There are simple ways to diagnose if your fuel pump relay is functioning, If the fuel pump relay fails it can cause the fuel pump to run erratically or not at all causing stalling,crank but no start or no dealing with a crank but a no start issue. The only symptoms you are likely to notice from a bad (fuel) pump relay are that the fuel pump won't make its customary whirring sound when you turn on the key and that your 3.0 or 3.5L test results will tell you if the relay is defective, in this case, it'll need replacing. Ideally, the pump would power up for a couple of seconds and prime the fuel system in a well-functioning system. If you fail to hear this sound, the relay could be malfunctioning.
The most dependable method of checking the relay is with a multimeter to read for continuity and voltage. For a voltmeter, use this method which is in identifying the fuse box of relay in your car then unplug it out and check for voltage across its terminals. A broken relay will not display the desired voltage. And no reading or wrong one than the relay bad and need to replace it. Repair of a new fuel pump relay will be $20 inside $50 together with relatively small fix.
You could also replace the relay with a horn or head light where no harm will be done, as long as the relays are the same type and rating. This type of relay exists for other systems like the headlights or the air conditioning on many vehicles as well. Start up the vehicle and see if the fuel pump works, If it does then this proves that the relay you have swapped is faulty.
Some 5% of no-start problems with modern vehicles were related to dead or failed relays, a 2020 study by CarMD showed. When the fuel pump relay goes out, you generally get no power to the fuel pump so your vehicle will stall or not start at all.
A bad relay may also cause the lighting of the check engine light. The ECU is responsible for monitoring the fuel system, and in the event that any irregularities are present (i.e. low fuel pressure as a result of a faulty pump), it will set DTCs based on whatever fault condition has been detected. A mechanic will be able to read a code like P0230 (Fuel Pump Primary Circuit Malfunction) with an OBD-II scanner to make sure the relay is bad.
The smallest parts, said that well-known automotive expert and CEO Elon Musk, determine the destiny of the whole. This is true with a fuel pump relay, and having it fail can interrupt the flow of the whole fuel system causing major performance problems.
Finally, by listening for a fuel pump priming sound, checking voltage with amultimeter and swapping relays you should be able to determine weather the fuel pump relay is faulty or not. To diagnose or replace your fuel pump relay, visit Fuel Pump Sales.