Dear Spook,

They are electrically the same too. This is apparent by looking at 940 1994 wiring diagrams for both systems. So why does Bosch recommends TPS replacement using their own part whereas Rex-Regina using VDO part? Well they're from different systems to begin with but both coming to a common engine. I think if you substitute the VDO part with Bosch TPS you'll be relying on the inherent manufacturing tolerances in the Bosch part to work with Rex-Regina ECU. Practically I think it could be done but with few trial and error adjustments ie repeatedly adjusted until engine idle to post idle transition goes on smoothly.

Regards,
Amarin.

They are functionally equivalent and mount to the same throttle bodies and throttle shafts. To the best of my recollection the electrical connectors are also the same, so as long as that's true I see no reason why they won't interchange.

Do note, however, the Volvo TPS adjustment procedures are slightly different. I'll quote from my old notes:

"Adjusting the TPS. It should trip just as the throttle moves away from its stop so that the ECU knows when it’s no longer supposed to be controlling idle –you’ll hear a click and a click again on the return. You don’t want the TPS click adjusted right on the hairy edge, it needs a bit of tolerance. For optimal adjustment as determined by Volvo, proceed as follows. Start with the switch rotated clockwise away from the stop position. For a Bosch switch, hold the throttle plate closed, turn the switch counter-clockwise until it clicks then continue to the end of travel and lock in place. For a VDO switch, insert a .010" feeler gauge at the idle stop screw (if you don't have a suitable feeler gauge substitute two strips of medium heavy bond 24 lb. computer paper), turn the switch slowly counter-clockwise until the click is heard then lock in place."
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now