pbennison1

Hello everyone....

New member...I have never owned a Lexus...;my Dad recently passed away and he owned a 2012 ES350...my brothers and I have been using it for errands, but it is time to sell it now...a couple weeks ago the CEL came on..when I took the plastic cover off the engine it was clear that some type of rodent got into the engine and chewed on some wires going to the fuel injectors causing some misfiring...I spliced the wiring back together and the CEL went away....

the other day the CEL popped back on and this time it was only P0302....I have checked the wiring...swapped out the injectors, coil plug and spark plugs with number 4 and the misfire continues on number 2......

I have no idea where else to go on this one....I am fairly mechanical and usually can figure this stuff out...but..this one has me puzzled....I was thinking about just having it towed in and figured I would try this forum...I have been on forums before and they have helped tremendously...

Thanks for any ideas....Pat

ESh

So, check the coil, the injector and the wires.

pbennison1

Thanks for the quick reply....I changed out the #2 fuel injector and coil and the problem stayed on number 2. I did switch the fuel injector connectors between 2 and 4 and then got a misfire on both 2 and 4.

I guess I am not too familiar with these yet....all of my vehicles are pre 2008....

ESh

What you think which is the #2 coil/injector?

pbennison1

I assume the #2 is the one on the end on left side (passenger) looking at engine from front. I changed out the 2 and 4 (middle) coil/injector one at a time and the issue continued to be on #2. In other words I now have #4 coil/injector in #2 and vice versa.

That makes me think there is a problem in the wiring possibly?

nevernu

>>it was clear that some type of rodent got into the engine and chewed on some wires going to the fuel injectors causing some misfiring...I spliced the wiring back together...


you think it might be the wiring ?

ESh

I think so.

pbennison1

So, yes I feel stupid....but...is there a definitive way to check the wiring from the injector back to wherever it ends?

ESh

Uh, you need the wiring diagram.
Nevernu will give you all the details.

pbennison1

Thanks for your patience. I took a picture and did some voltage readings. In the picture from left to right there is the injector wires. The red and white go to injector 2 and the blue and white go to injector 4 and brown and white go to 6. Now here is the interesting part.

When power is off all three white wires go to ground, I have verified this by clipping one end of multimeter to negative battery and testing each one.

When I turn the power on, the brown, red and blue show 12 volts, but, number 2 white wire also shows 12 volts.

So, I think I have narrowed it down. The easy answer would be to splice into a known good ground (4 or 6) and cap off the bad one. I like easy but I also like right.

I guess I will wait until I can take a look at the wiring diagram.

Thanks again for all the help and if I see one of those rodents around.....well...whatever...

nevernu

maybe some of this is useful

ESh

Try to swap the coils.

pbennison1

Thanks..any chance I could get the wiring diagram for injectors 2, 4 and 6?

nevernu

pg 2 of the is.pdf?

pbennison1

It looks like those are for the coils, not the injectors?