much faith in them, because they ran a cable out to the side of the throttle body that moved the sensor that was mounted directly on the throttle body.. and as a "failsafe", if floorboarded, could mechanically over ride the electric servo motor and give about 10% throttle opening. Enough to limp you to the side of the road.

I think electronic controlled diesels seem to be quicker to use drive by wire, although I am not really sure why. The act of using an electric stepper motor to move a mechanical diesel fuel control rod/valve/piston isn't really any different than moving a throttle plate, but whatever. Maybe because electronic controlled gasoline engines were already well established by then and they were slow to enact changes due to cost.

 

[Mongler98]

First drive by wire car was back in 88 by BMW in the 7 series . Was called EML
But if you want to get technical, the first drive by wire cars was way back in ye olden day. Like 1909. Jay Leno has a baker electric car that is a drive by wire. So........ maybe there are older but I have no idea.

 

[d24tdi]

I just remember thinking it quite odd that they had the technology, yet it was only used in one [lesser] engine in one [lower production] model.

Although that may seem counterintuitive, in my experience it's fairly common practice in the industry with introduction of new technology that the manufacturer is less than completely confident in. That could be either from a technical perspective or a consumer acceptance perspective (or maybe even a production volume perspective too, I'm speculating there). They get to test the waters a little on a slightly more obscure product before really committing to major mass production for their bread and butter lines. Makes some sense when you look at it from that perspective.

Think the availability of the DSG trans in BEW Beetles starting in '04, while the much higher volume Golf and Jetta on the same platform kept the conventional torque converter 09A. I don't know this for sure, but I have always guessed that is an example of this kind of thinking.

I spent some years working in the corporate emissions compliance engineering division of one of the heavy duty over-the-road vehicle OEMs. When we were preparing to introduce a new piece of emission control or diagnostic technology -- for example a new OBD technique that achieved compliance while eliminating a previously used mid-bed SCR catalyst NOx sensor by determining catalyst efficiency with interpolation from the other existing sensors, to reduce production cost -- the planners would deliberately implement it for the first year or two only in one particular rating (i.e. output level -- as these engines would usually be available in a variety of different ratings, with different cooling system packages to go with them, etc). Usually they would choose a rating that was sold at relatively low rates, avoiding the most popular versions.

This would serve the purpose of getting the technology into the field, but do so in a limited way, so that if it exhibited problems they hadn't found during internal or field testing -- or worse (from their financial perspective) if they wound up forced into an expensive compliance-mandated emissions recall for whatever reason -- the problem and the costs would be contained to a fairly small population. Risk mitigation.

There are quite a few examples of this out there if you look for them. Fun to see them and imagine what the decision process might have been. Sometimes the products themselves reveal the thinking around, or lack of faith in, the idea -- like in that example of the failsafe mechanical override on the Lexus throttle body.

Some early gasoline DBW applications were problematic. The original "ETM" (electronic throttle module) on Volvo 5-cyl engines starting in '99 is a notorious example. My guess is the wide implemention of DBW occurred sooner for diesels because it gave greater advantages for emission control than it does for gas engines, which can still generally achieve it even with the human driver still physically manipulating an actual mechanical component of the engine. DBW removes that connection and can buffer the driver's inputs to avoid the most challenging situations from an emissions perspective, like a sudden large pedal input, etc. Plus of course some diesel injection technologies (e.g. HEUI and common rail) that became increasingly prevalent really don't lend themselves to mechanical control anyway, since unlike a gasoline throttle there's really nothing a cable connected to the driver's foot could operate.

Interesting discussion.

 

[oilhammer]

The DSG was actually in use in a much larger variety of vehicles in Europe in 2004, and they were "halo" cars like the R32 and TTRS. VAG actually had a pretty high opinion of them (still do). They usually introduce the new tech in the high end cars (mostly Audi) and it spills down the line. The big Audi got the TDI first, they got the 5 valve engines first, turbocharging (gas and diesel) first, etc., etc.

There was a GDI engine in the Golf early on, though, that predates any GDIs we got here by at least a half decade. They got PDs several years before we did, too.

