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Discussion Starter #1
got stuck on the free-way today truck died . popped efi fuse ... so i swap wiper fuse poped when i cranked it, had a buddy bring me 20 amp fuse pop it when i cranked , didnt wanna pay 200 bucks for the tow so i brideged it with a wire.

can't link to ecm with scanner and no cel when key is on before crankking

help help
 

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Pussay!
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You have a short somewhere on that circuit...search for fsm manuals, there is a post on here with all the wiring diagrams, that'll help you out
 

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Discussion Starter #3 (Edited)
bump bump bump enolia save me ,,, update it only pops efi fuse right after a light brakeing then bam truck shuts off new fuse in runs tell
:shrug: rpm seems to die off dont even know where to start problem only happens right after throttle plate closes so possibly iac crank sensor or electrical nightmare helop i am going to try change the fuel filter my 255 fuel pump might be over working the circuit pray
 

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Mambeau / Admin
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The 20A EFI fuse powers exactly one thing - the ECM. Through the ECM it can also serve as the power source for the electronically-controlled auto transmission (ECT) stuff.

This means anything shorting out 'downstream' of the ECM (which is pretty much everything engine-related) could cause the EFI fuse to blow.

The fuel pump is one of the 'downstream' items. However, I don't know that it's a 'more likely suspect' than anything else.

The fact you cannot link up your OBDII scanner implies the ECM is de-powered or dead. Have you tried connecting the scanner with a good EFI fuse in place? Check your 10A OBD fuse in case that's blown as well.
 

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Discussion Starter #5
problem only happens on braking or deaceterion every time i slow down it pops when a good fuse is in it doe make communacton with the pcm no code to be found i am screwed i am rding a bike 10 miles in 100 degrees weather to work and school

10 $ in fuses later i determined i have a chinses 255 lph fuel pump hmmmmmmm maybe i should swap the stock one it is a a pain job
well,,, i disconnected different iteams to try isloate the circut, after both 02 sensors where disconnected it tripped fuses every time i toched the brake. ,, there is so much chopped wiring on my ecm harness for the piggy backs that i dont even know where to start. :silly::silly::silly::silly::silly::silly::silly::silly::silly::silly::silly::silly:

i don't even think this problem is salvage able
 

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Mambeau / Admin
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Clues, please ...

(1) Manual or automatic?

(2) Do you have cruise control? If so - have you been using it?

(3) Is this a California-spec or Federal-spec 2000 V6?
 

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Mambeau / Admin
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If the EFI fuse always blows when the brakes are engaged, it might be as simple as a short (whatever) in a single ECM connector. The main battery power line (from the EFI fuse) and the brake / stop signal line (from the brake switch) connect to the ECM via the same connector, and their pins are in close proximity (literally right next to each other for a California-spec 5VZ).

I'd suggest disconnecting your brake switch (somewhere around the brake pedal), putting in a new EFI fuse, and seeing if it happens again.

NOTE: Disconnecting the brake switch will disable your brake lights. Don't do this test in traffic.
 

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Discussion Starter #8 (Edited)
dont even know where to start looking tell now
Enola Gaia; thanks for the help very much i am going to take the dash out i think it lies behind there , my piggy backs are tapped into main ecm power a/f sensor , crank, cam, maf, and main ignitor signals,, short to ground in there or my fuel pump is drawing the excessive amp's .. i basicly gott everything that is off the efi fuse flowed in this diagram but i dont know how to isolate indivual circuts,, i dont know how to for say how to elimate the maf as not being the problem and then elimate the a/f sensor and so on

my truck is a 2000 5vz cali equped ,, manuel windows no cruise , 2wd automatic
i tried to disconect the brake light switch and cranked it with a 30 amp fuse ,, ran out of 20 amp s ,,, it blew the fuse before i could even crank it ,,,now it wont even start period , this morning it was just popping fuses when braking or slowing down ...i dont wanna jump the fuse and melt the circut i shall give it another try again in the morning right now both 02 are disconnected so i will plug them in and remove brake light switch and crank it and go from there ,,, another 5 bucks in fuses damm those things are getting expensive :eyecrazy::eyecrazy: i know when it blows the fuse cause the check engine light wont elumanate with k.o.e.o. ''key on engine off''.. i printed a huge wire ing diagram off mitchel and deamand ,,the maf both 02 sensors iac, fuel pump and opening relaying and few more run off off the efi fuse......the main power b+for the ecm is white and red i have to check that wire ,,, its on the the farthest ecm connector to the right ,,, if that is right next to the brake signal i think i have it nailed ,,,,,,,i need the ecm pin break down if you know where to find it Mahloa bra da
 

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Mambeau / Admin
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Here (attached) are the 2000 California spec 5VZ ECM pin layout and the engine control wiring diagram ... :waytogo:
 

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Discussion Starter #10
Sh!t outa luck is there any way to check the PCM
 

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Mambeau / Admin
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PCM? :shrug:

Do you mean the ECM or ... ???
 

