Lexus Troubleshooting Questions? Ask a Lexus Expert
Hi Im David, thanks for visiting the site. have you tested for spark with a spark tester?
when you turn the key to the run position(not start) can you hear the fuel pump run for a few seconds?
when it was running there was.
do you have anyone to put their ear to the fuel door and listen?
thats something i need to know to make sure the fuel pump is good.
should have unless you have multiple issues.
if you cant hear it, the pump is not being energized.
if it didnt fire when you put fuel in the intake, then you are missing spark too.
do you have a multi meter?
do you have a spark tester?
ill be back in half an hour. gotta walk the pooch.
good. while im gone could you please check for spark?
ok. keep in touch
ok. give us a starting point. when you turn the key to the on position(not start), does the check engine light come on?
good. ok, when you try to start the car does the red security light go out?
ok. good. let me pull a print so we can electrically test some things.
ok lets check some fuses. mainly the ones on this print, but anyone that has to do with IGN/ECU/FUEL/START/AM/EFI
HERES A LAYOUT
if the fuses are good. and the engine isnt getting spark or fuel, Double check the 7.5 amp ign. fuse. if that is good. your computer is fried.
the computer and the immobilizer has to be replaced as a set.
its part of the ignition switch. its a small black box located inside of the steering column.
probably easier and cheaper to get it off the donor
no, you'll need to new key made for the new ignition switch, the immobilizer and igniton switch come out as an assembly.
looks like this
yes, you can have new keys cut/programmed
the security light goes out when trying to start?
does the light flash when the key is out of the ignition and doors are shut?
ok, does the vehicle crank?
and still no fuel pump running for a few seconds when the key is on?
ok, gain access to the fuel pump relay. pull it out. with your multimeter find B+ on the relay base. then turn the key on and find switched power in another slot of the relay base. there should be 2 slots that doesnt ever have power also. take a jumper wire and put one end into a slot with 12vdc and the other end into a slot with no volts. ,key on, see if the pump runs
ok, now we need to know why it doesnt run with the key on.
i gotta go spend some time with my grand kids. ill be back on tonight
i dont think so. do you have a noid light?
its a light that plugs into each injectors connector to see if it is getting pulse command from the computer.
harbor freight sells a set really cheap
no power to any of the injectors?
you plugged it in to the connector and cranked the engine and no flashing?
ok. gimme a sec, thanks
can you check for ground at the one injector that you tested please.
heres a print
well the injector harness should run together and have a single gorund for all of them. ill talk to you tomorrow.
ok. see what happens to that ground when the key is turned on
ok. the ignition switch is sending power to the side of the injectors when turned on, which is what its supposed to do. next up is to do a continuity check of the fuel injector harness to the computer. check point to point. and also each wire to ground.
no. you are checking the control wires from the pcm to the fuel injectors.
if they all are good on the continuity test, then the computer is bad.
if the injector control wiring is good then yes. it cant be anything else. nothing stop the injectors from getting pulse except damaged wiring to the injectors a bad ignition switch or the computer. when you check continuity, make sure you check the grounds in the area of the computer for corrosion or looseness
after you ran the fuel pump, there was enough residual fuel in the lines and rail for it to be able to fire a couple times. did you check the wiring continuity?
we need to check for spark again. doesnt make sense
did you check for spark again?
is the red security light still go out when you try to start?
let me think about this
it has to be a fuse or a connector that not connected. recheck every fuse in the vehicle. even it you dont think it has anything to do with the problems.
what about the efi relay? lets see if we're getting power to it
you have a 2000 rx 300 correct?
they are correct