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InTake/DriveByWireThrottle

This page is about electronically controlled throttles. This technology is getting common

[Video of a Ford Mustang] using VEMS and [Bridge Output Driver] for Electronic Throttle. Most installs are BMW, VAG (VW, Audi, ...), and PSA (Citroen, Peugeot) ... the Mustang uses same technology (double pedal sensors, double TPS sensors for feedback, safety relay, and DC motor actuator).

If I wrote an intro it would be similar to [this autospeed article] (except their English is better and they apparently worked on it more than I would have :-).

This page is an index page, and some words about the actuators. However a complete system is much more than that. Redundant network of sensors, smart software and good understanding of failure modes.

See InTake/DriveByWireThrottle/Sensors

Besides the VAG item there are others too.

(make a separate page if info about a particular part > 8 lines)

Newer VAG throttle-bodies:

VAG DBW Page: InTake/ThrottlePlates/VAGElectronicThrottle

PSA

I heard that PSA's shipping lotsof cars (Peugeot 307 and Citroen C5 comes to mind) with drive-by-wire throttles (for years now). That means they should be available for cheap. Dunno about bus (CAN is likely). No CAN, but just - KISS (keep it simple stupid) - gear motor with position sensor(s).

fex. Electronic throttle body fitted to EW12J4 engines (often found from Peugeot 407, 607, Citroen C5 etc.).

Casting is made by Solex (type 'Solex 1943'), electronic unit (motor and potentiometer(s) are made by Magneti Marelli (type CTS CA.0011607B).

Throttle plate diameter 61 mm, flange polt pattern 60x60 mm.

Connector has 6 pins in one row.

- has spring return to closed position.

Opel, BMW

New opels have a throttle body manufactured together with the plenum, but the actuator motor (stepper motor inside? I doubt CAN):

seems to be available < 200 Euro. Used on Y20XE,Y22XE,Z22XE engines.

Volvo

Michael Philblad (Tyreso, Sweden) sent Marcell a Volvo Electronic Throttle Module (ETM). Thanx a lot, Michael !!!

Volvo_ETM_0001_l.jpg

[another pic] the connector is better seen here. Note that the connector hangs free at the end of a 45cm long cable. It is in no way glued/screwed to the body, maybe the picture is confusing.

Links

CAN-ID-s would be important to know. For initialization, actuation, diagnostics, etc... Notify MembersPage/MarcellGal if you have any info that you don't want to write here for some reason.

Home made

[designing an electronic throttle.]

MembersPage/PetrPodrazsky plans to install one on his engine from DC motor.

Controlling it via MAP reading, an appropriate (TPS, RPM, TPSdot) => MAPtarget function can make wonders. Note that it's not very good if it sticks open, but the revlimit fuelcut will save your engine if you're foot is on the throttle, and overrun fuelresume is very handy when TPS=0.

If the throttle is slow, it's impossible to make a nice response system. 150..200 ms is nice from end2end. Appr. 10A drivers are required for that.

Issues

Such items are only for very experienced installers.

Control algorithm

Very similar to the BoostController: (effective) TPS => MAPtarget, measured MAP => actuation

Michael adds: I've also been thinking a lot about implementing drive by wire throttle for a plug and play STi ECU. Also the Audi S4 could benefit and I have a customer with a Nissan Sentra SpecV turbo that is drive by wire.

The control algorithim used by OEMs is extremely complex. It is not simple enough to request a MAP value and have the throttle achieve it. The throttle tends to lag a little from the input and this makes rev matching very difficult with the dumb systems. Some of the nicer systems STi in particular knows what gear you are in and detects a throttle stab to precisely rev-match a downshift. Give anything from a mild to a hard stab and she rev matches perfectly. The ECU also appears to learn how to rev match through some sort of adaptive control.

Another whole aspect is in the safety arena. The ECU must detect a failed e-throttle and use another means of control (throttle controlled rev limit). It should also detect when the brakes are applied and use that coupled with the vehicle speed to allow braking. The cat's ass would be a variable brake input to allow proper left foot braking but at higher pressures allow the override to slow the car in the event the throttle has failed open.

WhatEverYouDoYouDoItAtYourOwnRisk

See also