So one day I got into my REX and it just wouldn't start, it was cranking but no ignition. Tried boosting it but didn't work so it wasn't the battery. Finally the next day my mecanic told me my stock fuel pump is busted and the module connected to the fuel pump was also finished. I asked him what caused this and all he was able to tell me was that the fuel pump was receiving too much amps, and that lead to fuel pump malfunctioning and short circuiting the module. The module really killed me as it cost me 190$ cdn from Subaru (they had to make a special order), but I saved some money by getting a Walbro fuel pump. Anyway the answer he gave me regarding the causing of all this drama really didn't satisfy me and I think they could've been more to it. Anyone got a clue???

specs that might matter:
2002 WRX
up+dn pipe both catless
catback exhaust
bov 100% venting
AEM cai
boosting at 15psi
hp ground kit

Maybe it is just verbage and grammar you used, or maybe it is the whole transaction you had with your mechanic, but, something seems fishy.

By module, do you mean the fuel pump relay? The ECU controls the relay as it recieves pulses from the crank position sensor. The relay in turn sends power to the pump, letting it do it's thing. It is not very complex.

It kinda seems like you got taken, or at the bare minimum, a problem wasn't solved. Why was the pump recieving too much current? If that in fact was the problem and caused it to die, and it wasn't rectified, it will just happen again.

You are right, your mechanic didn't give you very satisfying information.

Can you hear the fuel pump when you turn the ignition to on?

Yeah Rick Schu, now when I start my car I can hear a very noticeable sound and I suspected that to be the fuel pump. Is that normal? I didn't expect the Walbro pump to sound that much different from the stock pump... It's like a high pitch humming-ish sound. I don't remember my car ever making that sound before installing the new fuel pump. Although at some point it will stop when I start driving, at times it persists. Other times it would go silent and back on again :confused:

...and yes SPECIALEV i meant the relay, it's like a little module box (by Denso). "It short-circuited as a result of the fuel pump mishaps" according to the mecanic. Anyway on Tuesday I'm going back to them to ask them for a more detailed/better explanations...

Maybe it is just verbage and grammar you used, or maybe it is the whole transaction you had with your mechanic, but, something seems fishy.

By module, do you mean the fuel pump relay? The ECU controls the relay as it recieves pulses from the crank position sensor. The relay in turn sends power to the pump, letting it do it's thing. It is not very complex.

It kinda seems like you got taken, or at the bare minimum, a problem wasn't solved. Why was the pump recieving too much current? If that in fact was the problem and caused it to die, and it wasn't rectified, it will just happen again.

You are right, your mechanic didn't give you very satisfying information.


The WRX uses a Fuel Pump Controller which is controlled by the ECU. That's the Denso box his mechanic is talking about. The fuel pump relay on the WRX supplies power to the FPC which then supplies a variable amount of voltage to the pump based on the ECU input.

While it's possible the fuel pump and the FPC both burned out it's more plausible the FPC just shorted out and nothing was wrong with the fuel pump. I would have asked for the pump back and just hooked 12v up to it to see if it was really broken.

You can get a FPC from subaruparts.com for about $90 US which is about $110 CDN I think.