Fuel pump not working properly

Hi,

If it is the fuel system that is not working, have you checked the inertia switch to see if resetting it fixes the problem? Take a look at pic 1 below.

The remaining pics are of the powertrain management system. I highlighted the wiring from the relay. I also highlighted two fuses. Make sure they are good. In addition, make sure there is power to and from them.

Note that the relay fuse powers the relay. It goes through a junction, so check that for power as well.

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below: Note I had to cut the schematics in half to make them readable. I did overlap them so you can follow one to the next.

Hi,

I looked through the schematics. For that fuse to get power, the ignition switch needs to be in the start position. If the fuse doesn't get power, we need to work backwards. It sounds like either you have an open circuit between the switch and the fuse, or the switch is bad.

Take a look below. Locate the white wire with a blue tracer behind the interior fuse box before it goes into the fuse. See if there is power with the key in the start position.

If there is no power, trace that wire back to the ignition switch. Note the wire color is not indicated at the switch, so you will need to follow the white/blue wire as far as possible to locate what it connects to. Since we know the wire color changes, there is a change it is a loose connection.

Let me know what you find or if you have other questions.

Joe

See pic below.

Hi,

If you are getting power to where it's needed, then the relay is likely causing the problem.

Take a look at the pic below. When you turn the key to the on or start position, power is supplied via both black/red wires. The blue/red completes the circuit for the relay. Once power goes in the black/red wire (left side of relay pic, 1) the circuit is completed by the blue/red wire. That draws the relay switch into the closed position (right side switched section of the relay). Once that internal switch is closed in the relay, power then runs from the fuel pump fuse, through the right section of the relay, and out the light green/red wire to the pump.

If you are not getting power to the light green/red wire, either the internal contact switch in the relay isn't closing, there is no power to the black/red at that portion of the relay, the connector to the light green wire is bad, or the fuse is bad.

Look at pics 1 and 2 (sorry it's so sloppy). The first thing that happens is the relay is powered (pic 1) indicated as step 1. Once power goes through the relay, it causes the contact to close (pic 2) creating a path to power the pump, the light green wire.

So, if you have power in and out as seen in pic 1, and there is power in as seen in pic 2, then the pump should get power. If the light green wire never gets power, recheck the relay and its connection (specifically to the light green wire).

I hope that makes sense. LOL I read through it a couple of times. If it doesn't. let me know.

Take care and let me know the results. Also, here is a link that shows how to test a relay.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Joe

See pics below.

Hi,

Before replacing the PCM, check to make sure the wire between the relay and PCM isn't broken. Also, make sure the pin at the PCM isn't damaged or corroded.

If you look at the attached pic, it shows the relay ground going to the PCM FPR ground. If you want to try something, run a jumper wire from the blue/red ground wire at the relay to a known good ground. When you provide the ground, you should feel the relay click. Then, pay attention if the fuel pump is running or check the light green wire for power.

Next, if you replace the PCM, is bad, you can get a remanufactured one online that is plug and play. Here is a link that I used for my own vehicle. I and the site have absolutely nothing to do with the site, so I'm not trying to sell you something. All I can tell you is I provided the info to them, and they provided me with a replacement PCM that was truly plug and play.

https://www.carcomputerexchange.com/

Let me know how things turn out for you.

Joe