 

[Matt-98AHU]

Apparently, the first TDI came in the 1989 Audi 100. However, I am not sure if that pump was electronically controlled. Come to think of it, I cannot think of an earlier VW that came with a drive-by-wire accelerator system (there is technically not a "throttle" pedal in a TDI).

Is this correct?

Old parts catalog I have when selecting "Other" market shows the emergence of the 1T engine code, 2.5 5 cylinder TDI with electronic pump, as showing up for model year 1990. Likely introduced in 1989 but wasn't actually in production until 1990.

Looked up part numbers and illustrations/photos of pistons, which have the direct injection combustion chamber in them, injectors, which are the clamp-in style direct injected setup instead of the threaded in IDI, no pre-chamber in the head, electronic injection pump and, yes, throttle by wire. Sensor on the pedal, no cable going to the pump.

This old copy of ETKA also indicates the engine was only in the Audi 100 for a single calendar year. It's "mounting time" was 01/90 through 12/90. Want to talk about a unicorn, especially at its age. It was rated at 120 hp from the factory.

The Audi 80 had the 1Z 1.9 4 cylinder from 09/91 through 07/95, other models didn't seem to get it until 1995 mostly.

There's a VIN split in 1991 where the early 91 Audi 100s got the 1T engine, the later ones replaced it with the 115 hp AAT and ABP engine codes, still 2.5L displacement. There also is a normally aspirated 2.4L AAS code engine, 82 hp, which is still a mechanical IDI diesel.

Well, this has been a fun fact-finding mission. I had heard of TDIs "being introduced in 1989" before, and that it was the 2.5 5 cylinder, but never had the full facts staring at me in the face or what the engine codes were, outputs, and I assumed and just now confirmed that yes, even those earliest TDIs were all DBW with an electronically controlled pump for fuel quantity and timing advance.

 

[Matt-98AHU]

As for the VW brand itself, the European market saw the 1Z installed by July 1993 in the Vento and Golf. Passat by October 1993.

What also threw me for a loop was seeing "22R" listed as an engine code in the identification list right under 1Z.

Thought to myself "That's a Toyota engine code". Showed as being installed in a model called the "Taro" in 1989 through early 1997.

After some Wikipedia'ing, turns out the Taro is infact a rebranded Toyota Hilux.

Slightly off-topic, but interesting to learn nontheless.

 

[Steve Addy]

It's funny that the 1T is not mentioned in the list of discontinued TDI engines. I did manage to find this on wikipedia, which should be trusted with a grain of salt.

"The Audi 100 also featured a 2.5 L straight-five direct injection turbo-diesel (TDI) model with 120 PS (88 kW) introduced in January 1990 (engine code 1T). This was the first model to wear the TDI label. It had a brief career in the C3, being replaced in December of that year when the C4 arrived."

I referenced that list of discontinued engines when I formulated my response, it's too bad the 1T, which is obviously no longer produced, isn't listed there. even if it only predated the later TDI engines by several months.

Interesting topic indeed.

Steve

 

[Matt-98AHU]

From what I gather, the C3 was replaced by the C4 part way through the 1991 model year. So there are a few 1991 model year C3 100s (aka 5000s here in the U.S.) with the 1T in it, but they were assembled through the end of calendar year 1990 as early 1991 models. Then the C4 100 came out part way through the 1991 model year and the 1T was replaced with the AAT and ABP engines, which are 5 horsepower down compared to the 1T for some reason.

I kinda want one, now. Wagon quattro. 5 cylinders have a neat sound to them.

 

[Matt-98AHU]

I'll also note that the "T-DIESEL" in the "Remarks" column threw me for a loop for a little bit, because other TDI engines are more obviously labeled TDI there, except that very first 1T code engine.

But when I look up parts relating to the 1T, it's all obviously TDI, from the electric pump, to the throttle position sensor mounted on the pedal, to the pistons, the injectors and how they're secured into the head etc.

But the "T-DIESEL" label in the remarks column had me initially digging deeper in the parts program to verify if it was a TDI or an IDI turbo.