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09 Corolla fuel pump relay location?


kornesque
02-20-2014, 01:43 PM
Hey guys, haven't posted here since I had my 4Runner and all it's quirks. Sadly I had to dump the brute for a Corolla (in granny gold no less) due to my new/improved/extended commute. It's champ tho.

My issue: I recently had the oil changed at one of "those places" and drove it home. A few days later I fired it up for work and she wouldn't catch. The starter sounds like it's turning the plant over fine, but nothing else. I tried to find a fuse or relay for the fuel pump and am having the darndest time with that. Meanwhile I did the old ear near the fuel fill trick to check for fuel pump noise and heard nothing. I'm sure I'm on the right track.

Any clues as to where I might start checking the electrical circuit? Thanks kindly.

Brian R.
02-20-2014, 02:40 PM
The fuse is normally labeled "AM2" and relay is labeled "C/OPN" ("Circuit Opening"). May be under hood or behind dashboard. I believe the fuel pump will only run continuously when the car is cranking or running. The fuel pump will not provide fuel with the key in "ON" position and the engine not running or cranking.

http://www.autoshop101.com/forms/h42.pdf

kornesque
02-20-2014, 03:35 PM
Thank you, found the fuse - I presume that fuse powers the relay? Although I found a small pile of relays behind the small instrument panel on the drivers side (near the door) I'm still unable to ID the C/OPN relay.

I checked the 4 pins on the fuel pump for action while switching the key from off to on positions. One pin has constant 12V to vehicle ground, the others have nothing over 50mV. The only change I observed while switching the key position was the 12V which dropped slightly in the on position. I did a resistance check between vehicle ground and all the pins (cept the hot one) and one went from 80ohm to 120ohm while switching the key. I doubt think this is significant enough to change any electrical condition of the pump, but I could be wrong.

Could anyone provide leads based on this info? I want to do everything possible to handle it myself if it's at my level. Thanks so much.

kornesque
02-20-2014, 07:53 PM
Well the problem is gone. It was suggested to me that if the fuel lines were under pressure that the pump would not run. I was going to start bleeding the supply when it struck me that a non-working pump shouldn't allow the line to remain pressurized after an attempt to start. With the pump unplugged I cranked it over and lo/behold, she fired up and ran for about 10sec. I plugged the pump back in and she's been running great since.

The solution holds no logic for me but neither does most of the stuff on these new rolling computers.

Brian R.
02-21-2014, 02:37 PM
Better to be lucky than smart... :)

kornesque
02-21-2014, 05:21 PM
Better to be lucky than smart... :)


As long as I've got one going for me at any given time. :grinyes:

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