This all started when I took the radio, climate control, and info center out of my sons GX470 to install an aftermarket navigation. The navigation we received was the wrong model, so it the install got postponed. However my son tried to start the vehicle with everything unplugged and it would just crank but not start as if it were not getting fuel.
I checked all the fuses (with an ohm meter) and had zero faults. I put the factory radio, climate control and info center back in and tried once again to start it with the same result. I replaced the Fuel pump real and circuit open relay simply because I keep them in stock. This changed nothing, so I began trouble shooting, below is where I am so far.
opened both fuel lines o driver side of engine, turned ignition to on (no fuel) turned ignition to crank position (no fuel). Since I have already checked all fuses in both location and replace two relays I was pretty certain it was simple.
I tried the emergency key, and followed the instruction to ensure the vehicle read the card with the key..same result, crank but no start.
I then checked battery voltage 12.83v
Next I accessed the fuel pump and checked voltage at the pump in both start and run positions and I had no voltage on the Black with red main power wire.
I then check continuity fromm the C/OPN relay ground to the FP relay ground, then I check continuity from the FB relay to the fuel pump resistor circuit.
Lastly I check continuity from the FP relay direct power (pin 3 I believe) and I had good continuity from the relay to the pump red/black wire.
At this point I am still getting no power to the fuel pump plug despite having continuity to it from the relay.
I dropped the fuel tan and pulled the pump, it bench tested prefect.
I used my power probe to inject 12v directly to the Red/black fuel pump wire at the relay (again pin 3 if I recall) and the 12v did not make it to the fuel pump plug.
So now I know that the problem is some place between the relay and the fuel pump plug, BUT I know the wire is in tact because I have Les than 1/2ohm of resistance in the wire.
Next I check voltage between E8 number 10pin and E6 numer 1 pin and get a voltage of 11.86
So I’m lost, I have a feeling something in the radio or surrounding has activated the immobilizer and it has killed the fuel supply to the the vehicle. However when I insert the key the security (red key) light goes off on the dash as if everything is good.
So if my circuit open relay checks out and the fuel pump relay checks out, why am I not getting any power to the fuel pump under any condition including injection power at the fuses box.
I know this is aLexus, but 5e Lexus guys do not work on their own stuff so I was hoping a 4th gen electrical guru would chime in.
I checked all the fuses (with an ohm meter) and had zero faults. I put the factory radio, climate control and info center back in and tried once again to start it with the same result. I replaced the Fuel pump real and circuit open relay simply because I keep them in stock. This changed nothing, so I began trouble shooting, below is where I am so far.
opened both fuel lines o driver side of engine, turned ignition to on (no fuel) turned ignition to crank position (no fuel). Since I have already checked all fuses in both location and replace two relays I was pretty certain it was simple.
I tried the emergency key, and followed the instruction to ensure the vehicle read the card with the key..same result, crank but no start.
I then checked battery voltage 12.83v
Next I accessed the fuel pump and checked voltage at the pump in both start and run positions and I had no voltage on the Black with red main power wire.
I then check continuity fromm the C/OPN relay ground to the FP relay ground, then I check continuity from the FB relay to the fuel pump resistor circuit.
Lastly I check continuity from the FP relay direct power (pin 3 I believe) and I had good continuity from the relay to the pump red/black wire.
At this point I am still getting no power to the fuel pump plug despite having continuity to it from the relay.
I dropped the fuel tan and pulled the pump, it bench tested prefect.
I used my power probe to inject 12v directly to the Red/black fuel pump wire at the relay (again pin 3 if I recall) and the 12v did not make it to the fuel pump plug.
So now I know that the problem is some place between the relay and the fuel pump plug, BUT I know the wire is in tact because I have Les than 1/2ohm of resistance in the wire.
Next I check voltage between E8 number 10pin and E6 numer 1 pin and get a voltage of 11.86
So I’m lost, I have a feeling something in the radio or surrounding has activated the immobilizer and it has killed the fuel supply to the the vehicle. However when I insert the key the security (red key) light goes off on the dash as if everything is good.
So if my circuit open relay checks out and the fuel pump relay checks out, why am I not getting any power to the fuel pump under any condition including injection power at the fuses box.
I know this is aLexus, but 5e Lexus guys do not work on their own stuff so I was hoping a 4th gen electrical guru would chime in.
