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.
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
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.
- Throttle closed
- pins 1-2, 1.89 kOhm
- pins 1-5, 2.46 kOhm
- pins 1-6, 3.71 kOhm
- Throttle open
- pin 1-2, 3.92 kOhm
- pin 1-5, 2.46 kOhm
- pin 1-6, 1.75 kOhm
- DC motor, with gearing
- pin 3-4 2.3 Ohm
- pin 3 = (+)
- pin 4 = (-)
- has spring return to closed position.
New opels have a throttle body manufactured together with the plenum, but the actuator motor (stepper motor inside? I doubt CAN):
- Bosch 0205001039 (058?) electric motor
- with AMP 2-828736-2 connector (2nd line empty of the 4 lines, 4x2 total)
Michael Philblad (Tyreso, Sweden) sent Marcell a Volvo Electronic Throttle Module (ETM). Thanx a lot, Michael !!!
[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.
- made in Italy (Magneti Marelli)
- Type is 8644347 (yellow label). Seems to be the replacement part for identical 8644346 (white label) factory item. Don't forget to look for this number as well, when searching for info. Maybe 8644346 is a 3d number for compatible item ([read here]) ?
- any specs ?
- 2x3 pin connector (not the same as the LSU4 WBO2)
- might be able to get the CAN SW spec for the ETM ...
- we can try to decode sniffing CAN (decoding is not necessarily too hard, but it can be)
- hopefully they only apply encryption for the trucks (or they just plan it? I heard they plan it to prevent tweaking), not for normal cars
- [master thesis] - note the picture (we found this on [this page]
- claims that "These throttle bodies are all defective because the contact sensor prongs cut grooves in a plastic contact strip. When the grooves become too big/deep, contact is lost and the engine dies." I guess it's after 150000 km (and heavily depends on mode of operation, the throttle position sensor wears faster in city than on highway) or so, but who knows...
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.
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.
Such items are only for very experienced installers.
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.