Maybe someone can help me with a couple of codes. I have a VW vanagon with a 2003 WRX motor and stock wrx ecu.

I'm getting some error codes occasionally. One seems to happen when I go over 10,000 feet in altitude. When in the mountains I sometimes get the code:

P0461 Fuel level sensor circuit range/performance problem

I don't know what this code is supposed to indicate. At first I thought this must have something to do with the fact that I'm not sending actual fuel level information to the ecu. I just have a fixed voltage supplied to the ecu so it thinks that the level is always the same. But the dependency on altitude seems strange.

The other code I get occasionally is:

P0230 fuel pump primary circuit malfunction

As I understand it, this is a code that people get when they do a wrx swap into another car and don't use the fuel pump controller from the wrx. In my vanagon I am using the wrx controller and the stock VW pump. I only get the code every few gas tanks worth of driving. I'm wondering if my pump is going bad. I can't seem to correlate the occurance with weather, driving habits, etc.

Any ideas about what I should investigate or change?
Bryan

the P0461 is only going to come about when certain conditions are met for the system to begin some of it's emissions checks. perhaps when you are going over 10,000 feet, that is the only time you drive a steady highway speed for a certain period of time, which is usually what a car needs before it begins evaporative emission checks. while i do know that it requires a certain fuel level (between 15% and 85%) to do it's checks, i am not aware if a varying fuel level is one of the things it checks for as i have not run into one with a stuck float and a code. do you have all of the other proper fuel tank sensors and what have you hooked up? or are you faking those as well? what level are you sending to the ECU?

as for the P0230, my only guess is that the stock VW pump is not meant to be a variable voltage pump and is occasionally sticking or something when the ECU provides it with only half or whatever percent of the voltage than that pump is designed to run on. if the VW pump is meant to be a variable pump, then perhaps it is going bad or some of your wiring is loose/corroded.

disclaimer: my experience is mostly on new fords at the dealership, so some information is subject to brand differences, but codes starting with P0XXX are supposed to be universal OBDII codes, used by all manufacturers with the same meaning.

edit the ecu rom and remove the cel

www.openecu.org

Thanks for the feedback. The evap canistor idea makes sense. I'm faking everything from the tank sensors. (Can't remember the values I'm sending.)

Jaxx, I would love to eliminate the CEL checks for P0461 and a few other things I'm faking-out. I've got a software background, understand serial communication, and own a ScanTool.net elm interface that I use with a PC and a Pocket PC. How much time am I looking at to learn enough about ecu rom editing to make a few changes like that? I've heard its easy to screw up and make the ecu a paper weight that can't be fixed. Is that true?

/Bryan

its really no different than the professional flashing tools

the tactrix cable (necessary) is $75

the big thing for you is to be sure that you kept all the obd-2 ports and flash block ports intact when you did the swap

this might be a better place to start: http://www.scoobypedia.co.uk/index.php/Knowledge/ECU

It is almost too easy. The software has prompts so you don't screw anyhting up. Plus, the 02-03 ecu is one of the most flexible for tuning over the stock settings.

Bryan, My 02 WRX Vanagon conversion gets those identical codes every other tank full also. Watching this thread!

while you are at it you could add another 50 hp ... and tune for your setup ...

i would suggest both of you talk to Dominic
www.getadomtune.com he does remote tuning for a VERY VERY good price (less than a tank of gas)