Hmm, I just tried this tonight, resistor in the grey/green wire at pin 2, and a resistor in the yellow/blue from pin 7. Car barely started, didn't even get to try and pull out of the driveway before it stalled out on me. Do you know what you've done wrong yet?Doc_Oc said:
Do you have the resistor in-line with the actual sensor? If you you are merely shifting the "reading" the ECU sees and it should climb when you are on the throttle and drop when not...the intercooler is only so efficient at cooling the air off of the turbo...however it SHOULD read lower than actual based on the amount of resistance you've added.
My car is a 2003 alh wagon 5-speed. I used a 2.2K resistor on fuel temp sensor pin 7- yellow/blue stripe. The other wire Kerma suggested for fuel temp was pin 4, so using 2 might have been your problem. My car idled fine with a resistor in IAT pin 1- brown/blue stripe but threw a cel so I removed the IAT resistor before driving. IIRC, the IAT was only done because Kerma's engine ran rough without both done. Mine runs fine with FTS only. Greenkeeper with the older Passat has his rigged up differently with good results and 18K, different engine though. Page 1 of this thread gives more details on pins and wires. Please post your results, good luck!mchapek said:
Grrrrrrr.....
That's the oneHoneydew said:
I find it odd that it won;t go away when I flip the switch that bypasses the resistor. I did just cut some zipties/electrical tape and move things around and the CEL went away, then it came back and now its gone LOL It doesn't seem to matter if the resistor is bypassed or not, but I know the resistor is working by the air temp readings in Vag-Com.
OK, so let me get this straight: both you and JackBomBay both have 03 ALH's (like mine).... and you currently have a 2.2K resistor in series on the yellow/blue wire (pin #7) connector coming off the fuel pump. Thats the one I had my resistor in until last night...just took it out...as I had noticably worse mileage (around 5mpg), AND my Incoming AIR temp was fluctuating on my scangauge II as I climbed hills (taken from the OBD port) as I drive. I had thought wire 7 was the IAT, not the Fuel temp. So you think (know?) pin 7 is fuel?? (or was that Kerma...dang I am still so confused after reading thru all these threads on this again)...do you have a resistor on pin 4? What IS pin 4...IAT or fuel? Sorry to be so anal on this...but I"ve cut and soldered/ unsoldered 3 wires now...and would LOVE to get it right and GET a tiny bit more mileage AND have the car run good with NO cel's thrown!Honeydew said:
This matched what I observed on my car. Choose one of the wires listed above per sensor for the resistor. Leave the other wire alone. Choice is yours. Yes, both Jack and I used the same wires and resistors (2.2K): fts y/bl and iat br/bl. I chose pin 7 for the FTS because it was easier to spot and pin 1 for the IAT for no particular reason. You only have to put a resistor on one wire for each sensor and must choose which. Currently, I am running only one resistor total, a 2.2K installed on the FTS pin 7 wire, yellow/blue stripe. I removed the resistor from IAT pin 1 right away because of a CEL. Aside from all that, pin 7 must be FTS because there aren't 7 pins on the IAT harness, IIRC. Mine seems to be working, so if you want to duplicate that just use one 2.2K resistor total, installed on the FTS yellow/blue stripe wire.KERMA said:
Before the resistor mod your IAT didn't fluctuate?mchapek said:
That is an interesting theory, the general consensus on this thread and this one is that the ecu retards timing as FTS readings increase to reduce NOx for emissions A change in the actual injected fuel quantity certainly would help explain things. I am too lazy to test this but would be interested to see the findings of others. If this mod is shown to skew scan gauge mpg readings that would be good info for many members as well. I am not yet convinced of this because calculations at my last fill-up corresponded to scan gauge.Rub87 said:
I've been putting this off too long. Fuel mileage in July and August always sucks for me, and this first tank in the month of July is going to be terrible.... my guess is 35-36 mpg, down from 40-42 the last couple months. Hot Hot Hot weather, heavy holiday traffic, and new tires are all conspiring against me. So maybe a trip to RS or Fry's this evening...mchapek said:
And to put a 2.2k ohm resistor in series (inline) with ONE of the wires for each sensor. But people are getting CEL codes if they choose the IAT pin 1 (brown/blue) wire. And non-starts when using pin 4 (brown/blue) on the FTS.
