WJM Posted November 2, 2005 Share Posted November 2, 2005 Hey guys... i have all of the FSM wiring diagrams and diagnostics etc etc here infront of me...but NONE of them tell me what EACH pin does on the 4-pin TPS on this 2.5 RS. Ive searched...nothing. THere are some links to pics that legacy777 has but they are '404 not found' status... does anyone know what each wire does on the 4 wire TPS? Reason needed...2002/2003 WRX has a 3 wire TPS...RS has 4 wire tps...I am making a hybrid 'adapter harness' and I need to wire in the WRX TPS to the RS harness. any help would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 3, 2005 Share Posted November 3, 2005 Yeah my server is down with a bad motherboard. It may be next week until I can get it back up. The main difference between a 4-wire & a 3-wire is that the 4-wire has an idle switch. The 3-wire calculates this idle start point based on the reading it takes when the car is started up. There is a guy on the legacycentral bbs that has tried to work around this, and I don't know if he was successful or not. There's really no way to just do plain wiring and get the ECU meant for the 4-wire to not have issues with the 3-wire. There needs to be some electronics involved. You may want to search the bbs. Quote Link to comment Share on other sites More sharing options...
WJM Posted November 3, 2005 Author Share Posted November 3, 2005 Well, ECU is WRX for 3 pin..engine is WRX with 3 pin....wiring is all being done thru the stock RS harness...including the engine harness since 80% of the harness plugged right up...the TPS is what I need to rewire...take the 4 pin connector and -1 wire so I can wire on the 3 pin TPS connector. Quote Link to comment Share on other sites More sharing options...
TheBrian Posted November 3, 2005 Share Posted November 3, 2005 Most TPS's I've seen are three pins: 0V, 12V, and signal. You can tell which one is which by taking a multimeter to the car end of the wiring harness. (Assuming you have access to a functional '02/03 WRX). To find the signal pin on the TPS, hook up 12V (or a 9V battery) across the appropriate terminals. The signal pin is the one whose voltage changes as you rotate the TPS's shaft. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 3, 2005 Share Posted November 3, 2005 Well, ECU is WRX for 3 pin..engine is WRX with 3 pin....wiring is all being done thru the stock RS harness...including the engine harness since 80% of the harness plugged right up...the TPS is what I need to rewire...take the 4 pin connector and -1 wire so I can wire on the 3 pin TPS connector. As long as you're using a WRX ECU, you should be golden. You just need to figure out which wires are which, and wire up the WRX TPS connector. Quote Link to comment Share on other sites More sharing options...
WJM Posted November 3, 2005 Author Share Posted November 3, 2005 As long as you're using a WRX ECU, you should be golden. You just need to figure out which wires are which, and wire up the WRX TPS connector. exactly...thats what I need the pinout of the 4pin TPS so i can figure out which ones are which... Quote Link to comment Share on other sites More sharing options...
NoahDL88 Posted November 3, 2005 Share Posted November 3, 2005 now for the obvious stupid question, why not use the WRX TPS? or is this going on a 2.5 engine, which would then ask a second question, would the wrx intake fit on the 2.5? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted November 3, 2005 Share Posted November 3, 2005 exactly...thats what I need the pinout of the 4pin TPS so i can figure out which ones are which... Shoot me an email, I'll email you the scans. Quote Link to comment Share on other sites More sharing options...
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