Have Toyota Questions? Ask a Mechanic for Answers ASAP
Turn the key to the on position is the yellow check engine light illuminated? The car ran perfectly fine prior to doing the work with the fuel pump and relay? Do you have the vehicle identification number available?
Did you make sure that you got the relay back in the right spot? Some of those junction blocks do not have relays in all of the spots that can accommodate one.
Okay I just want to rule out any fuel pump related issue. Provided nothing else was disconnected or damaged behind the junction block then that should be okay. This takes us back to the four codes that you have set each one of these codes means that the computer did not see the ignition trigger or the feedback signal from the computer to each individual coil. Here's how the system is supposed to work. The camshaft position sensor and the crankshaft position sensor send a signal to the computer the engine control computer then determines when to fire the spark. To do that it sends a trigger signal out to the ignition coil on the off-color wire. The black wire with a white tracer at each ignition coil should have 12 V with the key in the on position. Disconnect each connector and check that. The brown wire should have less than .4 ohms of resistance to ground. The blue wire with a yellow tracer at each ignition coil is the trigger or feedback signal to the computer. Once the computer sends out the trigger signal on the off-color wire to each coil the coil fires and the signal or feedback goes back the Blue with the yellow tracer on each coil. What I have seen happen on this car is you will have one coil that will fail and it shorts out the feedback signal on the blue wire with a yellow tracer. All four coils come to a junction connector and share a common single feedback signal wire blue/yellow wire to the engine control computer. If one coil shorts out it will take down the rest of them and set all four codes. So what I need you to do is take one coil at a time and plug it into one of the four connectors \ start the engine or to attempt to start it after you have cleared the codes see what codes set or come back. Do all four codes set or is there one of the four codes missing. Do you understand what I'm trying to get you to do? If there's one single coil that failed and it's plugged in and you continually get all four codes then that coil is bad. If the other three coils only set three malfunction codes and the cylinder that that coil is plugged into reports as good and that ignition coil sparks then you know the coil is good. Let me know how this goes.