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Discussion Starter #12
ecm and pcm and intagrated i think , well any way the thing behind the dash any . is there any way to check if it went bad before i go chasing geese
 

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Mambeau / Admin
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There's not a lot you can do about testing the ECM itself.

One thing you can check is the power supply to it. Here (attached) is the test procedure.
 

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Discussion Starter #14
:drool::runaway:whats a junction box do you know ?

problem has changed to crank no start,, basicly pops the fuse every time i crank the engine ,,, popped a 30 amp fuse so what ever it is is more than 30 amps. strange thing is a jumper wire starts it everytime and runs great ,, i only ran it for 15 secodns dont wanna melt the circut ,,,
 

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:drool::runaway:whats a junction box do you know ?

problem has changed to crank no start,, basicly pops the fuse every time i crank the engine ,,, popped a 30 amp fuse so what ever it is is more than 30 amps. strange thing is a jumper wire starts it everytime and runs great ,, i only ran it for 15 secodns dont wanna melt the circut ,,,
You obviously have a short somewhere, start tracing wires and find it. You said your tie in job for the urd kit was hack, maybe start there? Also check your o2 sensor wiring, I've seen them melt to the exhaust and short out
 

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Mambeau / Admin
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:drool::runaway:whats a junction box do you know ? ,,,
Assuming you're asking in relation to the wiring diagram in the last thing I posted ...

J/B No. 1 = Junction Block No. 1 = The fuse / relay box behind the lower left dash.
 

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Discussion Starter #17
now its a crank no start :puke:
walked outside poped a fuse in made communication with the comp. front 02 reading 3.2 volts on the scanner rear reading 0 volts traced the wires up nothing abnormal back probed the rear 02 sensor with key on egine off 12 volts on both ground and power of the heater curcuit wires did this test with sensor disconnected on the ecm side off connector ,,,, is that right to read 12v on both sides off the circut with the igniton switch in the on postion>>>>>>?????????:shrug::shrug::shrug::shrug::shrug::shrug::shrug::shrug::shrug::shrug::shrug:

cut the power wire to the rear 02 sensor heater at the junction box ,,, no crank no start reconnected the wire crank no start ,,, i guess it;s not the igintion switch thats bad didnt pop the fuse with the igntion switch in the crank postion,, 5vz is not a ecm controled starter it will crank with no power to the ecm maybe my starter went bad i hammered it and it just clicks battery is at 12v's and terminals are clean

,,
 

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Mambeau / Admin
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I believe that's right - there should be a straightforward 12V current flow on the heater part of the circuit with the key in the 'on' position.
 

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Discussion Starter #19 (Edited)
12volts on both heater wires ,,, not sure if the 02 sensor itself is the ground ,or one of those wires is a ground ,,,,, beacuse both heater wires are carrying 12volts , i know there heater cause theere black on the sensor side doesnt matter if the sensor is plugged in or not both heater wires carry 12 volts on ecm side with the key on egine off ,,,i have it down to fuel pump or rear 02 :applause::applause::applause::applause:
 

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problem has changed to crank no start,, basicly pops the fuse every time i crank the engine ,,, ,,
Its easy if it happens consistantly..intermittant issues suck!
Unplug the connector under the drivers seat and crank. If the fuse pops, its not your pump. You'd probably be better off rigging a 20A circuit breaker into that EFI fuse location til you narrow down th problem...cheaper than a fist full of blown fuses.
EFI fuse powers your circuit opening relay,fuelpump and sender,O2 sensors, IAC valve,MAF meter, VSV for EGR, VSV for EVAP, VSV for pressure sensor, ECM, and Point side of the EFI relay. Unplug those components(except for the last two)..crank test..and see if the fuse blows. If yes, you may have a circuit thats shorted. If NO, then it may be one of the components you disconnected. Reconnect one by one and crank test each time til the fuse starts popping again.
If problem becomes intermittant again, wiggle test the harness in suspect area (like where you rigged your piggys) to see if you can duplicate or force the issue. Seriously,It really isn't that difficult to narrow down the problem:shrug:
You might even be able to unplug connector "B" the 16PIN E6 connector from the ECU and run your crank test to see if its one of the wires on that plug..but not 100% sure coz you'll lose your E1 computer ground in the process..but may be worth a shot if the prior tests don't nail down your trouble area
 
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